Hypertension
Clinical Snapshot
Hypertension is chronic elevation of arterial blood pressure. Regulation of blood pressure is complex — the autonomic nervous system, the renin-angiotensin-aldosterone system, cardiac output, vascular tone, and renal salt/water handling all contribute, and obesity and vascular stiffness are two of the most important drivers of rising blood pressure with age. Sustained elevation damages the heart, brain, kidneys, and blood vessels over time, and hypertension is the leading modifiable contributor to stroke, myocardial infarction, heart failure, atrial fibrillation, chronic kidney disease, and dementia.[1]
The 2025 Hypertension Canada primary care guideline makes two changes that reshape day-to-day management: it redefines hypertension as blood pressure consistently ≥130/80 mmHg on correctly performed measurement (down from the older 140/90 mmHg threshold), and it replaces sequential monotherapy with a low-dose single-pill combination — typically an ACE inhibitor or ARB plus a thiazide/thiazide-like diuretic — as the default first step for most adults starting drug therapy.[1] The degree of blood pressure reduction achieved matters more to cardiovascular risk reduction than which specific drug class is used to get there, which is part of why combining two lower-dose agents from complementary classes is now preferred over pushing a single agent to its maximum dose.[1]
Recognize the Condition
Usually silent
Hypertension is typically asymptomatic. Most patients feel entirely well, and blood pressure is found incidentally on screening rather than because of symptoms — do not wait for symptoms to prompt measurement. When symptoms are present they are nonspecific (headache, dizziness) and do not reliably track with the degree of elevation, except in a true hypertensive emergency (see Red Flags & Refer). Opportunistic screening at every applicable visit, and at minimum annually, is how most hypertension is actually found.[1]
Patterns of blood pressure on office versus out-of-office measurement
The same office reading can mean very different things depending on how it compares with out-of-office (home or ambulatory) measurement — recognizing which pattern is present changes whether treatment is started at all.
Sustained hypertension
Blood pressure is elevated on both a properly performed office reading and out-of-office measurement (a home BP series or ambulatory BP monitoring). This is genuine hypertension requiring treatment.
White-coat hypertension
Blood pressure is elevated in the office but normal on out-of-office measurement, in a patient not already on antihypertensive therapy. This is not "nothing" — it carries higher long-term cardiovascular risk than true normotension — but treatment is not started on the basis of office readings alone; continue periodic monitoring instead.
Masked hypertension
Blood pressure is normal in the office but elevated on out-of-office measurement — easy to miss entirely, since the office reading looks reassuring. Suspect it in a patient with target-organ damage or otherwise elevated cardiovascular risk despite normal-looking office readings, and confirm with home or ambulatory monitoring.
White-coat effect (in a patient already being treated)
Office blood pressure is above target despite out-of-office blood pressure being at target. Distinguishing this from true treatment-resistant hypertension changes management entirely — do not intensify therapy based on an elevated office reading alone; confirm with out-of-office measurement first.
Risk Factors
- Age.
- Family history of hypertension.
- Overweight or obesity, particularly abdominal obesity.
- Sedentary lifestyle.
- High dietary sodium intake; low dietary potassium intake.
- Excess alcohol intake.
- Smoking.
- Diabetes mellitus.
- Dyslipidemia.
- Chronic kidney disease.
- Obstructive sleep apnea.
- Hypertension during a prior pregnancy.
- Chronic psychological stress.
Drugs and other exogenous factors that can induce or aggravate hypertension
Review every patient's medication and substance-use history for these contributors before assuming a hypertension diagnosis is purely primary — this is a genuinely reversible or modifiable factor in some patients.
- Alcohol (excessive use).
- Bruton tyrosine kinase inhibitors (e.g., ibrutinib, zanubrutinib).
- Calcineurin inhibitors (e.g., cyclosporine, tacrolimus).
- Corticosteroids and anabolic steroids.
- Erythropoietin and analogues.
- Licorice root.
- Midodrine.
- Monoamine oxidase inhibitors (MAOIs).
- NSAIDs, including COX-2 inhibitors.
- Oral contraceptives and other sex hormones.
- High dietary sodium (salt) intake.
- Selective serotonin reuptake inhibitors (SSRIs).
- Serotonin-norepinephrine reuptake inhibitors (SNRIs).
- Stimulants, including cocaine.
- Vasoconstricting, sympathomimetic decongestants.
Red Flags & Refer
Confirmed severe blood pressure elevation together with new or progressive target-organ involvement is a hypertensive emergency and needs immediate emergency department referral for continuous monitoring — this is not managed as routine outpatient hypertension.
- Diastolic BP ≥130 mmHg.
- Hypertensive encephalopathy, acute coronary syndrome, acute heart failure/pulmonary edema, or rapidly worsening kidney function occurring together with severe BP elevation.
- Hypertension together with a suspected major-artery (aortic) dissection.
- Severe hypertension in pregnancy (SBP ≥160 mmHg or DBP ≥110 mmHg) — refer urgently for specialist-directed management (see Special Populations).
Also investigate for a secondary, potentially correctable cause of hypertension — and refer to a hypertension specialist, nephrologist, or endocrinologist as appropriate — for any of the following:
- Sudden onset or sudden worsening of hypertension, particularly at age under 30 or over 55.
- Hypertension resistant to an optimally dosed 3-drug regimen that includes a diuretic.
- Spontaneous hypokalemia, or hypokalemia disproportionate to the diuretic dose used.
- Paroxysmal or severe sustained hypertension refractory to usual therapy, especially together with headache, palpitations, and sweating (catecholamine-excess symptoms).
- Hypertension specifically triggered by beta-blockers, monoamine oxidase inhibitors, urination, or changes in abdominal pressure.
- An incidentally discovered adrenal adenoma.
- A personal or family history of MEN 2A/2B, neurofibromatosis, or von Hippel-Lindau disease.
- An abdominal bruit.
- Declining kidney function after starting an ACE inhibitor or ARB.
- Recurrent flash pulmonary edema.
- Overt atherosclerotic vascular disease with uncontrolled hypertension despite 3 or more drugs.
Assessment & Diagnosis
History
- Duration of hypertension, usual BP level, any sudden change in severity, and any prior hospitalization or emergency visit for hypertensive urgency/emergency.
- Home BP monitoring use, technique, and device (confirm a validated device and correct cuff size), home readings, and any discrepancy from office values.
- Prior antihypertensive drug use — reason for changing or stopping, effectiveness, side effects, and intolerance.
- Drugs or substances that may be causing or aggravating hypertension (see Risk Factors), and drugs that may interact with antihypertensive therapy.
