Restless Legs Syndrome
Restless Legs Syndrome
References
- Restless legs syndrome/Willis-Ekbom disease diagnostic criteria: updated International Restless Legs Syndrome Study Group (IRLSSG) consensus criteria — history, rationale, description, and significance — Sleep Medicine (Allen RP, Picchietti DL, Garcia-Borreguero D, et al.). Sleep Med 2014;15(8):860-873
- Treatment of restless legs syndrome and periodic limb movement disorder: an American Academy of Sleep Medicine clinical practice guideline — Journal of Clinical Sleep Medicine (Winkelman JW, Berkowski JA, DelRosso LM, et al.). J Clin Sleep Med 2025;21(1):137-152
- Guidelines for the first-line treatment of restless legs syndrome/Willis-Ekbom disease, prevention and treatment of dopaminergic augmentation: a combined task force of the IRLSSG, EURLSSG, and the RLS-foundation — Sleep Medicine (Garcia-Borreguero D, Silber MH, Winkelman JW, et al.). Sleep Med 2016;21:1-11
- Willis-Ekbom Disease Foundation revised consensus statement on the management of restless legs syndrome — Mayo Clinic Proceedings (Silber MH, Becker PM, Earley C, et al.). Mayo Clin Proc 2013;88(9):977-986
- Evidence-based and consensus clinical practice guidelines for the iron treatment of restless legs syndrome/Willis-Ekbom disease in adults and children: an IRLSSG task force report — Sleep Medicine (Allen RP, Picchietti DL, Auerbach M, et al.). Sleep Med 2018;41:27-44
- Consensus clinical practice guidelines for the diagnosis and treatment of restless legs syndrome/Willis-Ekbom disease during pregnancy and lactation — Sleep Medicine Reviews (Picchietti DL, Hensley JG, Bainbridge JL, et al.). Sleep Med Rev 2015;22:64-77
- Management of restless leg syndrome in pregnancy and lactation — Journal of Primary Care & Community Health (Kondori MJ, Kolla BP, Moore KM, Mansukhani MP). J Prim Care Community Health 2020;11:2150132720905950
Clinical Snapshot
Restless legs syndrome (RLS), also known as Willis-Ekbom disease, is a neurologic sensorimotor disorder defined by an urge to move the legs, usually accompanied by an uncomfortable sensation, that begins or worsens with rest, is partially or fully relieved by movement, and is worse in the evening or at night.[1] Primary (idiopathic) RLS has a genetic component and is linked to reduced brain iron availability and dysfunctional dopaminergic signalling, even when peripheral iron studies look reassuring at first glance; secondary RLS arises from an identifiable cause such as iron deficiency, end-stage renal disease, or pregnancy, and often improves once that cause is treated. The single most important, and most often skipped, first step in management is checking iron studies — a ferritin below the RLS-specific threshold warrants iron repletion even in a patient whose hemoglobin is entirely normal. Long-term pharmacologic management has shifted substantially in recent years: alpha-2-delta ligands (gabapentin, pregabalin) are now preferred first-line therapy, and dopamine agonists — once the standard first choice — are reserved for selected situations because of a well-documented risk of augmentation, a paradoxical worsening of RLS caused by the treatment itself.[2]
Recognize the Condition
Core clinical features
Patients describe an urge to move the legs, often together with an uncomfortable, hard-to-articulate sensation variably described as crawling, aching, pulling, itching, or an electric-current feeling deep in the limb. Symptoms are typically bilateral, though can be unilateral or asymmetric, and in more severe or long-standing disease can extend to the arms and trunk. Because the discomfort emerges specifically with rest and inactivity — sitting still, lying down, air travel, long meetings — and eases with movement, patients often develop a strong urge to get up and walk, which can be mistaken for anxiety, akathisia, or simple insomnia if the clinician does not ask about the rest-dependent, evening-predominant pattern directly.
The 5 required diagnostic criteria
RLS is a clinical diagnosis; there is no confirmatory laboratory or imaging test. All 5 of the following must be present:[1]
- An urge to move the legs, usually accompanied or caused by an uncomfortable sensation in the legs.
- Symptoms begin or worsen specifically during periods of rest or inactivity, such as lying or sitting.
- Symptoms are partially or totally relieved by movement (walking, stretching), for at least as long as the activity continues.
- Symptoms are worse in the evening or night, or occur only in the evening or night.
- The symptoms are not solely accounted for by another condition (e.g., myalgia, arthritis, leg cramps, positional discomfort, habitual foot tapping).
Supportive (not required) features include a positive family history, a clear symptomatic response to dopaminergic therapy, and periodic limb movements seen during wakefulness or on polysomnography.[1]
Primary vs. secondary RLS
Primary (idiopathic) RLS
No identifiable secondary cause. Believed to involve a genetic component together with reduced brain iron availability and dysfunctional dopaminergic transmission. Usually chronic and often slowly progressive.
