NARATRIPTAN
| NARATRIPTAN (nar-a-trip'tan) Amerge Classifications: adrenergic antagonist; 5-ht1 serotonin agonist; Therapeutic: antimigraine; 5-ht1 serotonin agonist Prototype: Sumatriptan Pregnancy Category: C |
Availability
1 mg, 2.5 mg tablets
Action
Binds to the serotonin receptors (5-HT1D and 5-HT1B) on intracranial blood vessels, resulting in selective vasoconstriction of dilated vessels in the carotid circulation. It also inhibits the release of proinflammatory neuropeptides associated with a migraine attack.
Therapeutic Effect
Inhibits vasoconstriction of dilated vessels selectively. This results in the relief of acute migraine headache attacks.
Uses
Acute migraine headaches with or without aura.
Contraindications
Severe renal impairment (creatinine clearance <15 mL/min); severe hepatic impairment; history of ischemic heart disease (i.e., angina pectoris, MI), arteriosclerosis, cardiac arrhythmias; cardiac disease, CAD, older adults, peripheral vascular disease; cerebrovascular syndromes (i.e., strokes or TIA); uncontrolled hypertension; patients with hemiplegic or basilar migraine; hypersensitivity to naratriptan; older adults, pregnancy (category C).
Cautious Use
Cardiovascular disease; renal or hepatic insufficiency; lactation. Safety and efficacy in children <18 y are not established.
Route & Dosage
| Acute Migraine Adult: PO 1–2.5 mg; may repeat in 4 h if necessary (max: 5 mg/24 h); patients with mild or moderate renal or hepatic impairment should not exceed 2.5 mg/24 h |
Administration
Oral- Give any time after symptoms of migraine appear. If the first tablet was effective but symptoms return, a second tablet may be given, but no sooner than 4 h after the first. Do not exceed 5 mg in 24 h.
- If there is no response to the first tablet, contact physician before administering a second tablet.
- Do not give within 24 h of an ergot-containing drug or other 5-HT1 agonist.
- Store at 2°–25° C (36°–77° F); protect from light.
Adverse Effects (≥1%)
Body as a Whole: Asthenia, fatigue, malaise, pain, pressure sensation, paresthesias, throat pressure, warm/cold sensations, hot flushes. CNS: Somnolence, dizziness, drowsiness, headache, hypesthesia, decreased mental acuity, euphoria, tremor. CV: Coronary artery vasospasm, transient myocardial ischemia, MI, ventricular tachycardia, ventricular fibrillation, chest pain/tightness/heaviness, palpitations. GI: Dry mouth, nausea, vomiting, diarrhea. Respiratory: Dyspnea. Skin: Flushing.Interactions
Drug: Dihydroergotamine, methysergide, and other 5-ht1 agonists may cause prolonged vasospastic reactions; ssris have rarely caused weakness, hyperreflexia, and incoordination; maois should not be used with 5-ht1 agonists. Herbal: Gingko, ginseng, echinacea, St. John's wort may increase triptan toxicity.Pharmacokinetics
Absorption: Rapidly absorbed, 70% bioavailability. Peak: 2–4 h. Distribution: 28–31% protein bound. Metabolism: In liver. Elimination: Primarily in urine. Half-Life: 6 h.Nursing Implications
Assessment & Drug Effects
- Monitor carefully cardiovascular status following first dose in patients at risk for CAD (e.g., postmenopausal women, men over 40 y, persons with known CAD risk factors) or coronary artery vasospasms.
- Be aware that ECG is recommended following first administration of naratriptan to someone with known CAD risk factors and periodically with long-term use.
- Report immediately to the physician: chest pain, nausea, or tightness in chest or throat that is severe or does not quickly resolve.
- Obtain periodic cardiovascular evaluation with continued use.
Patient & Family Education
- Carefully review patient information leaflet and guidelines for administration.
- Contact physician immediately for any of the following: symptoms of angina (e.g., severe and/or persistent pain or tightness in chest or throat, severe nausea); hypersensitivity (e.g., wheezing, facial swelling, skin rash, or hives); or abdominal pain.
- Report any other adverse effects (e.g., tingling, flushing, dizziness) at next physician visit.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug