Heavy Menstrual Bleeding
Clinical Snapshot
Heavy menstrual bleeding (HMB) — the term that has replaced "menorrhagia" — is abnormal uterine bleeding (AUB) with excessive menstrual blood flow that interferes with a patient's quality of life, and it commonly causes or coexists with iron-deficiency anemia.[1] It can occur with an otherwise regular, predictable cycle or alongside irregular, unpredictable bleeding — the pattern itself is a clue to the underlying cause, since regular-cycle HMB more often reflects a structural or local endometrial cause while irregular bleeding more often reflects ovulatory dysfunction. The FIGO PALM-COEIN system is the standard framework for classifying the underlying cause into structural (Polyp, Adenomyosis, Leiomyoma, Malignancy/hyperplasia) versus non-structural (Coagulopathy, Ovulatory dysfunction, Endometrial, Iatrogenic, Not-otherwise-classified) categories, and this classification directly determines the workup and treatment pathway.[2] Pharmacologic therapy — non-hormonal (tranexamic acid, NSAIDs) or hormonal (most effectively the levonorgestrel-releasing intrauterine system) — is first-line for most patients; surgical options are reserved for patients who do not desire future fertility, decline medical therapy, or fail it.
Recognize the Condition
HMB is a clinical diagnosis built on history rather than a specific physical sign. Patients describe one or more of: prolonged menses (bleeding lasting longer than 7 days), soaking through a pad or tampon in less than 1-2 hours on the heaviest days, needing to use double protection (pad plus tampon) to control flow, passing clots larger than about 2.5 cm (roughly the size of a quarter), needing to change protection overnight, or restricting work, school, exercise, or social activities because of bleeding volume or the fear of an accident. Ask directly about the impact on daily activities and quality of life — this is now the clinically preferred way to gauge severity, rather than trying to estimate a precise blood-loss volume, since patient-perceived impact and measured blood loss do not always track together.
Symptoms of the resulting iron-deficiency anemia — fatigue, exertional dyspnea, palpitations, lightheadedness, pallor, pica, or restless legs — are common presenting complaints in their own right and should prompt the same HMB workup even when the patient has not framed their visit as being about their periods.
Distinguish the bleeding pattern: regular, cyclic HMB (predictable timing, just heavier or longer than usual) points toward a structural or local endometrial cause and is generally ovulatory; irregular, unpredictable HMB (variable timing and/or volume) points toward ovulatory dysfunction (adolescence, perimenopause, PCOS, thyroid disease, hyperprolactinemia, eating disorder) or an iatrogenic cause. This distinction guides both the initial workup and the choice of first-line hormonal therapy if one is used.
Risk Factors
- Adolescence — an immature hypothalamic-pituitary-ovarian axis produces anovulatory cycles, particularly in the first year after menarche.
- Perimenopause — anovulatory cycles become common again as ovarian function declines.
- Polycystic ovary syndrome and other causes of chronic anovulation.
- Hypothyroidism or hyperthyroidism.
- Hyperprolactinemia.
- Obesity — associated with both anovulation and unopposed estrogen exposure.
- Uterine fibroids (leiomyomas), endometrial or endocervical polyps, and adenomyosis.
- A bleeding disorder (most importantly von Willebrand disease) — especially relevant in adolescents with HMB since menarche, or anyone with a personal or family history of easy bruising, epistaxis, or heavy bleeding after dental extraction or childbirth.
- Anticoagulant therapy.
- An intrauterine device (copper IUDs increase menstrual blood loss; hormonal iatrogenic causes can also produce unscheduled bleeding).
- Risk factors for endometrial hyperplasia or malignancy: age over 40, BMI 35 or higher, diabetes, hypertension, unopposed estrogen exposure, nulliparity, PCOS, and a family history of endometrial cancer.
- Liver or renal disease affecting hormone metabolism or clotting factor synthesis/clearance.
Red Flags & Refer
Heavy menstrual bleeding is usually not itself an emergency, but escalate immediately for any of the following:
- Signs of hemodynamic instability from acute heavy bleeding — tachycardia, hypotension, orthostatic dizziness or syncope, or bleeding soaking through a pad or tampon every hour for several consecutive hours — needs emergency assessment and stabilization, not a routine outpatient visit.
- Symptomatic anemia — significant fatigue, dyspnea on exertion, chest pain, or marked pallor — warrants an urgent hemoglobin check and, if severe, same-day referral rather than waiting for a scheduled workup.