- Adherence to lifestyle recommendations and drug therapy.
- Family history of hypertension, cardiovascular risk factors, and premature cardiovascular disease.
- Smoking and alcohol use, usual physical activity, usual diet and sodium intake, current weight/recent weight change, waist circumference, diabetes, dyslipidemia, and hypertension during a prior pregnancy.
- Cerebrovascular, cardiac, and peripheral vascular symptoms suggesting target-organ damage.
- Symptoms of secondary hypertension — e.g., catecholamine-excess symptoms (pheochromocytoma), hyper-/hypothyroid symptoms, Cushingoid features, or renal/urinary symptoms or a past history of renal disease.
Diagnostic technique
Use a validated automated oscillometric device and a standardized technique — automated office BP (AOBP) is the preferred office/pharmacy method, taking the mean of several automated readings (usually 3-6) with the patient unattended, which minimizes white-coat effect. All in-office measurement remains susceptible to white-coat effect, so out-of-office measurement is required to confirm the diagnosis — either a home BP series (2 readings each morning and evening for 7 days, discard the first day, and average the remaining 24 readings) or 24-hour ambulatory BP monitoring, which is considered the gold standard and is preferred when available. Hypertension is diagnosed when the mean BP is consistently ≥130/80 mmHg.[1]
Physical exam
- Fundoscopy for hypertensive retinopathy.
- Bruits and peripheral pulses for vascular disease or renovascular hypertension.
- Edema and lung fields for signs of heart failure.
- Heart sounds (a fourth heart sound suggests reduced left ventricular compliance).
- Sustained, displaced apex beat suggesting left ventricular hypertrophy.
- Abdominal mass suggesting polycystic kidneys or aortic aneurysm.
- Neurologic exam for cerebrovascular disease.
- Femoral-radial pulse delay and any murmur suggesting aortic coarctation.
Initial investigations
- Serum potassium, sodium, and creatinine.
- Urinalysis; urine albumin and/or albumin-creatinine ratio in patients with diabetes.
- Fasting glucose and/or HbA1c.
- Lipid panel (total cholesterol, HDL-C, LDL-C, triglycerides — fasting or non-fasting).
- Standard 12-lead ECG.
- Consider renin and aldosterone levels in medication-naive patients.
- Perform a global cardiovascular risk assessment (e.g., Framingham) in every hypertensive patient — this independently determines both the treatment-initiation threshold and target (see Treatment Targets).
Secondary hypertension: when to investigate for a specific cause
Order the targeted work-up below only when the corresponding trigger findings are present — routine screening of every hypertensive patient for these causes is not indicated.
Pheochromocytoma
Suspect with paroxysmal and/or severe sustained hypertension refractory to usual therapy; hypertension with catecholamine-excess symptoms (2 or more of headache, palpitations, sweating); hypertension triggered by beta-blockers, MAOIs, urination, or abdominal pressure change; an incidentally discovered adrenal adenoma; or a personal/family history of MEN 2A/2B, neurofibromatosis, or von Hippel-Lindau disease.
Primary hyperaldosteronism
Suspect with spontaneous hypokalemia; profound diuretic-induced hypokalemia; hypertension refractory to treatment with 3 or more drugs; or an incidental adrenal adenoma.
Renovascular disease
Suspect with 2 or more of: sudden onset or worsening of hypertension at age over 55 or under 30; an abdominal bruit; uncontrolled hypertension despite 3 or more drugs; declining kidney function associated with starting an ACE inhibitor or ARB; overt atherosclerotic vascular disease; or recurrent episodes of hypertension with flash pulmonary edema.
Treatment Targets
- Reduce the risk of stroke, myocardial infarction, heart failure, and other cardiovascular and renal complications.
- Achieve a target systolic BP under 130 mmHg, provided this is well tolerated — the current guideline uses one simplified systolic target for most adults rather than separate population-specific numeric targets.[1]
- Start drug therapy for BP ≥140/90 mmHg in average-risk adults.
- Start drug therapy earlier, at SBP 130-139 mmHg, in adults at high cardiovascular risk: established cardiovascular disease (coronary artery disease, heart failure, cerebrovascular disease, peripheral artery disease); type 1 or type 2 diabetes mellitus; chronic kidney disease (eGFR under 60 mL/min/1.73m² or albuminuria ≥3 mg/mmol); a 10-year Framingham Risk Score ≥20%; or age ≥75 years.
- If SBP is 130-139 mmHg and the patient is not high risk, start with healthy lifestyle changes alone, continue monitoring BP and other risk factors, and reassess the need for drug therapy every 6-12 months rather than starting a drug immediately.
- Individualize the target in very old age, significant frailty, symptomatic orthostatic hypotension, or limited life expectancy — do not automatically withhold treatment, but do not pursue the under-130 target rigidly either (see Special Populations).
- Minimize the adverse effects of antihypertensive therapy.
Choose Initial Treatment
Most adults without a compelling comorbid indication
1st line a low-dose single-pill combination (SPC) of an ACE inhibitor or ARB plus a thiazide/thiazide-like diuretic — for example irbesartan/hydrochlorothiazide starting at half of the 150/12.5 mg tablet once daily. Reassess at 4-6 weeks and increase to the full-strength SPC (doubling the dose) if BP is not yet at target.
If a single-pill combination is unavailable or not covered, use 2 separate pills from the same 2 classes instead, preferring a long-acting thiazide-like diuretic (chlorthalidone or indapamide) over hydrochlorothiazide.
If the patient is at high risk of symptomatic hypotension (e.g., significant frailty, very advanced age, fall risk), starting with a single agent rather than a 2-drug combination is reasonable.
Add-on therapy when not at target
If BP remains above target on a full-dose 2-drug single-pill combination, add — never substitute — a long-acting dihydropyridine calcium channel blocker such as amlodipine as the third agent, building the standard 3-class regimen (ACE inhibitor or ARB + thiazide-like diuretic + dihydropyridine CCB).
Resistant hypertension — BP above target despite 3 optimally dosed drugs including a diuretic: add spironolactone once adherence is confirmed and white-coat effect has been excluded with out-of-office measurement (see Treatment Failure & Next Step).[2]
Beta-blockers
Do not use a beta-blocker as routine initial therapy in patients over 60 without a compelling indication. Reserve beta-blockers for a specific compelling reason — recent MI, heart failure, angina, atrial fibrillation rate control, migraine prophylaxis, or essential tremor.
Never combine
Never combine an ACE inhibitor with an ARB — this combination adds no cardiovascular benefit and consistently increases the risk of hypotension, hyperkalemia, and acute kidney injury, across every compelling-indication category below.