Secondary RLS
Arises in the context of an identifiable contributing condition — most importantly iron deficiency (with or without anemia), end-stage renal disease, pregnancy, peripheral neuropathy, or a causative/aggravating medication. Treating or removing the underlying cause often substantially improves or resolves symptoms.
Risk Factors
- Family history of RLS — roughly half of people with RLS have a first-degree relative with the disorder, reflecting a genetic component.
- Iron deficiency, with or without anemia — the single most correctable and most commonly missed risk factor.
- End-stage renal disease, including patients on hemodialysis or peritoneal dialysis.
- Pregnancy, particularly the third trimester.
- Parkinson disease and other conditions affecting dopaminergic pathways.
- Multiple sclerosis.
- Peripheral neuropathy of any cause, including diabetes mellitus.
- Venous insufficiency (visible varicose veins).
- Untreated obstructive sleep apnea, which can aggravate both RLS and periodic limb movements.[2]
- A medication known to cause or aggravate RLS — antidepressants, first-generation antihistamines, antidopaminergic antiemetics, and antipsychotics are the most frequently implicated classes (see Non-pharmacologic Treatment for the full medication-review list).[2]
Red Flags & Refer
Refer or escalate for any of the following:
- Signs of augmentation in a patient on a dopamine agonist — earlier symptom onset than before treatment, a shorter latency to symptoms at rest, spread of symptoms to the arms/trunk, or a shortened duration of drug effect. This needs prompt reassessment and a management change, not simply a higher dose.[3]
- Severe iron deficiency anemia — needs hematology work-up for the underlying cause of the iron deficiency itself, not just RLS-focused iron repletion.
- Symptoms suggesting an alternative diagnosis rather than RLS — peripheral neuropathy (distal sensory loss, constant rather than rest-dependent symptoms), akathisia (inner restlessness associated with an antipsychotic or antiemetic, without the specific rest-triggered, movement-relieved, evening-predominant pattern), or nocturnal leg cramps (a painful, palpable muscle contraction, not simply relieved by any movement).
- New or worsening impulse control behaviours (pathological gambling, hypersexuality, compulsive shopping or eating) emerging in a patient on a dopamine agonist.
- Suicidal ideation or behaviour emerging on an alpha-2-delta ligand.
- Suspected untreated obstructive sleep apnea in a patient being considered for opioid therapy — screen and treat before starting.
Assessment & Diagnosis
Differentiating RLS from its common mimics
| Feature | RLS | Peripheral neuropathy | Nocturnal leg cramps | Akathisia |
|---|---|---|---|---|
| Core sensation | Urge to move, with an uncomfortable (not usually painful) deep limb sensation | Numbness, tingling, or burning pain, usually constant | Sudden, painful, palpable muscle tightening/spasm | Inner restlessness/unease, a general inability to sit still, not localized to the legs |
| Effect of movement | Partially or fully relieved by movement, for as long as movement continues | Not specifically relieved by movement | Relieved by stretching the specific affected muscle | Movement/pacing gives only brief or partial relief |
| Timing | Worse in the evening/night, or only then | Constant, not specifically evening-predominant | Can occur at any time, often at night | Related to the timing of the causative medication, not a fixed circadian pattern |
| Trigger for rest/inactivity | Symptoms begin or worsen specifically with rest | Not specifically rest-triggered | Not specifically rest-triggered | Not specifically rest-triggered |
| Associated clues | Family history, response to dopaminergic/alpha-2-delta therapy, low ferritin | Distal sensory loss, absent reflexes, diabetes/alcohol use/B12 deficiency history | Visible/palpable muscle contraction during the episode | Recent start or dose increase of an antipsychotic or antiemetic |
Classifying RLS by frequency, since this shapes treatment intensity
Intermittent RLS: symptoms occurring on average less than twice a week, but bothersome enough to need occasional treatment. Chronic persistent RLS: symptoms occurring on average at least twice a week, causing moderate-to-severe distress, frequent and bothersome enough to require daily therapy. Refractory RLS: inadequate response to, or intolerable side effects from, an adequately dosed first-line agent, including after augmentation has been addressed.[4]
History
- Screen directly using the 5 diagnostic criteria rather than relying on a vague complaint of "restless legs", since patients rarely volunteer the specific rest-triggered, evening-predominant, movement-relieved pattern unprompted.
- Ask about sleep quality and daytime function, and — where relevant — ask a bed partner about leg movements during sleep.
- Review the full medication list specifically for RLS-aggravating agents.
