Amerge (Naratriptan Hydrochloride) - Drug Interactions, Contraindications, Overdosage

DRUG INTERACTIONS

Selective Serotonin Reuptake Inhibitors/Serotonin Norepinephrine Reuptake Inhibitors and Serotonin Syndrome

Cases of life-threatening serotonin syndrome have been reported during combined use of SSRIs or SNRIs and triptans (see WARNINGS).

Ergot-Containing Drugs

Ergot-containing drugs have been reported to cause prolonged vasospastic reactions. Because there is a theoretical basis that these effects may be additive, use of ergotamine-containing or ergot-type medications (like dihydroergotamine or methysergide) and naratriptan within 24 hours is contraindicated (see CONTRAINDICATIONS).

Other 5-HT₁ Agonists

The administration of naratriptan with other 5-HT₁ agonists has not been evaluated in migraine patients. Because their vasospastic effects may be additive, coadministration of naratriptan and other 5-HT₁ agonists within 24 hours of each other is not recommended (see CONTRAINDICATIONS).

OVERDOSAGE

A patient who was mildly hypertensive experienced a significant increase in blood pressure after administration of a 10-mg dose starting at 30 minutes (baseline value of 150/98 to 204/144 mmHg 225 minutes). This event resolved after treatment with antihypertensive therapy. Oral administration of 25 mg of naratriptan in 1 healthy young male subject increased blood pressure from 120/67 mmHg pretreatment up to 191/113 mmHg at approximately 6 hours postdose and resulted in adverse events including lightheadedness, tension in the neck, tiredness, and loss of coordination. Blood pressure returned to near baseline by 8 hours after dosing without any pharmacological intervention.

Another subject experienced asymptomatic ischemic ECG changes likely due to coronary artery vasospasm approximately 2 hours following a 7.5-mg oral dose.

The elimination half-life of naratriptan is about 6 hours (see CLINICAL PHARMACOLOGY), and therefore monitoring of patients after overdose with AMERGE Tablets should continue for at least 24 hours or while symptoms or signs persist. There is no specific antidote to naratriptan. Standard supportive treatment should be applied as required. If the patient presents with chest pain or other symptoms consistent with angina pectoris, ECG monitoring should be performed for evidence of ischemia. It is unknown what effect hemodialysis or peritoneal dialysis has on the serum concentrations of naratriptan.

CONTRAINDICATIONS

AMERGE Tablets should not be given to patients with history, symptoms, or signs of ischemic cardiac, cerebrovascular, or peripheral vascular syndromes. In addition, patients with other significant underlying cardiovascular diseases should not receive AMERGE Tablets. Ischemic cardiac syndromes include, but are not limited to, angina pectoris of any type (e.g., stable angina of effort and vasospastic forms of angina such as the Prinzmetal variant), all forms of myocardial infarction, and silent myocardial ischemia. Cerebrovascular syndromes include, but are not limited to, strokes of any type as well as transient ischemic attacks. Peripheral vascular disease includes, but is not limited to, ischemic bowel disease (see WARNINGS).

Because AMERGE Tablets may increase blood pressure, they should not be given to patients with uncontrolled hypertension (see WARNINGS).

AMERGE Tablets are contraindicated in patients with severe renal impairment (creatinine clearance, < 15 mL/min) (see CLINICAL PHARMACOLOGY and DOSAGE AND ADMINISTRATION).

AMERGE Tablets are contraindicated in patients with severe hepatic impairment (Child-Pugh grade C) (see CLINICAL PHARMACOLOGY and DOSAGE AND ADMINISTRATION).

AMERGE Tablets should not be administered to patients with hemiplegic or basilar migraine.

AMERGE Tablets should not be used within 24 hours of treatment with another 5-HT ₁ agonist, an ergotamine-containing or ergot-type medication like dihydroergotamine or methysergide.

AMERGE Tablets are contraindicated in patients with hypersensitivity to naratriptan or any of the components.