- Postmenopausal bleeding always requires prompt gynecologic investigation and must never be presumptively treated as heavy menstrual bleeding — any bleeding after menopause is endometrial cancer until proven otherwise.
- Intermenstrual or postcoital bleeding, or new pelvic pain or pressure, suggests a structural cause (polyp, fibroid, malignancy) and needs investigation before — or alongside — starting symptomatic treatment.
- Suspected pregnancy-related bleeding (possible ectopic pregnancy, threatened or incomplete miscarriage) must be excluded before any bleeding is treated as heavy menstrual bleeding, since this chapter's therapies do not apply to pregnancy-related bleeding.
- An adolescent with heavy bleeding since menarche, or anyone with a personal or family history of a bleeding disorder, unexplained bruising, or heavy bleeding after a dental extraction or childbirth, needs coagulation screening for von Willebrand disease before treatment is finalized.
- A rapidly enlarging pelvic mass, or bleeding that persists despite an adequate trial of appropriate therapy, warrants gynecologic referral to exclude malignancy.
Assessment & Diagnosis
History
Characterize the bleeding pattern (regular/cyclic versus irregular/unpredictable), duration, and impact on quality of life; ask specifically about flooding, clot size, pad/tampon changes, and overnight protection. Take a personal and family bleeding-disorder history, current medications (anticoagulants, hormonal therapy, an IUD), and screen for symptoms of thyroid disease, hyperprolactinemia, and PCOS.
Examination
Visual inspection of the vulva, vagina, and cervix; speculum and bimanual examination to assess for a visible lesion, cervical friability, uterine size/contour, and adnexal masses; general examination for pallor, thyromegaly, hirsutism/acne (PCOS), or bruising/petechiae suggesting a bleeding disorder.
Initial investigations
- Pregnancy test in anyone of reproductive potential.
- CBC to assess for anemia.
- Serum ferritin when anemia is confirmed, or when iron-deficiency symptoms are present even without frank anemia — iron-deficiency anemia is a near-universal comorbidity of HMB and needs its own directed treatment (see Treatment Targets and Special Populations).
- Thyroid function testing if the history or examination suggests thyroid disease — not a routine test in every HMB workup.
- Coagulation screening (including von Willebrand studies) for adolescents with HMB since menarche, or anyone with a personal/family bleeding-disorder history — this population has a meaningfully higher rate of an underlying bleeding disorder than adult HMB overall.
- Pelvic ultrasound (transvaginal preferred where feasible) as the first-line imaging test for structural causes.
- Endometrial biopsy in patients over 40 years of age, and in younger patients with risk factors for endometrial carcinoma (BMI 35 or higher, diabetes, hypertension, exposure to unopposed estrogen, nulliparity, PCOS, or a family history of endometrial cancer).
- MRI and/or hysteroscopy as second-line imaging when ultrasound is inconclusive or a structural lesion needs further characterization before treatment planning (e.g., fibroid mapping before myomectomy).
Laboratory testing for female sex hormones (FSH, LH, estradiol) is not routinely indicated in the initial workup of HMB with otherwise-regular ovulatory cycles.[1]
FIGO PALM-COEIN classification of underlying causes
Structural causes (PALM) — visible on imaging/biopsy
- Polyp — endometrial or endocervical.
- Adenomyosis — endometrial glands/stroma within the myometrium.
- Leiomyoma — fibroids, submucosal or other location.
- Malignancy and hyperplasia.
Non-structural / functional causes (COEIN) — not visible on imaging alone
- Coagulopathy — congenital or acquired.
- Ovulatory dysfunction — adolescence, PCOS, perimenopause, hyper/hypothyroidism, eating disorder, hyperprolactinemia.
- Endometrial — dysregulation of local endometrial hemostasis, a diagnosis of exclusion in a patient with regular ovulatory cycles and no other identified cause.
- Iatrogenic — hormonal therapy, an intrauterine device, or anticoagulants.
- Not otherwise classified — arteriovenous malformation, uterine scar (e.g., cesarean section niche).
Any treatment approach requires this search for uterine structural abnormalities alongside hormonal and hematologic causes; when a specific underlying cause is identified, directed therapy toward that cause should be added to symptomatic HMB treatment.[1]
Treatment Targets
- Reduce menstrual blood loss to a volume that no longer interferes with the patient's physical, emotional, social, or material quality of life.