- Ask about symptoms suggesting a secondary cause: diabetes/neuropathy symptoms, kidney disease, pregnancy, and family history.
Investigations
- Ferritin and transferrin saturation (TSAT) — see Choose Initial Treatment for the specific thresholds that drive oral vs. IV iron therapy.
- CBC, electrolytes, urea, creatinine, and fasting glucose — screens for anemia, renal impairment, and diabetes-related neuropathy as contributing/secondary causes.
- Nerve conduction studies if the history or exam suggests peripheral neuropathy rather than (or in addition to) RLS.
- Polysomnography if there is clinical suspicion of obstructive sleep apnea or another concurrent sleep disorder — not needed to diagnose RLS itself, which remains a clinical diagnosis.
International Restless Legs Syndrome Severity Scale (IRLS)
The IRLS is a 10-item, patient-rated severity scale (each item scored 0-4, total 0-40) used to grade symptom severity and track response to treatment over time — it is a monitoring and outcome-tracking tool, not a diagnostic test; the 5 clinical criteria above are what establish the diagnosis.[2]
| Score range | Severity |
|---|---|
| 1-10 | Mild |
| 11-20 | Moderate |
| 21-30 | Severe |
| 31-40 | Very severe |
Unlike a short bedside point-sum such as TIMI (a handful of present/absent clinical criteria), the IRLS asks the patient to rate 10 separate dimensions — symptom severity, frequency, sleep disturbance, daytime tiredness, and effect on mood/daily activities — on a 5-point descriptive scale. Reproducing it as a simplified interactive checkbox tool risks trivializing a validated, copyrighted clinical-trial outcome instrument, so it is presented here as a teaching table only; use the validated instrument directly, or a treating sleep specialist, for formal severity scoring.
When testing is not needed
Nerve conduction studies and polysomnography are not routine for every RLS patient — reserve them for cases where the history specifically raises peripheral neuropathy or a coexisting sleep disorder, rather than ordering them by default.
Treatment Targets
- Reduce the frequency, intensity, and duration of the urge-to-move and unpleasant limb sensations.
- Improve sleep onset and sleep continuity.
- Improve daytime function in patients with daytime symptoms or sleep-deprivation effects.
- Correct iron deficiency to a ferritin level above the RLS-specific repletion threshold, not merely into the general-population "normal" range.
- Reduce disruptive periodic limb movements during sleep, when present and bothersome.
- Avoid or minimize the risk of augmentation and rebound from the treatment itself.
Choose Initial Treatment
Step 1 — always address reversible contributors first
Every patient gets iron studies and a medication review before or alongside starting RLS-specific pharmacotherapy — correcting these can resolve or substantially improve symptoms on its own.[2]
Step 2 — iron repletion, driven by ferritin/transferrin saturation
Ferritin ≤75 ng/mL, or transferrin saturation <20% start oral iron (ferrous sulfate) or IV iron.[5]
Ferritin 75-100 ng/mL use IV iron (ferric carboxymaltose) only — oral iron is poorly absorbed once ferritin is in this range, so escalating the oral dose is not the correct next step.[2]
Ferritin >100 ng/mL iron repletion is not indicated on ferritin grounds alone; proceed directly to RLS-specific pharmacotherapy if symptoms remain clinically significant.
Step 3 — pharmacotherapy for symptoms that remain clinically significant
1st line an alpha-2-delta ligand — gabapentin or pregabalin — for essentially all adults who need daily or near-daily pharmacotherapy.[2]
Use a dopamine agonist (pramipexole, ropinirole, or transdermal rotigotine) only in selected situations — short-term/occasional use (e.g., air travel), or when alpha-2-delta ligands are not tolerated or not effective — and only after explicitly counselling the patient on augmentation risk; this is a genuine reversal from older teaching that positioned dopamine agonists as standard first-line therapy.[2]
Occasional/as-needed symptoms (intermittent RLS) an as-needed alpha-2-delta ligand is still preferred; a short-acting low-potency opioid (e.g., codeine) used only as needed is a reasonable alternative for occasional symptoms.[4]
Do not start cabergoline or clonazepam, and do not start bupropion, carbamazepine, or valproic acid, as RLS treatment — current evidence does not support these, and cabergoline in particular carries a cardiac valvulopathy risk.[2]
Non-Pharmacologic Treatment
- Engage in mentally alerting activities (cards, video games, crossword puzzles) during periods of enforced rest to reduce symptom perception.
- Avoid alcohol, caffeine, and nicotine, all of which can aggravate RLS.
- Hot baths, stretching, and moderate exercise can help; yoga and massage may also provide benefit.
- Address untreated obstructive sleep apnea, which can aggravate both RLS and periodic limb movements.[2]
- In patients with RLS and visible varicose veins, treatment of the venous insufficiency (e.g., sclerotherapy) can improve RLS symptoms.
