Amerge

naratriptan hydrochloride

Amerge, Naramig (UK)

Pharmacologic class: Selective 5-hydroxytryptamine₁ (5-HT₁) agonist

Therapeutic class: Vascular headache suppressant, antimigraine drug

Pregnancy risk category C

Action

Binds with specific 5-HT₁ receptors in intracranial blood vessels and sensory trigeminal nerves, leading to vasoconstriction and migraine relief

Availability

Tablets: 1 mg, 2.5 mg

Indications and dosages

➣ Migraine headache

Adults: 1 or 2.5 mg P.O. as single dose; may repeat in 4 hours. Don't exceed 5 mg in 24 hours; don't use to treat more than four headaches per month.

Dosage adjustment

• Mild to moderate renal or hepatic impairment

Contraindications

• Hypersensitivity to drug or its components

• Hemiplegic or basilar headaches

• Severe renal, cardiovascular or hepatic impairment

• History of cerebrovascular or peripheral vascular conditions

• Ischemic bowel disease

• Uncontrolled hypertension

• Use of ergot-type drugs (such as dihydroergotamine) and other 5-HT₁ agonists within 24 hours

• MAO inhibitor use within past 14 days

Precautions

Use cautiously in:

• mild to moderate renal or hepatic impairment, cardiovascular risk factors

• elderly patients (not recommended)

• pregnant or breastfeeding patients

• children (safety not established).

Administration

• Know that drug does not prevent migraine.

• Give only if patient's cardiovascular status has been evaluated and determined to be safe, and if first dose can be given under supervision.

Adverse reactions

CNS: dizziness, drowsiness, malaise, fatigue, paresthesia, cerebral hemorrhage, subarachnoid hemorrhage, stroke, other cerebrovascular events

CV: significant blood pressure elevation including hypertensive crisis (rare), coronary artery vasospasm, myocardial infarction, ventricular fibrillation or tachycardia

GI: nausea, vomiting, colonic ischemia with abdominal pain, bloody diarrhea

Other: pain or pressure sensation in throat or neck, peripheral vascular ischemia, serotonin syndrome, hypersensitivity including anaphylaxis or anaphylactoid reactions

Interactions

Drug-drug. Ergot-type compounds (dihydroergotamine, methysergide): prolonged vasospastic reaction

Hormonal contraceptives: increased naratriptan blood level and effects

MAO inhibitors: increased systemic exposure to naratriptan, increased risk of adverse reactions

Selective serotonin reuptake inhibitors: weakness, hyperreflexia, incoordination Sibutramine: serotonin syndrome

Drug-herbs. S-adenosylmethionine (SAM-e), St. John's wort: increased risk of adverse serotonergic effects

Drug-behaviors. Cigarette smoking: increased naratriptan metabolism

Patient monitoring

• Maintain especially close monitoring in patients with cardiovascular risk factors (such as hypertension, hypercholesterolemia, obesity, diabetes mellitus, cigarette smoking, strong family history), postmenopausal women, and men older than age 40.

• Assess vital signs and ECG.

• Monitor neurologic status closely. Institute safety measures as needed to prevent injury.

Discontinue drug if serotonin syndrome is suspected.

Patient teaching

• Tell patient to take at first sign of headache.

• Advise patient to take second dose (if approved) at least 4 hours after first dose if headache has not gone away completely or has returned.

• Caution patient not to take more than two tablets in a 24-hour period.

Instruct patient how to recognize and immediately report signs and symptoms of stroke and other neurologic conditions, serotonin syndrome, hypersensitivity, or bloody diarrhea.

• Advise patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.

• Tell patient to avoid cigarette smoking and to discuss herb use with prescriber.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, herbs, and behaviors mentioned above.

naratriptan

(nar-a-trip-tan) naratriptan,

Amerge

(trade name)

Classification

Therapeutic: vascular headache suppressants
Pharmacologic: five ht1 agonists
Pregnancy Category: C

Indications

Acute treatment of migraine headache.

Action

Acts as an agonist at specific 5-HT₁ receptor sites in intracranial blood vessels and sensory trigeminal nerves.

Therapeutic effects

Cranial vessel vasoconstriction with resultant decrease in migraine headache.

Pharmacokinetics

Absorption: Well absorbed (70%) following oral administration.Distribution: Unknown.Metabolism and Excretion: 60% excreted unchanged in urine; 30% metabolized by the liver.Half-life: 6 hr (↑ in renal impairment).