- Identify and correct iron-deficiency anemia — treat this directly with iron repletion, not merely by reducing bleeding volume and waiting for it to resolve on its own.
- Identify any specific underlying structural or functional cause (PALM-COEIN) and add directed therapy toward that cause when one is found.
- Provide effective contraception concurrently when the patient desires it, since several of the most effective HMB therapies are also highly effective contraceptives.
- Preserve fertility for patients who desire future pregnancy when choosing among otherwise-comparable options.
- Avoid unnecessary surgery when medical therapy can achieve adequate control and the patient prefers a uterine-preserving option.
Choose Initial Treatment
Contraception desired, no contraindication, and a normal uterine cavity
1st line the levonorgestrel-releasing intrauterine system (Mirena) — the single most effective medical treatment for HMB and simultaneously highly effective, long-acting, reversible contraception; offer it first in both sexually active and non-sexually-active patients (including adolescents, with individualized counselling) when there is no contraindication and the cavity is not significantly distorted.[3]
Contraception desired but the LNG-IUS is declined or unsuitable
Alternative hormonal option a combined hormonal contraceptive (pill, patch, or ring), used cyclically or continuously — particularly favour this option when irregular cycle timing coexists with HMB, since it also regulates cycle predictability.
No contraception desired, and no hormonal therapy preferred
1st-line non-hormonal option tranexamic acid and/or an NSAID (mefenamic acid or naproxen), taken only on heavy-flow days — combine both classes if either alone gives an inadequate response. Favour an NSAID specifically, or add one, when dysmenorrhea coexists with HMB, since NSAIDs treat both.
Contraception not needed, but an oral hormonal option is preferred
Alternative extended-cycle oral progestin (norethindrone acetate, medroxyprogesterone acetate, or micronized progesterone) taken for at least 21 days per month — this is less effective than the LNG-IUS or a combined hormonal contraceptive for cycle control, so reserve it for patients who specifically prefer or require an oral, non-estrogen option. A luteal-phase-only regimen (10-14 days per month) is less effective and is generally not recommended.
Refractory to first-line therapy, or bridging to surgery
Special situation a short-term (generally 6 months or less) course of a GnRH agonist (goserelin, leuprolide, or nafarelin), with estrogen-progestogen add-back therapy if treatment continues beyond 6 months, particularly to shrink fibroid volume before planned surgery or when other options have failed or are contraindicated.
Acute severe bleeding
Special situation manage as its own pathway (see Clinical Decision Algorithm and Drug Tables) — hemodynamic stabilization first, then high-dose hormonal therapy or tranexamic acid, escalating to emergency surgical management if the patient is unstable or fails to respond.
Non-Pharmacologic Treatment
- Have the patient track bleeding using a simple pad/tampon diary (product type, number used, degree of soaking, clot size, and days of flow) — this both quantifies severity at baseline and gives an objective way to judge whether treatment is working.
- Counsel on the correct timing of on-demand therapy: tranexamic acid and NSAIDs are taken only during the days of heavy flow (starting the day before or the first day of bleeding and continuing for 3-5 days or until flow subsides), not continuously through the cycle.
- Before LNG-IUS insertion, counsel explicitly that irregular spotting is expected for the first 3 to 6 months and does not mean the device has failed — advise waiting at least 6 cycles before judging the treatment's effect on bleeding volume.
- Iron-rich dietary counselling for patients with or at risk of iron-deficiency anemia, alongside — not instead of — oral iron supplementation when indicated.
- Encourage activity modification and realistic planning (e.g., having supplies on hand, layered clothing) on anticipated heavy-flow days while definitive treatment takes effect.
- Advise when to seek urgent care (see Red Flags & Refer) rather than waiting for a scheduled follow-up.
Surgical and procedural options are the non-pharmacologic endpoint for patients who have completed childbearing, decline medical therapy, or fail it. Endometrial ablation is a minimally invasive, uterine-preserving procedure (laser, electrocautery, resection, or heat-based) that destroys the endometrial lining and is highly effective at reducing bleeding, though a meaningful proportion of patients eventually need further intervention.[1] Hysterectomy is the definitive treatment, with the highest rate of patient satisfaction of any option, and is increasingly performed through minimally invasive (vaginal, laparoscopic, or robotic) approaches. For patients who wish to preserve fertility with a structural fibroid-related cause, uterine artery embolization or myomectomy are alternatives to hysterectomy, and hysteroscopic resection is definitive treatment for small submucosal fibroids and endometrial polyps. Because this chapter is pharmacotherapy-focused, procedure selection, technique, and perioperative management are gynecologic surgical decisions outside its scope — the role of the pharmacist is to recognize when medical therapy has been adequately trialled and a surgical referral is the appropriate next step (see Treatment Failure & Next Step).