- A trial of pneumatic compression devices, worn on the legs for at least an hour before the usual onset of symptoms, is a reasonable option for patients who do not respond to or cannot tolerate pharmacotherapy.
- Bilateral high-frequency peroneal nerve stimulation is a further non-pharmacologic option with evidence of benefit for patients who have not responded adequately to standard therapy.[2]
Medications that can cause or aggravate RLS — review and discontinue where possible
This is explicitly identified as the first step in management, before or alongside starting RLS-specific pharmacotherapy.[2]
Antidepressants
Most SSRIs and SNRIs, and especially mirtazapine, can precipitate or worsen RLS. If an antidepressant is contributing, discuss a dose reduction or a switch with the prescriber rather than simply adding an RLS medication on top; bupropion is sometimes used as an alternative antidepressant specifically because it lacks this serotonergic mechanism, though it is not itself an effective RLS treatment.
Antihistamines
First-generation, sedating antihistamines such as diphenhydramine commonly worsen RLS — avoid recommending these as an over-the-counter sleep aid in a patient with RLS.
Antidopaminergic antiemetics
Metoclopramide and prochlorperazine can precipitate or worsen RLS through dopamine-receptor blockade.
Antipsychotics
Dopamine-blocking antipsychotics — particularly quetiapine, olanzapine, and clozapine — are commonly reported to cause or worsen RLS; this is rarely a reason to stop an antipsychotic outright, but it should factor into agent selection and be discussed with the prescriber.
Pharmacologic Treatment Options
| Drug / intervention | Role | Dose / use | Important adverse effects | Teaching points |
|---|---|---|---|---|
| Ferrous sulfate Preferred | Oral iron repletion, ferritin ≤75 ng/mL or TSAT under 20% | 300-325 mg (60-65 mg elemental iron) PO once daily, with vitamin C to enhance absorption | Constipation, nausea, dark stools | First step for essentially every RLS patient with a low ferritin — check levels before assuming dopaminergic/alpha-2-delta therapy is needed. |
| Ferric carboxymaltose Preferred | IV iron, ferritin ≤100 ng/mL, or oral iron not tolerated/effective | Weight-based IV infusion per product dosing (see Drug Tables) | Hypophosphatemia, injection-site reactions, rare hypersensitivity | Oral iron is poorly absorbed once ferritin exceeds roughly 50-75 ng/mL — IV iron is the correct next step, not a higher oral dose. |
| Gabapentin Preferred | 1st-line pharmacotherapy, chronic persistent RLS | 300-1200 mg PO once daily, 1-2 hours before bedtime; up to 3600 mg/day in refractory cases | Somnolence, dizziness, peripheral edema | Preferred over a dopamine agonist as initial therapy — minimal augmentation risk. |
| Pregabalin Preferred | 1st-line pharmacotherapy, chronic persistent RLS | 50-150 mg PO once daily, 1-3 hours before bedtime; up to 300 mg/day | Somnolence, dizziness, weight gain | Consider switching to pregabalin from a dopamine agonist if augmentation develops. |
| Pramipexole Special situation | Short-term/occasional use only, after augmentation risk discussed | Initial 0.125 mg PO once daily, ≥2h before symptom onset; usual 0.25-0.75 mg/day | Nausea, somnolence, impulse control disorders, augmentation | No longer standard first-line therapy — reserve for short-term use (e.g., travel) or when alpha-2-delta ligands fail/aren't tolerated. |
| Ropinirole Special situation | Short-term/occasional use only, after augmentation risk discussed | Initial 0.25 mg PO once daily, ≥2h before symptom onset; usual 1-4 mg/day | Nausea, somnolence, impulse control disorders, augmentation | Same augmentation-risk caveat as pramipexole — not standard first-line therapy. |
| Rotigotine Special situation | Short-term/occasional use only, after augmentation risk discussed | 1-3 mg/24h transdermal patch once daily | Application-site reactions, nausea, somnolence, augmentation | Same augmentation-risk caveat as other dopamine agonists — not standard first-line therapy. |
| Levodopa / carbidopa Special situation | As-needed use, intermittent RLS only | 50/12.5 mg PO PRN before anticipated symptom onset; up to 200/50 mg | Nausea, augmentation and rebound (highest risk of any RLS agent) | Restrict to occasional/as-needed use — daily use carries the highest augmentation/rebound risk of any available agent. |
| Codeine Alternative | Intermittent RLS, or refractory RLS adjunct | 30-60 mg PO PRN, up to 180 mg/day | Sedation, constipation, dependence | Low-potency opioid option for occasional symptoms; screen for obstructive sleep apnea before starting any opioid. |
| Oxycodone (extended-release) Special situation | Refractory RLS, after iron status and alpha-2-delta ligand optimized | Individualized extended-release dosing, titrated to the lowest effective dose | Sedation, constipation, dependence, respiratory depression | Reserve for genuinely refractory disease; screen for sleep apnea and assess misuse risk before starting. |
| Cabergoline Avoid | Not recommended | Not applicable | Cardiac valvulopathy, augmentation, dizziness/vertigo | Avoid — ergot-derived dopamine agonist with a strong recommendation against use given valvulopathy and augmentation risk. |
Special Populations
Pregnancy
Check iron studies and correct iron deficiency — this is both a common contributor to gestational RLS and a standard part of routine prenatal care; confirm the total elemental iron dose across all products, including a prenatal vitamin, before adding supplemental iron.
