Migraine and headache:

Indications for: IMITREX INJECTION

Acute treatment of migraine or cluster headaches.

Limitations of Use:

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

Clinical Trials:

Migraine (Study 1)

  • Study 1 compared 6 different doses of Imitrex Injection (n=30 each group) to placebo (n=62) in a single-attack, parallel-group design. The efficacy outcome was the percentage of patients with relief at 10 minutes, 30 minutes, 1 hour, and 2 hours, defined as the reduction of moderate or severe pain to no or mild pain after dosing without use of rescue medication.

  • Results showed that a greater percentage of patients treated with Imitrex Injection 1mg through 8mg achieved adequate relief compared with placebo:

    • Placebo: 5% at 10min; 15% at 30min; 24% at 1hr; 21% at 2hrs

    • Imitrex 1mg: 10% at 10min; 40% at 30min; 43% at 1hr; 40% at 2hrs

    • Imitrex 2mg: 7% at 10min; 23% at 30min; 57% at 1hr; 43% at 2hrs

    • Imitrex 3mg: 17% at 10min; 47% at 30min; 57% at 1hr; 60% at 2hrs

    • Imitrex 4mg: 13% at 10min; 37% at 30min; 50% at 1hr; 57% at 2hrs

    • Imitrex 6mg: 10% at 10min; 63% at 30min; 73% at 1hr; 70% at 2hrs

    • Imitrex 8mg: 23% at 10min; 57% at 30min; 80% at 1hr; 83% at 2hrs

Migraine (Study 2 and Study 3)

  • In Studies 2 and 3, Imitrex Injection 6mg was compared with placebo in 1104 patients with moderate or severe migraine pain. Headache relief was defined by a reduction in pain from severe or moderately severe to mild or no headache.

  • 70% of patients treated with Imitrex Injection 6mg achieved headache relief within 1 hour. Approximately 82% and 65% of patients treated with Imitrex 6mg had headache relief and were pain free within 2 hours, respectively.

  • Patients treated with Imitrex experienced relief of photophobia, phonophobia, nausea and vomiting associated with migraine attacks.

Cluster Headache (Study 4 and Study 5)

  • The efficacy of Imitrex Injection 6mg was evaluated in 2 randomized, double-blind, placebo-controlled, 2-period crossover trials (Studies 4 and 5). Patients were instructed to treat a moderate to very severe headache within 10 minutes of onset. Headache relief was defined by a reduction in headache severity to mild or no pain.

  • In Study 4, a greater proportion of patients treated with Imitrex 6mg achieved pain relief at 5min, 10min, and 15min post-injection compared with those treated with placebo, respectively:

    • For Imitrex 6mg – 21% at 5min; 49% (P <.05) at 10min; 74% (P <.05) at 15min

    • For placebo – 8% at 5min; 10% at 10min; 26% at 15min

  • In Study 5, a greater proportion of patients treated with Imitrex 6mg achieved pain relief at 5min, 10min, and 15min post-injection compared with those treated with placebo, respectively:

    • For Imitrex 6mg – 23% (P <.05) at 5min; 49% (P <.05) at 10min; 75% (P <.05) at 15min

    • For placebo – 7% at 5min; 25% at 10min; 35% at 15min

Adult Dosage:

≥18yrs: 6mg SC (may start at lower dose if 6mg not tolerated). Reevaluate if no response. May repeat after 1 hour; max two 6mg doses in 24 hours.

Children Dosage:

<18yrs: not recommended.

IMITREX INJECTION 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 INJECTION 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).

See Also:

IMITREX INJECTION Classification:

Selective 5-HT1B/1D receptor agonist.

IMITREX INJECTION 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