Initial therapy by compelling comorbid indication
When one of these conditions is present, select the indication-specific agent below instead of defaulting to the general single-pill-combination pathway.
Diabetes mellitus with albuminuria, renal disease, cardiovascular disease, or additional cardiovascular risk factors
1st line: an ACE inhibitor or ARB. If further BP lowering is needed, add a dihydropyridine CCB in preference to a thiazide diuretic. A loop diuretic can be considered if extracellular fluid volume overload is present with chronic kidney disease.
Diabetes mellitus without the above features
1st line: an ACE inhibitor, ARB, long-acting dihydropyridine CCB, or thiazide diuretic. If combining with an ACE inhibitor, a dihydropyridine CCB is preferred over a thiazide diuretic.
Coronary artery disease
1st line: an ACE inhibitor or ARB; a beta-blocker or CCB for patients with stable angina. When combination therapy is needed in a high-risk patient, an ACE inhibitor plus a dihydropyridine CCB is preferred. Avoid short-acting nifedipine.
Recent myocardial infarction
1st line: a beta-blocker plus an ACE inhibitor (an ARB if the ACE inhibitor is not tolerated). A long-acting CCB is a second-line addition; non-dihydropyridine CCBs should not be used with concomitant heart failure.
Heart failure
1st line: an ACE inhibitor and a beta-blocker (an ARB if the ACE inhibitor is not tolerated), with a mineralocorticoid receptor antagonist added for a recent cardiovascular hospitalization, acute MI, elevated natriuretic peptides, or NYHA class II-IV symptoms. An angiotensin receptor-neprilysin inhibitor can replace the ACE inhibitor/ARB if the patient remains symptomatic. Titrate ACE inhibitor/ARB doses to those used in clinical trials, and monitor serum potassium and creatinine closely with an ARNI, ACE inhibitor, ARB, or mineralocorticoid receptor antagonist.
Left ventricular hypertrophy
1st line: an ACE inhibitor, ARB, long-acting CCB, or thiazide diuretic. Hydralazine and minoxidil should not be used for this indication.
Past stroke or TIA
1st line: an ACE inhibitor/diuretic combination. Do not treat hypertension in the acute stroke setting unless BP is extremely elevated.
Nondiabetic chronic kidney disease with proteinuria
1st line: an ACE inhibitor (an ARB if not tolerated), with a diuretic as additive therapy. Monitor serum potassium and creatinine closely.
Renovascular disease
Does not change the initial drug choice, but avoid ACE inhibitors or ARBs in bilateral renal artery stenosis or unilateral disease with a solitary kidney.
Peripheral arterial disease
Does not change the initial drug choice; avoid beta-blockers in severe disease.
Non-Pharmacologic Treatment
Advise every patient — treated or not yet on drug therapy — on a healthy lifestyle to prevent or control hypertension and cardiovascular risk overall:
- Weight loss if overweight, targeting a BMI of 18.5-24.9 kg/m² and a waist circumference under 102 cm (men) or 88 cm (women).
- A healthy diet high in fresh fruits, vegetables, soluble fibre, and low-fat dairy, and low in saturated fat and sodium — e.g., a DASH-style eating plan.
- Sodium intake under 2000 mg (88 mmol) per day.
- Increase dietary potassium (e.g., the fruit/vegetable component of a DASH-style diet) unless the patient is at risk of hyperkalemia — renin-angiotensin-system inhibitor use, other potassium-raising drugs, chronic kidney disease, or a serum potassium above 4.5 mmol/L.
- Regular, moderate-intensity cardiorespiratory physical activity for 30-60 minutes on most days of the week.
- Low-risk alcohol consumption — no more than 0-2 standard drinks per week.
- A smoke-free environment.
Home blood pressure monitoring technique
Recommend a validated, Hypertension Canada-endorsed home BP monitor and train the patient in correct technique (proper cuff size, seated position, arm supported at heart level, no talking during measurement). Use a home BP series to confirm a diagnosis or assess control: 2 readings each morning and evening for 7 days, discard the first day's readings, and average the remaining 24 readings. Reassure patients that some variation in BP throughout the day is normal — the goal is the trend, not any single reading.
Supporting adherence
Poor adherence is a major, correctable cause of uncontrolled blood pressure. Build these strategies into routine care:
- Ensure the patient understands hypertension and its treatment, ideally with both verbal counselling and written patient information.
- Involve family or social support in lifestyle changes.
- Use a simplified regimen — long-acting, once-daily drugs, and a single-pill combination product where appropriate — rather than multiple separate pills.
- Confirm the patient can access and afford the prescribed drugs.
- Anchor pill-taking to an existing daily routine (e.g., alongside brushing teeth).
- For patients with confirmed poor adherence: identify and address the specific reason, consider a dosette box or other adherence-enhancing dispenser, encourage home BP self-monitoring, use pill counts or a marked calendar for refill timing, and involve regular follow-up contact or social work support where needed.
Special Populations
Pregnancy
Pre-existing hypertension in pregnancy carries a genuinely heightened risk of preeclampsia, along with intrauterine growth restriction, placental abruption, and preterm delivery — enhanced surveillance with an obstetrician or perinatologist is warranted. Review antihypertensive therapy before conception, or immediately on recognizing an unplanned pregnancy, and switch to an agent with a better pregnancy safety profile.[3]
Offer ASA 81-162 mg once daily at bedtime to every patient at high risk of preeclampsia — which includes all patients with chronic hypertension — starting after conception but before 16 weeks' gestation, and continued to around 36 weeks.[4] Patients with a low dietary calcium intake should receive at least 500 mg of oral calcium daily.[3]
Start antihypertensive therapy for sustained BP over 140/90 mmHg, targeting 120-140/80-90 mmHg. Preferred agents are labetalol (100 mg BID up to 800 mg TID) and nifedipine extended-release (30 mg once daily up to 60 mg BID); methyldopa (250 mg BID up to 1000 mg TID) is also acceptable but chosen less often given lower potency and a higher side-effect burden. Other oral beta-blockers (acebutolol, metoprolol, pindolol, propranolol) can be considered but are used infrequently.
For acute severe hypertension in pregnancy (SBP ≥160 mmHg or DBP ≥110 mmHg), lower BP rapidly with immediate-release oral nifedipine 5-10 mg every 30 minutes as required, IV labetalol 20 mg then 20-80 mg every 30 minutes as required, or IV hydralazine 5 mg then 5-10 mg every 30 minutes as required — specialist/hospital-directed.[3]
Avoid atenolol in pregnancy specifically — it is associated with fetal intrauterine growth restriction, unlike other beta-blockers, which carry only a weak association. Avoid spironolactone entirely due to anti-androgenic effects. Thiazide/loop diuretics may impair uteroplacental perfusion and should be avoided when perfusion is already reduced (preeclampsia, IUGR), though they can be continued in a patient with volume-dependent hypertension from renal impairment.
