Migraine and headache:

Indications for: AMERGE

Acute treatment of migraine with or without aura. 

Limitations of Use:

Use only after a clear diagnosis of migraine has been established. Not indicated for the prevention of migraine attacks. Safety and effectiveness of Amerge have not been established for cluster headache.

Clinical Trials:

The efficacy of Amerge in the acute treatment of migraine headaches was evaluated in 3 randomized, double-blind, placebo-controlled trials in adult patients (Trials 1, 2, 3). 

In all studies, patients were instructed to treat at least 1 moderate to severe headache. Headache response, defined as a reduction in headache severity from moderate or severe pain to mild or no pain, was assessed up to 4 hours after dosing. Associated symptoms such as nausea, vomiting, photophobia, and phonophobia were also assessed. 
Maintenance of response was assessed for up to 24 hours postdose. 
A second dose of Amerge or other rescue medication to treat migraines was allowed 4-24 hours after the initial treatment for recurrent headache. 

In all 3 trials, the percentage of patients achieving headache response 4 hours after treatment, the primary outcome measure, was significantly greater among patients receiving Amerge compared with those who received placebo.

In all trials, response to 2.5 mg was numerically greater than response to 1 mg and in the largest of the 3 trials, there was a statistically significant greater percentage of patients with headache response at 4 hours in the 2.5-mg group compared with the 1-mg group. The results are summarized below.

  • Trial 1:
    • Amerge 1 mg (n=491) = 50% (P <0.05 compared with placebo)
    • Amerge 2.5 mg (n=493) = 60% (P <0.05 compared with placebo)
    • Placebo (n=395) = 34%
  • Trial 2:
    • Amerge 1 mg (n=491) = 52% (P <0.05 compared with placebo)
    • Amerge 2.5 mg (n=493) = 66% (P <0.05 compared with placebo and compared with 1 mg)
    • Placebo (n=395) = 27%
  • Trial 3:
    • Amerge 1 mg (n=491) = 54% (P <0.05 compared with placebo)
    • Amerge 2.5 mg (n=493) = 65% (P <0.05 compared with placebo)
    • Placebo (n=395) = 32%

There is no evidence that doses of 5 mg provided a greater effect than 2.5 mg. There was no evidence to suggest that treatment with Amerge was associated with an increase in the severity or frequency of migraine attacks. The efficacy of Amerge was unaffected by presence of aura; gender, age, or weight of the subject; oral contraceptive use; or concomitant use of common migraine prophylactic drugs (eg, beta-blockers, calcium channel blockers, tricyclic antidepressants). There was insufficient data to assess the impact of race on efficacy.

Adult Dosage:

≥18yrs: 1mg or 2.5mg with fluids; may repeat once after 4hrs; max 5mg/24hrs. The safety of treating, on average, more than 4 headaches in a 30-day period has not been established. Mild to moderate renal or hepatic impairment: initially 1mg; max 2.5mg/24hrs.

Children Dosage:

<18yrs: not recommended.

AMERGE Contraindications:

Ischemic coronary artery disease (angina pectoris, history of MI, or documented silent ischemia) or vasospasm, including Prinzmetal's angina. Wolff-Parkinson-White syndrome. Arrhythmias associated with other cardiac accessory conduction pathway disorders. History of stroke, TIA, or basilar or hemiplegic migraine. Peripheral vascular disease. Ischemic bowel disease. Uncontrolled hypertension. Within 24hrs of other 5-HT1 agonists or ergot-type drugs. Severe renal or hepatic impairment.

AMERGE Warnings/Precautions:

Confirm diagnosis. Exclude underlying cardiovascular disease, supervise 1st dose, and consider monitoring ECG in patients with likelihood of unrecognized coronary disease (eg, increased age, hypertension, obesity, diabetes, smokers, strong family history). Monitor cardiovascular function in long-term intermittent use. Discontinue if arrhythmias, cerebrovascular events, or serotonin syndrome occur. Possible peripheral or GI vascular ischemia, splenic infarction, or Raynaud's syndrome following use of 5-HT1 agonists. Monitor BP during treatment. Hepatic or renal dysfunction. Elderly (monitor). Pregnancy. Nursing mothers.

AMERGE Classification:

Selective 5-HT1B/1D receptor agonist.

AMERGE Interactions:

Methysergide, other ergotamines, or other 5-HT1 agonists: see Contraindications. Serotonin syndrome with SSRIs, SNRIs, TCAs, or MAOIs.

Adverse Reactions:

Paresthesias, nausea, dizziness, drowsiness, malaise/fatigue, throat/neck symptoms (pain, pressure, tightness), drug overuse headache (discontinue if occurs); rare: serious cardiac events, anaphylactoid reactions.

Note:

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

Metabolism:

In vitro, naratriptan is metabolized by a wide range of cytochrome P450 isoenzymes into a number of inactive metabolites. 

Drug Elimination:

Naratriptan is predominantly eliminated in urine, with 50% of the dose recovered unchanged and 30% as metabolites in urine. The mean elimination half-life of naratriptan is 6 hours.

Generic Drug Availability:

YES

How Supplied:

Tabs—9