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 naratriptan 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.^[1]

Adapted from the FDA Package Insert.

Template:Antimigraine preparations