ACE inhibitors, ARBs, and direct renin inhibitors are contraindicated — fetotoxic in the second/third trimester (oligohydramnios, IUGR, fetal/neonatal renal failure) and associated with teratogenic effects on first-trimester exposure. Discontinue before conception or immediately on discovering an unplanned pregnancy; cautious continuation with frequent pregnancy testing may be considered only in proteinuric renal disease.[3]
Breastfeeding
Labetalol, nifedipine extended-release, and methyldopa are all considered safe to continue while breastfeeding. If an ACE inhibitor is strongly favoured, captopril, enalapril, benazepril, and quinapril are the preferred agents given lower transfer into breast milk.
Older adults
Use a lower starting dose in older patients, who are often more sensitive to blood-pressure-lowering effects. Beta-blockers are not recommended as initial therapy over age 60 without a compelling indication. A single-pill combination remains reasonable in a fit older adult, but in very old or significantly frail patients — particularly age ≥85, symptomatic orthostatic hypotension, or a limited predicted lifespan — individualize the target rather than rigidly pursuing systolic BP under 130 mmHg, and avoid starting with combination therapy unless BP is very high; a long-acting dihydropyridine CCB is a reasonable single starting agent, followed by a low-dose thiazide/thiazide-like diuretic if further lowering is needed. Do not automatically deprescribe antihypertensive therapy in a frail patient who is tolerating it well, but review the regimen regularly, since progressive frailty can itself lower BP and eventually require deprescribing. Avoid vasodilating beta-blockers, direct vasodilators, and alpha1-blockers where possible in very frail patients given a higher orthostasis risk.[5]
Renal impairment
Thiazide diuretics become ineffective once creatinine clearance falls below 30-40 mL/min — switch to a loop diuretic instead. An ACE inhibitor or ARB is preferred in proteinuric chronic kidney disease, with close monitoring of potassium and creatinine after starting or increasing the dose. Never combine an ACE inhibitor with an ARB. Avoid ACE inhibitors/ARBs in bilateral renal artery stenosis or unilateral stenosis with a solitary kidney.
Diabetes
An ACE inhibitor or ARB is preferred first-line, especially with albuminuria, renal disease, cardiovascular disease, or additional cardiovascular risk factors — add a dihydropyridine CCB in preference to a thiazide diuretic if further BP lowering is needed in this group.
Hepatic impairment
Use lower starting and maximum doses of ACE inhibitors and other hepatically metabolized agents in significant hepatic impairment, and monitor clinical response and adverse effects more closely.
Monitoring & Follow-Up
Titrate therapy approximately every 4 weeks in most patients; use closer follow-up and more frequent titration for severe hypertension, target-organ damage, or high cardiovascular risk. Recheck BP 2-4 weeks after any dose change or new drug. Uncontrolled BP is most often a failure to titrate therapy in response to elevated readings, not true treatment resistance — supplement office readings with home or ambulatory measurement to build confidence in the true BP before intensifying therapy. Assess medication adherence at every visit. Check serum potassium and creatinine within days of starting or increasing an ACE inhibitor, ARB, or potassium-sparing diuretic/spironolactone, then periodically thereafter. Reassess global cardiovascular risk and screen for target-organ damage on an ongoing basis. For a patient managed with lifestyle measures alone (SBP 130-139 mmHg, not high risk), reassess the need for drug therapy every 6-12 months. There is no advantage to routinely moving antihypertensive dosing to bedtime — evening dosing does not improve cardiovascular outcomes compared with morning dosing.[6]
Common Errors to Avoid
- Diagnosing or intensifying treatment based on unstandardized or nonvalidated office BP readings without out-of-office confirmation.
- Substituting a new drug for an existing one instead of adding a complementary-class agent when the first drug alone is not enough.
- Using a beta-blocker as routine initial therapy, especially in patients over 60, without a compelling indication.
- Combining an ACE inhibitor with an ARB — no added benefit, more harm, across every indication.
- Assuming routine bedtime dosing improves cardiovascular outcomes — the TIME trial found no benefit of evening over morning dosing, so dose timing should be chosen for adherence, not a presumed outcome advantage.[6]
- Missing a hypertension-aggravating drug or substance (NSAIDs, decongestants, licorice, oral contraceptives) as a reversible contributor to poor control.
- Using short-acting (immediate-release) nifedipine for chronic essential hypertension — reserved only for acute severe hypertension in pregnancy.
- Labelling a patient "resistant" without first excluding white-coat effect and nonadherence via out-of-office measurement.
- Missing secondary-hypertension clues (see Red Flags & Refer) and simply cycling through more antihypertensive classes instead of investigating or referring.
- In pregnancy: continuing an ACE inhibitor or ARB after conception, using atenolol, or forgetting ASA for preeclampsia prevention in a patient with chronic hypertension.
- Stopping a beta-blocker or clonidine abruptly — both require tapering to avoid rebound hypertension or ischemia.
Clinical Decision Algorithm
Drug Tables
How to use this table: Doses are adult doses and require patient-specific confirmation (renal/hepatic function, weight, allergy history). Pediatric dosing is weight-based per the current product monograph unless stated. Drug pricing is intentionally omitted. Select any drug name to open its complete Pharmasist Drug Database page.