If pharmacotherapy is genuinely needed despite non-pharmacologic measures and iron correction, defer starting it until the second trimester where possible to reduce the risk of adverse pregnancy outcomes associated with earlier exposure.[7]
Levodopa/carbidopa may be considered if pharmacotherapy is required, reflecting the most available (though still limited) reassuring safety data among RLS drugs in pregnancy; re-evaluate the need for ongoing therapy regularly, since symptoms typically resolve after delivery.[6]
Opioids can be used for severe, refractory symptoms in pregnancy but should be avoided close to term because of the risk of neonatal respiratory depression.
Breastfeeding
Non-pharmacologic measures remain first-line while breastfeeding. Limited data suggest gabapentin produces relatively low infant serum levels and may be a reasonable choice if pharmacotherapy is needed. Dopamine agonists (pramipexole, ropinirole, rotigotine) suppress prolactin and may interfere with lactation; data on their use during breastfeeding are lacking.[6]
Pediatrics
Ferrous sulfate is the only pharmacologic RLS treatment currently supported by evidence specifically in children, used when iron status meets the pediatric repletion threshold (ferritin <50 ng/mL).[2] Evidence is insufficient to support treating children with the other agents used in adult RLS — work with a pediatric sleep specialist for a child whose RLS remains clinically significant despite iron correction and non-pharmacologic measures.
End-stage renal disease
Gabapentin is a reasonable option, with renal dose adjustment, in patients with RLS and end-stage renal disease.[2] IV iron sucrose is an option specifically when ferritin is under 200 ng/mL and transferrin saturation is under 20% in this population — a different, higher ferritin threshold than for RLS patients without renal disease, reflecting the altered iron kinetics of end-stage renal disease.[2] Levodopa and rotigotine are not recommended for standard use in RLS with end-stage renal disease, for the same augmentation-risk reasons as in the general RLS population.
Older adults
Screen carefully for polypharmacy and RLS-aggravating medications, which accumulate with age. Benzodiazepines are not preferred RLS therapy at any age per current evidence, and carry added fall and cognitive-impairment risk specifically in older adults. Monitor closely for impulse control disorders and orthostatic hypotension if a dopamine agonist is used in this population.
Renal and hepatic impairment (non-dialysis)
Gabapentin and pregabalin are renally cleared and require dose reduction as creatinine clearance falls — consult the Drug Database entry for the specific adjustment. No specific hepatic dose adjustment is required for the alpha-2-delta ligands.
Monitoring & Follow-Up
Recheck ferritin and transferrin saturation roughly 6-8 weeks after starting iron repletion to confirm response and to guide whether to continue, adjust the dose, or move from oral to IV iron. At every follow-up visit for a patient on a dopamine agonist, ask specifically about earlier symptom onset, spread of symptoms to new body areas, and any new compulsive or impulsive behaviour (gambling, hypersexuality, compulsive shopping or eating) — both augmentation and impulse control disorders can develop gradually and are easy to miss unless asked about directly.[3] For a patient on an alpha-2-delta ligand, ask about excessive daytime sedation, unsteady gait (particularly in older adults), and any new or worsening mood changes or suicidal ideation. Track symptom severity over time with the IRLS scale, or simply by asking about frequency, bothersomeness, and sleep impact at each visit. Reassess the ongoing need for pharmacotherapy periodically, since RLS severity can fluctuate and some patients — especially those whose RLS was iron-deficiency-driven or pregnancy-related — may be able to taper off treatment entirely.
Treatment Failure / Next Step
- Recheck iron studies if this has not been done recently, and confirm adherence to both the RLS medication and any prescribed iron therapy.
- Reconfirm the medication list for a newly started or dose-increased RLS-aggravating drug (antidepressant, antihistamine, antiemetic, antipsychotic), and screen for untreated obstructive sleep apnea.