Special Populations
Pregnancy
Bleeding in pregnancy is, by definition, not heavy menstrual bleeding — pregnancy must always be excluded first, and pregnancy-related bleeding (threatened/incomplete miscarriage, ectopic pregnancy) is managed through the appropriate obstetric pathway, not this chapter's therapies. NSAIDs, GnRH agonists, danazol, elagolix, and combined hormonal contraceptives are not used in pregnancy. Tranexamic acid crosses the placenta; a risk-benefit discussion is required if genuinely needed for a separate indication during pregnancy, since available data have not clearly established or excluded a fetal risk with early-pregnancy exposure.[4]
Breastfeeding
NSAIDs (standard doses) and progestin-only methods (LNG-IUS, oral progestins, DMPA) are compatible with breastfeeding; combined hormonal contraceptives are generally deferred until breastfeeding is well established given a theoretical effect on milk supply. Tranexamic acid passes into breast milk at only a small fraction of the maternal serum concentration, and current lactation-safety data do not show adverse effects on the breastfed infant — it is generally considered compatible with breastfeeding when clinically needed.
Adolescents
Screen for a bleeding disorder (especially von Willebrand disease) in any adolescent with HMB since menarche — this population has a meaningfully higher rate of an underlying coagulopathy than the general HMB population. Anovulatory cycles related to an immature hypothalamic-pituitary-ovarian axis are common and often normalize over the first year or two after menarche. The LNG-IUS and combined hormonal contraceptives remain first-line options in adolescents, sexually active or not, with individualized counselling on insertion/use. Tranexamic acid for the menorrhagia indication specifically is not authorized by Health Canada for patients under 18 years of age — clinical experience in this population was not available at the time of licensing — so weigh this against alternatives (NSAID, hormonal therapy) with an established evidence base in adolescents, and treat any such use as an individualized, specialist-informed decision rather than routine practice.[4]
Perimenopausal and older reproductive-age patients
Endometrial pathology risk rises with age — apply a lower threshold for endometrial biopsy (age over 40, per Assessment & Diagnosis) and reassess the diagnosis rather than reflexively escalating the same HMB therapy if the bleeding pattern changes.
Renal impairment
Tranexamic acid requires dose reduction in renal insufficiency because blood levels rise with reduced clearance — see Drug Tables for the specific serum-creatinine-based adjustment. NSAIDs should generally be avoided in significant renal impairment.
Bleeding disorders / anticoagulant therapy
NSAIDs are contraindicated in patients with a known bleeding disorder. Tranexamic acid can be particularly useful in this population given its antifibrinolytic mechanism, but coordinate with hematology, since patients with a history or risk of thrombosis are themselves a contraindication to tranexamic acid — these are two different bleeding-related populations that need individualized, not interchangeable, reasoning.
Additional caution before starting tranexamic acid
Patients who are obese and diabetic, have PCOS or a first-degree relative with endometrial cancer, or are on unopposed estrogen or tamoxifen should discuss initiation with their prescriber first, given these patients' independently elevated endometrial-pathology risk profile.[4]
Monitoring & Follow-Up
Reassess bleeding severity and quality-of-life impact at each visit using the same pad/tampon-diary approach established at baseline, and recheck CBC (and ferritin if it was low) to confirm anemia is resolving on the chosen regimen plus iron repletion. For the LNG-IUS specifically, expect and counsel through irregular spotting during the first 3-6 months, and do not judge treatment effect before at least 6 cycles have passed. For tranexamic acid, the Canadian product monograph directs patients to consult their prescriber if bleeding is not reduced after 3 menstrual cycles of correctly-used therapy, and to switch to an alternative treatment if it remains inadequately controlled.[4] Reassess ongoing need for and contraindications to hormonal therapy at least annually. Any new red-flag symptom — intermenstrual/postcoital bleeding, postmenopausal bleeding, or a new pelvic mass — should prompt re-investigation rather than simply adjusting the current HMB regimen. Patients on a GnRH agonist beyond 6 months need bone density monitoring; patients on danazol need periodic lipid and liver function monitoring given its adverse-effect profile; patients on tranexamic acid for several weeks or longer should have their vision monitored (sharpness, colour vision) given rare reports of visual disturbance, and the drug should be stopped if this occurs.[4]
Common Errors to Avoid
- Treating postmenopausal bleeding empirically as HMB without investigation — it is endometrial cancer until proven otherwise.