Alpha1-Adrenergic Antagonists
Not used as initial hypertension therapy; reserved for special situations such as resistant hypertension or symptomatic benign prostatic hyperplasia.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Doxazosin | Initial: 1 mg PO once daily Usual: 1-8 mg PO once daily Maximum: 16 mg PO once daily | Orthostatic hypotension, headache, drowsiness, palpitations, nasal congestion; syncope most likely at treatment start or with rapid titration | Additive hypotension with other antihypertensive drugs | Not for initial therapy. Titrate slowly; if therapy is interrupted for several days, restart at the initial dose. |
| Prazosin | Initial: 0.5 mg PO with the evening meal on day 1, then 0.5 mg PO BID-TID for 3 days Titration: Increase gradually as required Maximum: 20 mg/day | Orthostatic hypotension, headache, drowsiness, palpitations, nasal congestion; syncope most likely at treatment start | Additive hypotension with other antihypertensive drugs | Not for initial therapy. First dose given with the evening meal to reduce first-dose syncope risk. |
| Terazosin | Initial: 1 mg PO at bedtime Usual: 1-5 mg PO once daily Maximum: 20 mg/day | Orthostatic hypotension, headache, drowsiness, palpitations, nasal congestion; syncope most likely at treatment start | Verapamil increases terazosin serum concentrations | Not for initial therapy. Titrate slowly; if therapy is interrupted for several days, restart at the initial dose. |
ACE Inhibitors
First-line only as part of a single-pill combination with a thiazide/thiazide-like diuretic, or for a specific compelling indication. Never combine with an ARB. Contraindicated in pregnancy.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Benazepril | Initial: 10 mg PO once daily Usual: 20 mg PO once daily Maximum: 40 mg/day, once daily or divided BID | Dry cough, hyperkalemia, rare angioedema; can precipitate renal failure in renovascular disease, volume depletion, or with NSAID use | Marked increase in serum potassium with potassium supplements/potassium-sparing diuretics; reduced hypotensive effect and increased renal-dysfunction risk with NSAIDs; may raise lithium levels | Use a lower initial dose if already on a diuretic. Check creatinine and potassium within days of starting, then periodically. |
| Captopril | Initial: 25 mg/day Usual: 75 mg/day Maximum: 150 mg/day, divided BID-TID | Dry cough, hyperkalemia, rare angioedema; can precipitate renal failure in renovascular disease, volume depletion, or with NSAID use | Same as other ACE inhibitors | Use a lower initial dose if already on a diuretic. |
| Cilazapril | Initial: 2.5 mg PO once daily Usual: 2.5-5 mg PO once daily Maximum: 10 mg/day, once daily or divided BID | Dry cough, hyperkalemia, rare angioedema; can precipitate renal failure in renovascular disease, volume depletion, or with NSAID use | Same as other ACE inhibitors | Use a lower initial dose if already on a diuretic. |
| Enalapril | Initial: 5 mg PO once daily Usual: 10-40 mg PO once daily Maximum: 40 mg/day, once daily or divided BID | Dry cough, hyperkalemia, rare angioedema; can precipitate renal failure in renovascular disease, volume depletion, or with NSAID use | Same as other ACE inhibitors | Use a lower initial dose if already on a diuretic. |
| Fosinopril | Initial: 10 mg PO once daily Usual: 20 mg PO once daily Maximum: 40 mg/day, once daily or divided BID | Dry cough, hyperkalemia, rare angioedema; can precipitate renal failure in renovascular disease, volume depletion, or with NSAID use | Same as other ACE inhibitors | Use a lower initial dose if already on a diuretic. |
| Lisinopril | Initial: 10 mg PO once daily Usual: 20 mg PO once daily Maximum: 40 mg PO once daily | Dry cough, hyperkalemia, rare angioedema; can precipitate renal failure in renovascular disease, volume depletion, or with NSAID use | Same as other ACE inhibitors | Use a lower initial dose if already on a diuretic. |
| Perindopril | Initial: 4 mg PO once daily Maximum: 8 mg/day, once daily or divided BID | Dry cough, hyperkalemia, rare angioedema; can precipitate renal failure in renovascular disease, volume depletion, or with NSAID use | Same as other ACE inhibitors | Use a lower initial dose if already on a diuretic. |
| Quinapril | Initial: 10 mg PO once daily Maximum: 40 mg/day, once daily or divided BID | Dry cough, hyperkalemia, rare angioedema; can precipitate renal failure in renovascular disease, volume depletion, or with NSAID use | Same as other ACE inhibitors | Use a lower initial dose if already on a diuretic. |
| Ramipril | Initial: 2.5 mg PO once daily Usual: 10 mg PO once daily Maximum: 20 mg/day, once daily or divided BID | Dry cough, hyperkalemia, rare angioedema; can precipitate renal failure in renovascular disease, volume depletion, or with NSAID use | Same as other ACE inhibitors | Use a lower initial dose if already on a diuretic. Widely used as the compelling-indication ACE inhibitor of choice post-MI and in high cardiovascular risk. |
| Trandolapril | Initial: 1 mg PO once daily Maximum: 4 mg PO once daily | Dry cough, hyperkalemia, rare angioedema; can precipitate renal failure in renovascular disease, volume depletion, or with NSAID use | Same as other ACE inhibitors | Use a lower initial dose if already on a diuretic. |
Angiotensin II Receptor Blockers (ARBs)
First-line only as part of a single-pill combination with a thiazide/thiazide-like diuretic, or for a specific compelling indication; generally better tolerated than ACE inhibitors given a lower cough rate. Never combine with an ACE inhibitor. Contraindicated in pregnancy.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Azilsartan | Initial: 40 mg PO once daily Maximum: 80 mg PO once daily | Hyperkalemia; can precipitate renal failure in renovascular disease, volume depletion, or with NSAID use | Marked increase in serum potassium with potassium supplements/potassium-sparing diuretics; reduced hypotensive effect and increased renal-dysfunction risk with NSAIDs; may raise lithium levels | Use a lower initial dose if volume depleted or on a diuretic. |
| Candesartan | Initial: 8 mg PO once daily Usual: 8-16 mg PO once daily | Hyperkalemia; can precipitate renal failure in renovascular disease, volume depletion, or with NSAID use | Same as other ARBs | Use a lower initial dose if volume depleted or on a diuretic. |
| Irbesartan | Initial: 150 mg PO once daily Usual: 150-300 mg PO once daily | Hyperkalemia; can precipitate renal failure in renovascular disease, volume depletion, or with NSAID use | Same as other ARBs | Anchor drug of the current preferred initial single-pill combination with hydrochlorothiazide. |