- If the patient is on an alpha-2-delta ligand: optimize the dose and, if needed, split the dose (afternoon plus evening) for patients with earlier daytime symptom onset, before concluding the drug has failed.
- If the patient is on a dopamine agonist and symptoms are worsening: distinguish augmentation (earlier onset, shorter latency to symptoms at rest, spread to new body areas, shortened drug effect) from simple disease progression or tolerance — do not increase the dopamine agonist dose in response to true augmentation, since this predictably worsens it.[3]
- For confirmed augmentation: add or switch to an alpha-2-delta ligand and begin a gradual taper of the dopamine agonist, monitoring closely for rebound RLS and mood symptoms during the taper; a short-term low-dose opioid can help bridge symptoms during the taper.[3]
- For genuinely refractory RLS (inadequate response to, or intolerable side effects from, an adequately dosed first-line agent): consider combining agents from different classes — for example, an alpha-2-delta ligand plus a low-dose opioid — rather than escalating a single agent beyond its usual effective range.[4]
- Refer to a sleep medicine specialist for refractory RLS, an uncertain diagnosis, suspected augmentation requiring a complex taper, or a coexisting sleep disorder that needs formal evaluation.
Common Errors to Avoid
- Starting a dopamine agonist as routine first-line therapy without discussing augmentation risk — current evidence no longer supports this as the default choice.
- Treating iron deficiency based on hemoglobin or a routine CBC alone — ferritin and transferrin saturation must be checked specifically, since RLS-relevant iron deficiency can exist with a completely normal hemoglobin.
- Increasing a dopamine agonist's dose in response to worsening symptoms without first considering augmentation — this is the single most common mistake in long-term dopamine agonist management, and predictably makes true augmentation worse.
- Stopping a dopamine agonist abruptly in a patient with confirmed augmentation — this risks severe rebound symptoms; taper gradually while adding an alternative agent.
- Missing a medication-review opportunity — overlooking an antidepressant, antihistamine, antiemetic, or antipsychotic that is causing or worsening the patient's RLS.
- Prescribing gabapentin or pregabalin without adjusting for renal function.
- Assuming benzodiazepines are a good first choice for RLS-related sleep disturbance — current evidence does not support this despite older teaching.
- Not screening for impulse control disorders in a patient on a dopamine agonist — these can occur even at low doses and are easy to miss unless asked about directly.
- Reflexively treating RLS symptoms in pregnancy with a dopamine agonist or another agent lacking pregnancy safety data, instead of starting with iron correction and non-pharmacologic measures.
Clinical Decision Algorithm
Drug Tables
How to use this table: Doses are adult doses and require patient-specific confirmation, including renal/hepatic adjustment. Select any drug name to open its complete Pharmasist Drug Database page.
Iron therapy
Iron studies (ferritin, transferrin saturation) should be checked before choosing a formulation — see Choose Initial Treatment for the specific thresholds. Further IV options exist beyond ferric carboxymaltose — low molecular weight iron dextran and ferumoxytol both carry a conditional recommendation for RLS, chosen based on local availability and infusion-time preference — but ferric carboxymaltose has the strongest supporting evidence and the only strong recommendation among IV iron formulations.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Ferrous sulfate | Adults: 300-325 mg (60-65 mg elemental iron) PO once daily; may be increased to BID/TID if tolerated Children: Weight-based (mg elemental iron/kg/day), individualized to the specific product — see Drug Database entry | Constipation, nausea, abdominal cramping, dark/black stools, metallic taste | Reduces absorption of levothyroxine, bisphosphonates, tetracyclines, fluoroquinolones — separate by ≥2h; antacids/calcium/PPIs reduce iron absorption | First-line oral option when ferritin ≤75 ng/mL or TSAT under 20%. Take with vitamin C to enhance absorption; alternate-day dosing can improve tolerability and fractional absorption. |
| Ferric carboxymaltose | Adults: Weight- and hemoglobin-based total dose, given as 1-2 IV infusions — see Drug Database entry for the full dosing table Children: Not established for routine pediatric use — specialist-directed only | Hypophosphatemia (can be clinically significant), injection-site reactions, transient nausea/flushing, rare hypersensitivity | Avoid concurrent oral iron; no other significant interactions | Strong-recommendation option given multiple supporting randomized trials. Use when ferritin is ≤100 ng/mL, or when oral iron is not tolerated or not effective. Access/reimbursement specifically for RLS can be limited outside specialized centres. |
Alpha-2-delta ligands
Gabapentin enacarbil, a gabapentin prodrug with more consistent absorption dosed once daily, is ranked alongside gabapentin and pregabalin as strongly recommended first-line therapy, but it is not currently marketed in Canada — gabapentin and pregabalin are the practical first-line choices.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Gabapentin | Adults: Initial 300 mg PO once daily, 1-2 hours before bedtime; titrate gradually to effect; usual 900-1800 mg/day; up to 3600 mg/day used in refractory disease Renal impairment / ESRD: Reduced dose required — see Drug Database entry | Somnolence, dizziness, ataxia, peripheral edema, weight gain; monitor for suicidal ideation | Additive CNS depression with other sedating drugs; increased respiratory depression risk combined with opioids | Preferred first-line agent alongside pregabalin — minimal augmentation risk. |
