Class: Antimigraine Serotonin Receptor Agonist
Dosage Forms. Tablet: 25 mg, 50 mg, 100 mg
Common FDA Label Indication, Dosing, and Titration.
1. Migraine: 25-100 mg po at onset of migraine, may repeat after 2 h prn; max 200 mg/d
1. Corneal lesion pain: 25-100 mg po once
MOA. Sumatriptan binds with high affinity to serotonin (5HT) subtypes 1B, 1D and 1F receptors. It has no significant affinity or pharmacological activity at adrenergic α1, α,2, or β; dopaminergic D1 or D2; muscarinic; or opioid receptors. Serotonin receptor agonists are believed to be effective in migraine either through vasoconstriction (via activation of 5-HT1 receptors located on intracranial blood vessels) or through activation of 5-HT1 receptors on sensory nerve endings in the trigeminal system resulting in the inhibition of pro-inflammatory neuropeptide release.
Drug Characteristics: Sumatriptan
Medication Safety Issues: Sumatriptan
Drug Interactions: Sumatriptan
Adverse Reactions: Sumatriptan
Efficacy Monitoring Parameters. Resolution of clinical signs of migraine headache.
Toxicity Monitoring Parameters. Signs of ischemic bowel disease (eg, sudden severe abdominal pain, bloody diarrhea) or peripheral vascular disease, serotonin syndrome (eg, agitation, hallucinations, tachycardia, hyperthermia, labile blood pressure, hyperreflexia, incoordination, diarrhea, nausea, and vomiting), ischemic cardiac syndrome, or hypertensive crisis.
Key Patient Counseling Points. Avoid activities requiring mental alertness or coordination until drug effects are realized, as this drug may cause dizziness or somnolence.
Clinical Pearls. Sumatriptan is also available in formulations for nasal and injectable administration, and as an oral dosage form in combination with naproxen. These agents are not for prophylaxis; only for the treatment of acute migraine headache. Several serotonin agonists (“triptans”) exist for migraine, administered via a variety of routes (oral, inhaled, and injected). Each differs in onset and duration of action. If one agent is ineffective at max dose, recommend changing agents or route. Instruct patients to take a second dose 2 or more hours after the first, if needed, but no more than 200 mg/d.