| Losartan | Initial: 50 mg PO once daily Usual: 25-100 mg/day, once daily or divided BID Maximum: 100 mg/day | Hyperkalemia; can precipitate renal failure in renovascular disease, volume depletion, or with NSAID use | Same as other ARBs | Use a lower initial dose if volume depleted or on a diuretic. |
| Olmesartan | Initial: 20 mg PO once daily Maximum: 40 mg PO once daily | Hyperkalemia; can precipitate renal failure in renovascular disease, volume depletion, or with NSAID use | Same as other ARBs | Use a lower initial dose if volume depleted or on a diuretic. |
| Telmisartan | Initial: 80 mg PO once daily Usual: 80 mg PO once daily | Hyperkalemia; can precipitate renal failure in renovascular disease, volume depletion, or with NSAID use | Same as other ARBs | Use a lower initial dose if volume depleted or on a diuretic. |
| Valsartan | Initial: 80 mg PO once daily Usual: 80-320 mg PO once daily | Hyperkalemia; can precipitate renal failure in renovascular disease, volume depletion, or with NSAID use | Same as other ARBs | Use a lower initial dose if volume depleted or on a diuretic. |
Beta-Blockers — Non-Selective
Not first-line for uncomplicated hypertension; reserve for a compelling indication. Taper rather than stop abruptly — abrupt withdrawal can precipitate rebound hypertension and ischemia. Avoid in asthma; contraindicated in 2nd-/3rd-degree heart block without a pacemaker; avoid in severe peripheral arterial disease.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Nadolol | Initial: 20 mg PO once daily Usual: 160 mg PO once daily Maximum: 320 mg/day | Fatigue, bradycardia, reduced exercise capacity, headache, erectile dysfunction, vivid dreams; can unmask heart failure or heart block | Additive bradycardia with digoxin, non-dihydropyridine CCBs, amiodarone | |
| Propranolol (long-acting) | Initial: 80 mg PO once daily Usual: 320 mg PO once daily Maximum: 480 mg/day | Fatigue, bradycardia, reduced exercise capacity, headache, erectile dysfunction, vivid dreams; more prone to CNS effects (insomnia, depression) given higher lipid solubility | Additive bradycardia with digoxin, non-dihydropyridine CCBs, amiodarone; CYP2D6 inhibitors raise propranolol levels; raises rizatriptan levels | Use the long-acting (SR) formulation once daily; not currently linked in the Pharmasist Drug Database. |
| Timolol | Initial: 5 mg PO BID Usual: 20 mg PO BID Maximum: 30 mg PO BID | Fatigue, bradycardia, reduced exercise capacity, headache, erectile dysfunction, vivid dreams | Additive bradycardia with digoxin, non-dihydropyridine CCBs, amiodarone | Oral formulation not currently linked in the Pharmasist Drug Database (distinct from ophthalmic timolol). |
Beta-Blockers — Cardioselective (beta1-selective)
Preferred over non-selective agents when a beta-blocker is indicated, given fewer non-cardiac effects. Same tapering and heart-block cautions as non-selective agents.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Atenolol | Initial: 25 mg PO once daily Usual: 50 mg PO once daily Maximum: 100 mg/day, once daily or divided BID | Fatigue, bradycardia, reduced exercise capacity, headache, erectile dysfunction | Additive bradycardia with digoxin, non-dihydropyridine CCBs, amiodarone | Avoid in pregnancy — associated with fetal growth restriction, unlike other beta-blockers. |
| Bisoprolol | Initial: 5 mg PO once daily Usual: 10 mg PO once daily Maximum: 20 mg/day | Fatigue, bradycardia, reduced exercise capacity, headache | Additive bradycardia with digoxin, non-dihydropyridine CCBs, amiodarone | |
| Metoprolol | Initial: 50 mg/day Usual: 100-200 mg/day Maximum: 400 mg/day | Fatigue, bradycardia, reduced exercise capacity, headache | Additive bradycardia with digoxin, non-dihydropyridine CCBs, amiodarone; CYP2D6 inhibitors raise levels | Give regular-release formulations BID; sustained-release once daily. |
| Nebivolol | Initial: 5 mg PO once daily Usual: 10 mg PO once daily Maximum: 20 mg/day | Fatigue, bradycardia, reduced exercise capacity, headache; added vasodilating activity | Additive bradycardia with digoxin, non-dihydropyridine CCBs, amiodarone; CYP2D6 inhibitors raise levels |
Beta-Blockers — With Intrinsic Sympathomimetic Activity (ISA)
ISA agents cause less resting bradycardia than agents without ISA; a minor, infrequently used subgroup.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Pindolol | Initial: 5 mg PO BID Usual: 15 mg PO BID Maximum: 60 mg/day | Fatigue, bradycardia, reduced exercise capacity, headache — less pronounced bradycardia than non-ISA agents | Additive bradycardia with digoxin, non-dihydropyridine CCBs, amiodarone | Not currently linked in the Pharmasist Drug Database. |
| Acebutolol | Initial: 100 mg/day Usual: 400 mg/day Maximum: 800 mg/day, once daily or divided BID | Fatigue, bradycardia, reduced exercise capacity, headache — less pronounced bradycardia than non-ISA agents | Additive bradycardia with digoxin, non-dihydropyridine CCBs, amiodarone | Not currently linked in the Pharmasist Drug Database. |
Combined Alpha1/Beta-Blocker
A reasonable compelling-indication choice when both alpha- and beta-blockade are wanted, and one of the preferred agents in pregnancy.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Labetalol | Initial: 50 mg PO BID Usual: 200 mg PO BID Maximum: 1200 mg/day (up to 2400 mg/day used in resistant hypertension) | Dizziness (especially postural), fatigue, nausea, nasal stuffiness, scalp tingling | Cimetidine increases bioavailability; additive hypotension with nitroglycerin/general anesthetics; additive bradycardia with non-dihydropyridine CCBs | One of the preferred oral and IV agents for hypertension in pregnancy. |
Calcium Channel Blockers — Dihydropyridine
Older patients with isolated systolic hypertension respond particularly well to this class. Never use a short-acting dihydropyridine (immediate-release nifedipine) for chronic hypertension.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Amlodipine | Initial: 2.5 mg PO once daily Maximum: 10 mg PO once daily | Ankle edema, flushing, headache, palpitations | CYP3A4 substrate — strong inhibitors (azole antifungals, protease inhibitors, macrolides, quinidine) raise levels; grapefruit juice may raise levels | |
| Felodipine (extended-release) | Initial: 2.5 mg PO once daily Usual: 10 mg PO once daily Maximum: 20 mg/day | Ankle edema, flushing, headache, palpitations | Same CYP3A4 profile as amlodipine | Grapefruit juice causes marked elevation in felodipine levels and adverse effects — avoid. |