| Pregabalin | Adults: Initial 50 mg PO once daily, 1-3 hours before bedtime; titrate every few days to effect; usual 150-300 mg/day Renal impairment: Reduced dose required — see Drug Database entry | Somnolence, dizziness, ataxia, peripheral edema, weight gain; monitor for suicidal ideation | Additive CNS depression with other sedating drugs; increased respiratory depression risk combined with opioids | Consider switching to pregabalin specifically when augmentation develops on a dopamine agonist. |
Dopamine agonists
No longer standard first-line therapy. Current evidence supports a conditional recommendation against routine/standard use of every agent in this class, given a well-documented risk of augmentation — a paradoxical worsening of RLS caused by the treatment itself. Reserve for short-term/occasional use, or when alpha-2-delta ligands are not tolerated or effective, after explicitly counselling the patient on augmentation risk. Taper gradually when discontinuing any of these agents; do not stop abruptly.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Pramipexole | Adults: Initial 0.125 mg PO once daily, ≥2 hours before usual symptom onset; increase every 4-5 days until effective; usual 0.25-0.75 mg/day | Nausea, somnolence, orthostatic hypotension, sudden sleep attacks, impulse control disorders (pathological gambling, hypersexuality, compulsive shopping/eating), augmentation | First-generation antipsychotics blunt effect; additive hypotension with antihypertensives | Nonergoline derivative — more favourable side-effect profile than bromocriptine. Monitor for compulsive behaviours at every visit. |
| Ropinirole | Adults: Initial 0.25 mg PO once daily, ≥2 hours before usual symptom onset; increase every 4-5 days until effective; usual 1-4 mg/day | Nausea, somnolence, orthostatic hypotension, sudden sleep attacks, impulse control disorders, augmentation | Ciprofloxacin increases ropinirole levels; additive hypotension with antihypertensives | Nonergoline derivative. Monitor for compulsive behaviours at every visit. |
| Rotigotine | Adults: 1-3 mg/24h transdermal patch once daily | Application-site reactions, nausea, somnolence, orthostatic hypotension, sudden sleep attacks, impulse control disorders, augmentation | Additive hypotension with antihypertensives | Transdermal patch, useful when a steady 24-hour delivery is preferred. Rotate application sites; avoid the same site within 14 days; avoid external heat over the patch. |
| Cabergoline | Adults: Not applicable — avoid | Cardiac valvulopathy, dizziness/vertigo, augmentation | Additive hypotension with antihypertensives | Strong recommendation against use — associated with cardiac valvulopathy in addition to the augmentation and impulse-control risks shared with other dopamine agonists. Avoid. |
Levodopa preparations
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Levodopa / carbidopa | Adults, as-needed only: 50/12.5 mg PO PRN before anticipated symptom onset; up to 200/50 mg | Nausea, lightheadedness, dry mouth, augmentation and rebound (highest risk of any RLS agent) | First-generation antipsychotics decrease effect; antihypertensives/diuretics/tricyclic antidepressants may increase hypotensive effect; reduced absorption with high-protein meals | Restrict to occasional/as-needed use for intermittent RLS — daily use carries the highest augmentation/rebound risk of any available agent. |
Benzodiazepines
Current evidence does not support this class as routine RLS therapy — clonazepam specifically carries a conditional recommendation against use, and triazolam is separately recommended against specifically for periodic limb movement disorder. Temazepam was not evaluated in the current AASM guideline; older consensus statements suggested it for sleep quality in intermittent RLS, but this is not supported by current formal evidence review.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Clonazepam | Adults: Not recommended — avoid as RLS therapy | Sedation, dizziness, cognitive impairment, dependence, fall risk | Additive sedation with other CNS depressants, including alcohol | Current evidence does not support clonazepam as RLS treatment (conditional recommendation against). Avoid, particularly in older adults, given fall and cognitive-impairment risk. |
| Temazepam | Adults: Not established as RLS therapy — evidence insufficient | Sedation, dizziness, dependence | Additive sedation with other CNS depressants, including alcohol | Not evaluated in the current AASM guideline. Intermediate duration of action if used for a coexisting sleep complaint, not RLS itself. |
| Triazolam | Adults: Not recommended for periodic limb movement disorder — avoid | Sedation, dizziness, dependence, next-day sedation | Additive sedation with other CNS depressants, including alcohol | Specifically recommended against for periodic limb movement disorder; not separately evaluated for RLS. |
Opioids
Screen for obstructive sleep apnea before starting any opioid, and reassess regularly given dependence/misuse risk. Extended-release oxycodone has the strongest evidence among opioids specifically for RLS.