- Missing coagulation screening in an adolescent with HMB since menarche.
- Prescribing an NSAID to a patient with a known bleeding disorder, active pelvic inflammatory disease, or significant renal impairment.
- Under-recognizing iron-deficiency anemia as "just heavy periods" — check CBC/ferritin and start iron repletion directly rather than assuming it will resolve once bleeding is controlled.
- Judging the LNG-IUS a failure before 3-6 cycles, when irregular spotting is the expected early pattern.
- Combining tranexamic acid with a combined hormonal contraceptive without weighing additional VTE risk factors (obesity, smoking, immobility).[4]
- Continuing GnRH agonist monotherapy beyond 6 months without adding estrogen-progestogen add-back therapy for bone protection.
- Recommending or continuing ulipristal acetate (Fibristal) for fibroid-related HMB — it was voluntarily withdrawn from the Canadian market in 2020 for serious liver injury risk and remains unavailable; do not confuse it with the differently-dosed, differently-indicated single-dose emergency contraceptive product that shares the same molecule.[5]
- Skipping endometrial biopsy in a patient under 40 who otherwise has clear risk factors for endometrial pathology.
- Starting a patient with irregular menstrual bleeding on tranexamic acid before the cause of the irregularity has been established, per Health Canada's own product-labelling caution.[4]
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.
Antifibrinolytics
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Tranexamic acid | Adults, chronic/cyclical HMB: 1 g (2 x 500 mg tablets) PO 3-4 times daily for several days, starting once heavy bleeding has begun Adults, acute severe bleeding: Oral 1.3 g TID, or IV 10 mg/kg every 6-8 hours Renal impairment, SCr 120-250 micromol/L: 15 mg/kg PO or 10 mg/kg IV twice daily Renal impairment, SCr 250-500 micromol/L: 15 mg/kg PO or 10 mg/kg IV once every 24 hours Renal impairment, SCr 500 micromol/L or more: Same dose once every 48 hours Adolescents/children under 18 years: Not authorized by Health Canada for the menorrhagia indication in this age group -- clinical experience is not available; treat as an individualized, specialist-informed decision rather than routine practice | Nausea, vomiting, diarrhea; rare dizziness, hypotension, or visual disturbance with prolonged use | Avoid with other prothrombotic products; additive VTE risk with combined hormonal contraceptives -- advise a nonhormonal contraceptive alternative if both are genuinely needed | Contraindicated with a history/risk of thrombosis (unless anticoagulated), active thromboembolic disease, subarachnoid hemorrhage, acquired disturbance of colour vision, or hematuria of renal origin. Do not start until the cause of irregular bleeding has been established. Consult prescriber/switch therapy if bleeding is not reduced after 3 cycles. |
NSAIDs
Start the day before or on the first day of heavy flow and continue 3-5 days or until bleeding subsides. Contraindications common to this class: hypersensitivity to ASA/NSAIDs, active pelvic inflammatory disease, significant renal impairment, or a bleeding disorder.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Mefenamic acid | Adults: 500 mg PO TID during heavy flow Adolescents (post-menarche): Same as adult dosing | Dyspepsia, nausea, headache, dizziness | SSRIs may increase GI bleeding risk when combined with an NSAID | |
| Naproxen | Adults: 500 mg PO first dose, then 250 mg every 6-8 hours during menses Adolescents (post-menarche): Same as adult dosing | Dyspepsia, nausea/vomiting, rash, dizziness, headache | SSRIs may increase GI bleeding risk when combined with an NSAID | |
| Ibuprofen | Adults: 400 mg PO every 6 hours with food, maximum 2400 mg/day Adolescents (post-menarche): Same as adult dosing | Dyspepsia, nausea/vomiting, rash, dizziness, headache | SSRIs may increase GI bleeding risk when combined with an NSAID |
Oral and injectable progestins
Normalize the endometrial response to estrogen and reduce breakthrough bleeding; continuous use prevents menstrual flow entirely. Generally less effective than the LNG-IUS or a combined hormonal contraceptive for cycle control.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Medroxyprogesterone acetate, oral (extended-cycle) | Extended-cycle: 10 mg PO daily for at least 21 days per month (cycle days 5-26) | Bloating, irritability, weight gain, mood changes | None significant | A luteal-phase-only regimen (10-14 days/month) is less effective and is not recommended. |