| Nifedipine (extended-release) | Initial: 30 mg PO once daily Usual: 60 mg PO once daily Maximum: 120 mg/day | Ankle edema, flushing, headache, palpitations | Same CYP3A4 profile as amlodipine | Do not use a short-acting formulation for essential hypertension. The extended-release formulation is also a preferred agent for chronic hypertension in pregnancy, and immediate-release nifedipine is used for acute severe hypertension in pregnancy under specialist direction. |
Calcium Channel Blockers — Non-Dihydropyridine
Avoid combining with a beta-blocker without close monitoring given additive bradycardia/AV-block risk; avoid in significant heart failure.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Diltiazem | Initial: 120 mg/day Usual: 240-360 mg/day Maximum: 360 mg/day | Headache, dizziness, bradycardia, heart block, new-onset or worsening heart failure | CYP3A4 substrate and inhibitor — raises levels of carbamazepine, cyclosporine, lovastatin, simvastatin; rifampin induces metabolism; additive negative chronotropic effect with amiodarone/beta-blockers/digoxin | Caution in heart failure or 2nd-/3rd-degree heart block without a pacemaker. Give the CD/XC formulation once daily; the SR formulation divided BID. |
| Verapamil | Immediate-release: 80 mg PO TID initially, up to 160 mg PO TID Sustained-release, initial: 180 mg/day Sustained-release, usual: 180-480 mg/day Sustained-release, maximum: 480 mg/day | Headache, dizziness, bradycardia, heart block, constipation, new-onset or worsening heart failure | Same CYP3A4 profile as diltiazem; significantly raises digoxin levels within about 1 week of starting — check digoxin levels and watch for toxicity | Caution in heart failure or 2nd-/3rd-degree heart block without a pacemaker. |
Centrally Acting Agents
Not for initial therapy; reserved for resistant hypertension or specific situations.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Clonidine | Initial: 0.1 mg PO BID Usual: 0.3 mg PO BID | Sedation, dry mouth, orthostatic hypotension, dizziness | Potential for bradycardia/AV block with beta-blockers, CCBs, digoxin; tricyclic antidepressants may reduce hypotensive effect | Not for initial therapy. Never stop abruptly — taper the dose over at least 2-4 days to avoid rebound hypertension. |
| Methyldopa | Initial: 500 mg/day Usual: 2000 mg/day Maximum: 3000 mg/day, divided BID-TID | Drowsiness, dry mouth, nasal congestion, depression, orthostatic hypotension, sexual dysfunction, sodium/water retention; positive Coombs test is common but usually not clinically important; rare drug fever or hepatic reaction | Iron salts reduce absorption (separate dosing); additive hypotension with levodopa; may increase lithium adverse effects without raising lithium levels | One of the acceptable agents for chronic hypertension in pregnancy, though less potent and more side-effect-prone than labetalol or extended-release nifedipine. |
Potassium-Sparing Diuretics
Not for initial monotherapy; used as add-on therapy, particularly for resistant hypertension or to offset thiazide-induced hypokalemia.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Amiloride | Initial: 5 mg PO once daily Usual: 10 mg PO once daily | Hyperkalemia, muscle cramps, headache, GI symptoms | Avoid combining with NSAIDs, ACE inhibitors, ARBs, or potassium supplements — risk of severe hyperkalemia | Not for initial therapy. Caution in significant renal impairment. |
| Spironolactone | Initial: 25 mg PO once daily Usual: 100 mg PO once daily | Hyperkalemia, gynecomastia and other androgen-related effects, breast tenderness, GI symptoms | Avoid combining with NSAIDs, ACE inhibitors, ARBs, or potassium supplements — risk of severe hyperkalemia | Preferred add-on for resistant hypertension once an ACE inhibitor/ARB, thiazide-like diuretic, and dihydropyridine CCB have not reached target. Not for initial therapy. Contraindicated in pregnancy. |
Thiazide / Thiazide-Like Diuretics
First-line only as part of a single-pill combination with an ACE inhibitor or ARB, or as one of 2 separate pills. Ineffective once creatinine clearance falls below 30-40 mL/min, where a loop diuretic is preferred instead.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Hydrochlorothiazide | Initial: 12.5 mg PO once daily Usual: 25 mg PO once daily | Hypokalemia, hyponatremia, hyperuricemia, hyperglycemia, hyperlipidemia, hypotension, muscle cramps, photosensitivity; rare blood dyscrasias/allergic reactions (potential cross-sensitivity with other sulfonamide derivatives) | Reduces lithium excretion (monitor levels); NSAIDs reduce hypotensive efficacy; diuretic-induced hypokalemia increases digoxin toxicity risk; may reduce efficacy of antihyperglycemic agents | Particularly effective in isolated systolic hypertension. Monitor creatinine and potassium. |
| Chlorthalidone | Initial: 12.5 mg PO once daily Usual: 12.5-25 mg PO once daily | Same as hydrochlorothiazide | Same as hydrochlorothiazide | Long-acting thiazide-like diuretic, preferred over hydrochlorothiazide when 2 separate pills are used instead of a single-pill combination. Lowest available tablet strength is 50 mg; a tablet splitter can be used to derive a 12.5 mg dose. |
| Indapamide | Initial: 1.25 mg PO once daily Usual: 2.5 mg PO once daily | Same as hydrochlorothiazide | Same as hydrochlorothiazide | Long-acting thiazide-like diuretic. |
| Metolazone | Initial: 2.5 mg PO once daily Usual: 5 mg PO once daily Maximum: 10 mg/day | Same as hydrochlorothiazide | Same as hydrochlorothiazide | Remains effective in moderate-to-severe renal impairment, unlike hydrochlorothiazide, chlorthalidone, or indapamide. |
Single-Pill Combinations — ACE Inhibitor / Calcium Channel Blocker
Contraindicated in pregnancy.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Perindopril / Amlodipine | Dosing: 3.5/2.5 mg PO once daily initially, up to 7/5 mg PO once daily | Combined dry cough, hyperkalemia, ankle edema, hypotension | Combined ACE inhibitor/CCB interaction profile — see individual components |
Single-Pill Combinations — ACE Inhibitor / Diuretic
First-line option when a single-pill combination is preferred over 2 separate pills. Contraindicated in pregnancy. Ineffective at creatinine clearance under 30-40 mL/min.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Cilazapril / Hydrochlorothiazide | Dosing: 5/12.5 mg PO once daily | Combined dry cough, electrolyte disturbance, hypotension, renal effects | Monitor potassium with potassium-sparing agents/supplements; NSAIDs reduce efficacy and increase renal-dysfunction risk | |
| Enalapril / Hydrochlorothiazide | Dosing: 5/12.5 mg or 10/25 mg PO once daily | Combined dry cough, electrolyte disturbance, hypotension, renal effects | Same as other ACE inhibitor/diuretic combinations | |
