Migraine and headache:

Indications for: IMITREX TABLETS

Acute treatment of migraine.

Limitations of Use:

Confirm diagnosis of migraine or cluster headache. Do not use for the prevention of migraine or cluster headache attacks.

Clinical Trials:

  • Imitrex Tablets was evaluated for the acute treatment of migraine headaches in 3 randomized, double-blind, placebo-controlled trials. Patients were instructed to treat a moderate to severe headache. Patients were allowed to take a second dose of Imitrex tablets or other medication 4 to 24 hours after the initial treatment for recurrent headache.

  • Headache response was defined as a reduction in headache severity from moderate to severe pain to mild or no pain and was assessed up to 2 hours after dosing. Maintenance of response was assessed for up to 24 hours post-dose.

  • In all 5 trials, a greater percentage of patients treated with Imitrex 25mg, 50mg, and 100mg achieved headache response (no or mild pain) at 2 and 4 hours post-dose compared with placebo.

    • Trial 1

      • Imitrex 25mg: 52%a at 2hrs and 67%a at 4hrs

      • Imitrex 50mg: 61%a,b at 2hrs and 78%a,b at 4hrs

      • Imitrex 100mg: 62%a,b at 2hrs and 79%a,b at 4hrs

      • Placebo: 27% at 2hrs and 38% at 4hrs

      • a P <.05 in comparison with placebo; b P <.05 in comparison with 25mg
    • Trial 2

      • Imitrex 25mg: 52%a at 2hrs and 70%a at 4hrs

      • Imitrex 50mg: 50%a at 2hrs and 68%a at 4hrs

      • Imitrex 100mg: 56%a at 2hrs and 71%a at 4hrs

      • Placebo: 26% at 2hrs and 38% at 4hrs

      • a P <.05 in comparison with placebo; b P <.05 in comparison with 25mg
    • Trial 3

      • Imitrex 25mg: 52%a at 2hrs and 65%a at 4hrs

      • Imitrex 50mg: 54%a at 2hrs and 72%a at 4hrs

      • Imitrex 100mg: 57%a at 2hrs and 78%a at 4hrs

      • Placebo: 17% at 2hrs and 19% at 4hrs

      • a P <.05 in comparison with placebo; b P <.05 in comparison with 25mg

  • Patients treated with Imitrex nasal spray had a lower incidence of photophobia, phonophobia, nausea and vomiting associated with migraine attacks.

Adult Dosage:

≥18yrs: 25–100mg once, swallow whole with fluids as soon as possible after migraine onset; may repeat dose at intervals of at least 2hrs, max 200mg/day; or single-dose tablets up to 100mg/day if injection has been used. Hepatic dysfunction: max 50mg/dose. The safety of treating an average of more than 4 headaches in a 30-day period has not been established.

Children Dosage:

<18yrs: not recommended.

IMITREX TABLETS Contraindications:

Ischemic coronary artery disease (eg, angina pectoris, silent ischemia, history of MI). Coronary artery vasospasm (eg, Prinzmetal's variant angina). Wolff-Parkinson-White Syndrome or arrhythmias associated with other cardiac conduction pathway disorders. Uncontrolled hypertension. History of stroke or transient ischemic attack (TIA). History of basilar or hemiplegic migraine. Peripheral vascular disease. Ischemic bowel disease. Severe hepatic impairment. Within 24 hours of ergot-type drugs (eg, methysergide, dihydroergotamine), or other 5-HT1 agonists. During or within 2 weeks after discontinuing MAO-A inhibitors (MAOI type A).

IMITREX TABLETS Warnings/Precautions:

Confirm diagnosis. Avoid excessive use. Exclude underlying cardiovascular disease, supervise 1st dose, and consider monitoring ECG in patients with likelihood of unrecognized coronary artery disease (eg, postmenopausal women, hypercholesterolemia, men over age 40, hypertension, obesity, diabetes, smokers, strong family history). Monitor cardiovascular function in long-term intermittent use. Peripheral vascular or colonic ischemia following other 5-HT1 agonists. Hepatic or renal dysfunction. Seizure risk. Latex allergy (Inj). Instruct patient on use of autoinjector. Elderly: not recommended. Pregnancy. Nursing mothers (avoid nursing for 12 hours after treatment).

IMITREX TABLETS Classification:

Selective 5-HT1B/1D receptor agonist.

IMITREX TABLETS Interactions:

Ergotamines, other 5-HT1 agonists, MAOIs: see Contraindications. Serotonin syndrome with SSRIs (eg, citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, sertraline) or SNRIs (eg, duloxetine, venlafaxine).

Adverse Reactions:

Tingling, warm/hot sensation, flushing; chest/neck/sinus/jaw discomfort; dizziness/vertigo, muscle pain/weakness, numbness, fatigue, drowsiness, anxiety, sweating, local reactions, seizures, colonic ischemia, drug overuse headache (discontinue if occurs), hypersensitivity reactions; rare: serious cardiac and cerebrovascular events (including fatalities), vision loss. Nasal spray: also dysgeusia, local irritation.

Note:

Register pregnant patients exposed to sumatriptan by calling (800) 336-2176.

Metabolism:

In vitro studies with human microsomes suggest that sumatriptan is metabolized by MAO, predominantly the A isoenzyme. Most of a radiolabeled dose of sumatriptan excreted in the urine is the major metabolite indole acetic acid (IAA) or the IAA glucuronide, both of which are inactive.

Drug Elimination:

After a single 6-mg subcutaneous dose, 22% ± 4% was excreted in the urine as unchanged sumatriptan and 38% ± 7% as the IAA metabolite.

Following a 6-mg subcutaneous injection into the deltoid area of the arm, the systemic clearance of sumatriptan was 1,194 ± 149 mL/min and the terminal half-life was 115 ± 19 minutes.

How Supplied:

STATdose kit (2 prefilled cartridges + 1 Pen)—1; Refills (2 prefilled cartridges)—1; Single-dose vials (6mg/0.5mL)—5; Tabs—9; Nasal spray (single dose)—6