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Codeine | Immediate-release, PRN: 30-60 mg PO PRN; up to 180 mg/day, divided if needed Sustained-release: 50-150 mg/day PO, divided Q12H, for patients needing a longer-acting occasional option | Sedation, constipation, nausea, dependence | Additive CNS/respiratory depression with other sedating drugs, especially alpha-2-delta ligands and benzodiazepines | Low-potency opioid option for intermittent/occasional RLS. |
| Oxycodone | Immediate-release: 5-30 mg/day PO, divided if needed Extended-release: Individualized extended-release dosing, titrated to the lowest effective dose | Sedation, constipation, dependence, respiratory depression | Additive CNS/respiratory depression with other sedating drugs, especially alpha-2-delta ligands and benzodiazepines | Reserve for refractory RLS after iron status and alpha-2-delta ligand therapy have been optimized. Extended-release formulation has the strongest evidence among opioids for RLS. |
| Methadone | Adults: 5-40 mg/day PO, divided if needed | Sedation, constipation, dependence, QTc prolongation | CYP3A4 substrate — avoid strong inducers/inhibitors; additive QTc prolongation with other QT-prolonging drugs; additive CNS/respiratory depression with other sedating drugs | Reserved for refractory RLS. Obtain a baseline ECG and monitor QTc given prolongation risk. |
| Oxycodone / naloxone (controlled-release) | Adults: Individualized controlled-release dosing (oxycodone component), once daily at bedtime | Sedation, constipation (reduced relative to oxycodone alone), dependence | Additive CNS/respiratory depression with other sedating drugs | The naloxone component specifically offsets opioid-induced constipation. Reserve for refractory RLS. |
Other agents with limited evidence of benefit
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Dipyridamole | Adults: Per product dosing — see Drug Database entry | Headache, dizziness, GI upset, flushing | Additive hypotension with antihypertensives; additive bleeding risk with antiplatelet/anticoagulant drugs | A conditional-recommendation option based on limited trial evidence — not a standard first- or second-line choice, but a reasonable option when preferred agents fail or are not tolerated. |
Not recommended / insufficient evidence
| Drug | Dosage | Adverse effects | Drug interactions | Comments |
|---|---|---|---|---|
| Bupropion | Adults: Not recommended as RLS therapy | Nausea, irritable mood, insomnia | Lowers seizure threshold; avoid with other drugs that also lower seizure threshold | Not effective for RLS itself, despite lacking the serotonergic mechanism that worsens RLS with other antidepressants. Current evidence does not support its use as RLS treatment. |
| Carbamazepine | Adults: Not recommended as RLS therapy | Dizziness, hepatotoxicity, hematologic adverse effects | Potent CYP450 inducer — numerous interactions | No clinically significant RLS benefit demonstrated; hepatotoxicity and hematologic risk make this an unfavourable choice given better-evidenced alternatives. |
| Valproic acid | Adults: Not recommended as RLS therapy | Hepatotoxicity, teratogenicity, weight gain | Multiple CYP450/protein-binding interactions | No clinically significant RLS benefit demonstrated; hepatotoxicity and teratogenicity risk. |
| Clonidine | Adults: Not established as RLS therapy — evidence insufficient | Hypotension, sedation, dry mouth | Additive hypotension/sedation with other antihypertensives/CNS depressants | Insufficient evidence to make a recommendation for or against; not established as RLS therapy. |
| Tramadol | Adults: Not established as RLS therapy — evidence insufficient | Sedation, nausea, seizure risk at high dose | Serotonin syndrome risk with serotonergic drugs; additive CNS/respiratory depression with other sedating drugs | Insufficient evidence to recommend for or against; case reports describe both symptom benefit and paradoxical RLS augmentation/induction with tramadol specifically — avoid using it as a primary RLS treatment strategy. |
Amantadine, baclofen, and nortriptyline have been studied only in small, older trials and were not evaluated in the current AASM guideline — evidence is insufficient to recommend them, and better-evidenced options (iron repletion, alpha-2-delta ligands) should be exhausted first before considering any of these under specialist direction. Valerian, a natural health product sometimes used for RLS, is specifically recommended against by the AASM given a lack of demonstrated benefit.
Professional reference only. Apply clinical judgment and verify patient-specific decisions against current authoritative guidance and product information.