| Lisinopril / Hydrochlorothiazide | Dosing: 10/12.5 mg, 20/12.5 mg, or 20/25 mg PO once daily | Combined dry cough, electrolyte disturbance, hypotension, renal effects | Same as other ACE inhibitor/diuretic combinations | |
| Perindopril / Indapamide | Dosing: 2/0.625 mg, 4/1.25 mg, or 8/2.5 mg PO once daily | Combined dry cough, electrolyte disturbance, hypotension, renal effects | Same as other ACE inhibitor/diuretic combinations | |
| Quinapril / Hydrochlorothiazide | Dosing: 10/12.5 mg, 20/12.5 mg, or 20/25 mg PO once daily | Combined dry cough, electrolyte disturbance, hypotension, renal effects | Same as other ACE inhibitor/diuretic combinations | |
| Ramipril / Hydrochlorothiazide | Dosing: 2.5/12.5 mg, 5/12.5 mg, 10/12.5 mg, 5/25 mg, or 10/25 mg PO once daily | Combined dry cough, electrolyte disturbance, hypotension, renal effects | Same as other ACE inhibitor/diuretic combinations |
Single-Pill Combinations — ARB / Diuretic
The preferred first-line single-pill combination class for most adults starting therapy without a compelling comorbid indication. Contraindicated in pregnancy.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Azilsartan / Chlorthalidone | Dosing: 40/12.5 mg, 40/25 mg, or 80/12.5 mg PO once daily | Combined hyperkalemia, electrolyte disturbance, hyperuricemia, hypotension | Monitor potassium with potassium-sparing agents/supplements; NSAIDs reduce efficacy | |
| Candesartan / Hydrochlorothiazide | Dosing: 16/12.5 mg PO once daily | Combined hyperkalemia, electrolyte disturbance, hypotension | Same as other ARB/diuretic combinations | |
| Irbesartan / Hydrochlorothiazide | Dosing: 150/12.5 mg or 300/12.5 mg PO once daily | Combined hyperkalemia, electrolyte disturbance, hypotension | Same as other ARB/diuretic combinations | Preferred initial single-pill combination in the current Hypertension Canada algorithm — start at half the standard-strength tablet and double after 4-6 weeks if not at target. |
| Losartan / Hydrochlorothiazide | Dosing: 50/12.5 mg or 100/25 mg PO once daily | Combined hyperkalemia, electrolyte disturbance, hypotension | Same as other ARB/diuretic combinations | |
| Olmesartan / Hydrochlorothiazide | Dosing: 20/12.5 mg, 40/12.5 mg, or 40/25 mg PO once daily | Combined hyperkalemia, electrolyte disturbance, hypotension | Same as other ARB/diuretic combinations | |
| Telmisartan / Hydrochlorothiazide | Dosing: 80/12.5 mg or 80/25 mg PO once daily | Combined hyperkalemia, electrolyte disturbance, hypotension | Same as other ARB/diuretic combinations | |
| Valsartan / Hydrochlorothiazide | Dosing: 80/12.5 mg, 160/12.5 mg, or 160/25 mg PO once daily | Combined hyperkalemia, electrolyte disturbance, hypotension | Same as other ARB/diuretic combinations |
Single-Pill Combinations — Beta-Blocker / Diuretic
Only used when a beta-blocker is separately indicated for a compelling reason.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Atenolol / Chlorthalidone | Dosing: 50/25 mg or 100/25 mg PO once daily | Combined beta-blocker and diuretic effects (bradycardia, hypokalemia) | Same interaction profile as the individual components | |
| Pindolol / Hydrochlorothiazide | Dosing: 10/25 mg or 10/50 mg PO once daily | Combined beta-blocker (ISA) and diuretic effects | Same interaction profile as the individual components | Not currently linked in the Pharmasist Drug Database. |
Single-Pill Combination — Calcium Channel Blocker / ARB
Contraindicated in pregnancy.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Amlodipine / Telmisartan | Dosing: 5/40 mg, 5/80 mg, 10/40 mg, or 10/80 mg PO once daily | Combined ankle edema and hyperkalemia | Same interaction profile as the individual components |
Calcium Channel Blocker / HMG-CoA Reductase Inhibitor Combination
For a patient with both hypertension and an indication for a statin — a convenience combination rather than a hypertension-specific interaction advantage.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Amlodipine / Atorvastatin | Dosing: Amlodipine 5 or 10 mg with atorvastatin 10, 20, 40, or 80 mg PO once daily | Combined ankle edema and myalgia | Both components are CYP3A4 substrates |
Diuretic / Diuretic Combinations
Combine a thiazide with a potassium-sparing diuretic specifically to reduce thiazide-induced hypokalemia.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Hydrochlorothiazide / Amiloride | Dosing: Half of a 50/5 mg tablet PO once daily | Same as hydrochlorothiazide, with a lower hypokalemia risk than a thiazide alone | Same interaction profile as the individual components | |
| Hydrochlorothiazide / Triamterene | Initial: Half of a 25/50 mg tablet PO once daily Usual: 1 tablet PO once daily | Same as hydrochlorothiazide, with a lower hypokalemia risk than a thiazide alone | Same interaction profile as the individual components | |
| Hydrochlorothiazide / Spironolactone | Initial: Half of a 25/25 mg tablet PO once daily Usual: 1 tablet PO once daily | Same as hydrochlorothiazide, plus gynecomastia/breast tenderness, with a lower hypokalemia risk than a thiazide alone | Same interaction profile as the individual components |
References
- Hypertension Canada guideline for the diagnosis and treatment of hypertension in adults in primary care — Hypertension Canada / CMAJ (Goupil R, Tsuyuki RT, Santesso N, et al.). CMAJ 2025;197(20):E549-E564
- Hypertension Canada's 2020 evidence review and guidelines for the management of resistant hypertension — Canadian Journal of Cardiology (Hiremath S, Sapir-Pichhadze R, Nakhla M, et al.). Can J Cardiol 2020;36(5):625-634
- Guideline No. 426: Hypertensive Disorders of Pregnancy: Diagnosis, Prediction, Prevention, and Management — Journal of Obstetrics and Gynaecology Canada (Magee LA, Smith GN, Bloch C, et al.). J Obstet Gynaecol Can 2022;44(5):547-571
- Aspirin versus placebo in pregnancies at high risk for preterm preeclampsia — New England Journal of Medicine (Rolnik DL, Wright D, Poon LC, et al., ASPRE trial). N Engl J Med 2017;377(7):613-622
- 2023 ESH Guidelines for the management of arterial hypertension — Journal of Hypertension, European Society of Hypertension Task Force. J Hypertens 2023;41(12):1874-2071
- Cardiovascular outcomes in adults with hypertension with evening versus morning dosing of usual antihypertensives in the UK (TIME study): a prospective, randomised, open-label, blinded-endpoint clinical trial — The Lancet (Mackenzie IS, Rogers A, Poulter NR, et al.). Lancet 2022;400(10361):1417-1425
Professional reference only. Apply clinical judgment and verify patient-specific decisions against current authoritative guidance and product information.