Naratriptan hydrochloride
Naratriptan hydrochloride (Amerge)
Naratriptan hydrochloride
( NAR-ah-trip-tan)
Pregnancy Category: C Amerge (Rx)

Classification: Antimigraine drug

Action/Kinetics: Binds to serotonin 5-HT _1D and 5-HT _1B receptors. Activation of these receptors located on intracranial blood vessels, including those on arteriovenous anastomoses, leads to vasoconstriction and thus relief of migraine. Another possibility is that activation of these receptors on sensory nerve endings in trigeminal system causes inhibition of pro-inflammatory neuropeptide release. Well absorbed from GI tract. Peak levels: 2-3 hr. Unchanged drug and metabolites are primarily eliminated in urine. t 1/2, elimination: 6 hr. Excretion is decreased in moderate liver or renal impairment.

Uses: Acute treatment of migraine attacks in adults with or without aura.

Contraindications: Use for prophylaxis of migraine or for management of hemiplegic or basilar migraine. Use in clients with ischemic cardiac, cerebrovascular, or peripheral vascular syndromes; use in uncontrolled hypertension; severe renal impairment (C _CR less than 15 mL/min); severe hepatic impairment; within 24 hr of treatment with another 5-HT ₁ agonist, dihydroergotamine, or methysergide.

Special Concerns: Safety and efficacy have not been determined for use in cluster headaches or for use in children. Use with caution during lactation and with diseases that may alter the absorption, metabolism, or excretion of drugs, such as impaired renal or hepatic function.

Side Effects: Most common side effects follow. CNS: Paresthesia, dizziness, drowsiness, malaise, fatigue. GI: Nausea. Miscellaneous: Throat and neck symptoms, pain and pressure sensation.
Side effects that occurred in 0.1% to 1% of clients follow. GI: Hyposalivation, vomiting, dyspeptic symptoms, diarrhea, GI discomfort and pain, gastroenteritis, constipation. CNS: Vertigo, tremors, cognitive function disorders, sleep disorders, disorders of equilibrium, anxiety, depression, detachment. CV: Palpitations, increased BP, tachyarrhythmias, syncope, abnormal ECG (PR prolongation, QTc prolongation, ST/T wave abnormalities, premature ventricular contractions, atrial flutter, or atrial fibrillation). Musculoskeletal: Muscle pain, arthralgia, articular rheumatism, muscle cramps and spasms, joint and muscle stiffness, tightness, and rigidity. Dermatologic: Sweating, skin rashes, pruritus, urticaria. GU: Bladder inflammation, polyuria, diuresis. Body as a whole: Chills, fever, descriptions of odor or taste, edema and swelling, allergies, allergic reactions, warm/cold temperature sensations, feeling strange, burning/stinging sensation. Respiratory: Bronchitis, cough, pneumonia. Ophthalmic: Photophobia, blurred vision. ENT: Ear, nose, and throat infections; phonophobia, sinusitis, upper respiratory inflammation, tinnitus. Endocrine/Metabolic: Thirst, polydipsia, dehydration, fluid retention. Hematologic: Increased WBCs.

Overdose Management: Symptoms: Increased BP, chest pain. Treatment: Standard supportive treatment. Possible use of antihypertensive therapy. Monitor ECG if chest pain presents.

Drug Interactions: Dihydroergotamine / Prolonged vasospastic reaction; effects additive Methysergide / Prolonged vasospastic reaction; effects additive Oral contraceptives / Mean plasma levels of naratriptan Selective serotonin reuptake inhibitors / Possible weakness, hyperreflexia, and incoordination Serotonin 5-HT ₁ agonists / Additive effects

How Supplied: Tablets: 1 mg, 2.5 mg

Dosage
?Tablets Migraine headaches.
Adults: Either 1 mg or 2.5 mg taken with fluid. If headache returns or client has had only partial response, dose may be repeated once after 4 hr, for maximum of 5 mg in a 24-hr period.