Time/action profile (↓ migraine pain)

ROUTE	ONSET	PEAK	DURATION
PO	30–60 min	2–3 hr†	up to 24 hr

†3–4 hr during migraine attack

Contraindications/Precautions

Contraindicated in: Hypersensitivity;Ischemic heart disease or Prinzmetal's angina;Uncontrolled hypertensionWolff-Parkinson-White syndrome or other arrhythmias involving conduction pathwaysHemiplegic or basilar migraine;Stroke or transient ischemic attack;Peripheral vascular disease;Ischemic bowel diseaseSevere renal impairment (CCr <15 mL/min);Severe hepatic impairment;Should not be used within 24 hr of other 5-HT₁ agonists or ergot-type compounds (dihydroergotamine); Geriatric: Age-related ↓ in renal function and ↑ likelihood of CAD greatly ↑ risk of fatal adverse events.Use Cautiously in: Mild to moderate renal or hepatic impairment (dose should not exceed 2.5 mg/24 hr; initial dose should be ↓); Obstetric / Lactation / Pediatric: Safety not established.Exercise Extreme Caution in: Cardiovascular risk factors (hypertension, hypercholesterolemia, cigarette smoking, obesity, diabetes, strong family history, menopausal women or men >40 yr); use only if cardiovascular status has been evaluated and determined to be safe and 1st dose is administered under supervision.

Adverse Reactions/Side Effects

Central nervous system

dizziness
drowsiness
malaise/fatigue

Cardiovascular

coronary artery vasospasm (life-threatening)
mi (life-threatening)
ventricular fibrillation (life-threatening)
ventricular tachycardia (life-threatening)
myocardial ischemia

Gastrointestinal

nausea

Neurologic

paresthesia

Miscellaneous

pain/pressure sensation in throat/neck

Interactions

Drug-Drug interaction

↑ risk of serotonin syndrome when used with SSRI or SNRI antidepressants.Cigarette smoking ↑ the metabolism of naratriptan.Blood levels and effects are ↑ by hormonal contraceptives.Avoid concurrent use (within 24 hr of each other) with ergot-containing drugs (dihydroergotamine) may result in prolonged vasospastic reactions.Avoid concurrent (within 2 wk) use with MAO inhibitors ; produces ↑ systemic exposure and risk of adverse reactions to naratriptan.↑ risk of serotinergic side effects including serotonin syndrome with St. John’s wort and SAMe.

Route/Dosage

Oral (Adults) 1 or 2.5 mg; dose may be repeated in 4 hr if response is inadequate (not to exceed 5 mg/24 hr or treatment of more than 4 headaches/mo).

Availability (generic available)

Tablets: 1 mg, 2.5 mg

Nursing implications

Nursing assessment

Assess pain location, character, intensity, and duration and associated symptoms (photophobia, phonophobia, nausea, vomiting) during migraine attack.
Monitor for serotonin syndrome in patients taking SSRIs or SNRIs concurrently with naratriptan.

Potential Nursing Diagnoses

Acute pain (Indications)

Implementation

Oral: Tablets may be administered at any time after the headache starts.

Patient/Family Teaching

Inform patient that naratriptan should be used only during a migraine attack. It is meant to be used for relief of migraine attacks but not to prevent or reduce the number of attacks.
- Instruct patient to administer naratriptan as soon as symptoms of a migraine attack appear, but it may be administered any time during an attack. If migraine symptoms return, a 2nd dose may be used. Allow at least 4 hr between doses, and do not use more than 2 tablets in any 24-hr period. Do not use to treat more than 4 headaches per month.
- Advise patient that lying down in a darkened room following naratriptan administration may further help relieve headache.
- Advise patient that overuse (use more than 10 days/month) may lead to exacerbation of headache (migraine-like daily headaches, or as a marked increase in frequency of migraine attacks). May require gradual withdrawal of naratriptan and treatment of symptoms (transient worsening of headache).
- Advise patient to notify health care professional prior to next dose of naratriptan if pain or tightness in the chest occurs during use. If pain is severe or does not subside, notify health care professional immediately. If wheezing; heart throbbing; swelling of eyelids, face, or lips; skin rash; skin lumps; or hives occur, notify health care professional immediately and do not take more naratriptan without approval of health care professional. If feelings of tingling, heat, flushing, heaviness, pressure, drowsiness, dizziness, tiredness, or sickness develop, discuss with health care professional at next visit.
- Instruct patient not to take additional naratriptan if no response is seen with initial dose without consulting health care professional. There is no evidence that 5 mg provides greater relief than 2.5-mg dose. Additional naratriptan doses are not likely to be effective, and alternative medications, as previously discussed with health care professional, may be used.
- Naratriptan may cause dizziness or drowsiness. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.
- Advise patient to avoid alcohol, which aggravates headaches, during naratriptan use.
- Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications. Patients concurrently taking SSRI or SNRI antidepressants should notify health care professional promptly if signs of serotonin syndrome (mental status changes: agitation, hallucinations, coma; autonomic instability: tachycardia, labile BP, hyperthermia; neuromuscular aberrations: hyperreflexia, incoordination; and/or gastrointestinal symptoms: nausea, vomiting, diarrhea) occur.
- Caution patient not to use naratriptan if pregnancy is planned or suspected or if breast feeding. Adequate contraception should be used during therapy.

Evaluation/Desired Outcomes

Relief of migraine attack.

Amerge

(ə-mûrg′) A trademark for the drug naratriptan hydrochloride.