| Medroxyprogesterone acetate, oral (acute bleeding taper) | Acute severe bleeding: 20 mg PO TID for 7 days, then 20 mg PO daily for 21 days | Bloating, irritability, weight gain, mood changes | None significant | Bleeding cessation is expected within about 3 days; transition to maintenance therapy once controlled. |
| Medroxyprogesterone acetate, injectable (DMPA) | Adults: 150 mg intramuscular (or 104 mg subcutaneous) every 12-14 weeks | Bloating, irritability, weight gain, mood changes, delayed return to fertility after stopping | None significant | Long used to induce amenorrhea; also provides contraception. |
| Norethindrone acetate, oral (extended-cycle) | Extended-cycle: 5 mg PO daily for at least 21 days per month | Bloating, irritability, weight gain, mood changes | None significant | |
| Micronized progesterone, oral (extended-cycle) | Extended-cycle: 300 mg PO at bedtime for at least 21 days per month | Bloating, irritability, weight gain, mood changes; drowsiness | None significant | Generally better-tolerated than medroxyprogesterone acetate. Generic capsules contain peanut oil -- avoid with peanut allergy; brand-name capsules use sunflower oil but contain soy lecithin -- caution with soy allergy. |
Levonorgestrel-releasing intrauterine system
The most effective medical treatment for HMB, and simultaneously highly effective long-acting reversible contraception.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Levonorgestrel-releasing intrauterine system | Treatment of idiopathic HMB: One 52 mg system inserted intrauterine, effective up to 5 years for this indication Contraception (if continued beyond the HMB-approved duration): Same system remains approved for contraception alone up to 8 years | Irregular spotting (especially first 3-6 months), amenorrhea over time, insertion-related pain, rare perforation or expulsion | None significant -- systemic exposure is low, so hepatic enzyme-inducing drugs do not reduce effectiveness the way they can with oral hormonal methods | Approved by Health Canada for idiopathic menorrhagia treatment for up to 5 years, and for contraception alone for up to 8 years -- these are two different approved durations for the same device. |
Combined hormonal contraceptives
A monophasic product is used as a representative example -- any monophasic combined hormonal method (pill, patch, or ring) is a reasonable choice; confirm the full contraindication profile (VTE history, migraine with aura, uncontrolled hypertension, smoking over age 35, etc.) before initiating any combined hormonal method.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Ethinyl estradiol / norethindrone (representative monophasic pill) | Chronic HMB, cyclic or continuous: One tablet PO daily, cyclic (21 active days + 7-day break) or continuous/extended regimen Acute severe bleeding taper: Monophasic pill (30-50 mcg ethinyl estradiol) every 6-8 hours until bleeding slows, then taper to standard cyclic dosing over the following days | Breakthrough bleeding (early cycles), nausea, breast tenderness | Reduced efficacy with strong hepatic enzyme inducers |
Gonadotropin-releasing hormone (GnRH) agonists
Usually given for 6 months or less, since long-term use causes a significant, only partly reversible decrease in bone mineral density. If continued beyond 6 months, add estrogen-progestogen add-back therapy to preserve bone health.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Goserelin acetate | Adults: 3.6 mg subcutaneous depot injection monthly | Vasomotor symptoms (hot flashes, vaginal dryness), insomnia, decreased libido, mood changes; bone loss if used beyond 6 months | None significant | |
| Leuprolide acetate | Adults: 3.75 mg intramuscular depot monthly | Vasomotor symptoms, insomnia, decreased libido, mood changes; bone loss if used beyond 6 months | None significant | |
| Nafarelin acetate | Adults: 200 mcg (1 spray) into one nostril each morning and the alternating nostril each evening, total 400 mcg/day | Vasomotor symptoms, insomnia, decreased libido, mood changes; bone loss if used beyond 6 months | None significant |
Gonadotropin-releasing hormone (GnRH) antagonist
Elagolix is approved by Health Canada only for moderate-to-severe endometriosis-associated pain -- using it specifically for fibroid-related HMB is off-label in Canada and should be reserved for specialist-directed use, with estrogen-progestogen add-back therapy to reduce hypoestrogenic effects.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Elagolix | Adults (approved endometriosis-pain dosing): 150 mg PO once daily, or 200 mg PO twice daily depending on regimen and duration -- per current product labelling | Hot flashes, night sweats, headache, mood changes; bone loss with prolonged use | None significant | Long-term safety data beyond the studied treatment duration are limited. |
Gonadotropin inhibitor (pituitary)
Poor tolerability from androgenic effects limits routine use to patients who have failed or cannot use other options.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Danazol | Adults: 100-400 mg PO daily | Androgenic effects (irreversible voice deepening, hirsutism, decreased breast size), weight gain, adverse LDL/HDL changes, vasomotor symptoms | None significant | Avoid in patients with dyslipidemia or liver disease. |
Acute severe bleeding -- additional hospital-based option
Intravenous conjugated estrogen was historically used to promote rapid endometrial proliferation over exposed spiral arteries in acute severe HMB, always followed by a progestogen or combined hormonal contraceptive to stabilize the endometrium once bleeding is controlled. It is not consistently stocked in Canadian hospital pharmacies today, so tranexamic acid and high-dose oral hormonal tapers (see above) are the more practical first choices in most Canadian settings.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Conjugated estrogens, intravenous | Adults: 25 mg IV or IM once, may repeat every 6 hours as needed until bleeding is controlled | Nausea, headache, breast tenderness, injection-site reaction; increased VTE/PE risk | Additive thrombotic risk with other prothrombotic therapy | Not the same product/formulation as oral conjugated estrogens (menopause indication) -- confirm local availability before including in a treatment plan. |
References
- No. 292-Abnormal Uterine Bleeding in Pre-Menopausal Women — Journal of Obstetrics and Gynaecology Canada, Society of Obstetricians and Gynaecologists of Canada (Singh S, Best C, Dunn S, Leyland N, Wolfman WL). J Obstet Gynaecol Can 2018;40(5):e391-e415
- The two FIGO systems for normal and abnormal uterine bleeding symptoms and classification of causes of abnormal uterine bleeding in the reproductive years: 2018 revisions — International Journal of Gynecology & Obstetrics, FIGO Menstrual Disorders Committee (Munro MG, Critchley HOD, Fraser IS). Int J Gynaecol Obstet 2018;143(3):393-408
- Heavy menstrual bleeding: assessment and management — National Institute for Health and Care Excellence, NICE guideline [NG88]. NICE NG88, published 14 Mar 2018, last updated 24 May 2021 (amended Dec 2024)
- CYKLOKAPRON (tranexamic acid) Product Monograph — Pfizer Canada ULC, Health Canada Drug Product Database. Health Canada Product Monograph
- Allergan Inc. voluntarily withdraws its drug Fibristal (ulipristal acetate), used to treat uterine fibroids, from the Canadian market — Recalls and safety alerts, Health Canada. Health Canada Recalls and Safety Alerts, September 24, 2020
- Antifibrinolytics for heavy menstrual bleeding — Cochrane Database of Systematic Reviews (Bryant-Smith AC, Lethaby A, Farquhar C, Hickey M). Cochrane Database Syst Rev 2018;4:CD000249
- Non-steroidal anti-inflammatory drugs for heavy menstrual bleeding — Cochrane Database of Systematic Reviews (Bofill Rodriguez M, Lethaby A, Farquhar C). Cochrane Database Syst Rev 2019;9:CD000400
- Progestogen-releasing intrauterine systems for heavy menstrual bleeding — Cochrane Database of Systematic Reviews (Bofill Rodriguez M, Lethaby A, Jordan V). Cochrane Database Syst Rev 2020;6:CD002126
- Levonorgestrel intrauterine system versus medical therapy for menorrhagia (ECLIPSE trial) — New England Journal of Medicine (Gupta J, Kai J, Middleton L, et al.; ECLIPSE Trial Collaborative Group). N Engl J Med 2013;368(2):128-137
- MIRENA (levonorgestrel-releasing intrauterine system) Product Monograph — Bayer Inc., Health Canada Drug Product Database. Health Canada Product Monograph
Professional reference only. Apply clinical judgment and verify patient-specific decisions against current authoritative guidance and product information.