(British Approved Name Modified, US Adopted Name, rINNM)
Drug Nomenclature
INNs in main languages (French, Latin, Russian, and Spanish):
Synonyms: GR-85548A; GR-85548X (naratriptan); Naratriptán, hidrocloruro dePharmacopoeias. In US.
The United States Pharmacopeia 31, 2008, and Supplements 1 and 2 (Naratriptan Hydrochloride). A white to pale yellow solid. Soluble in water. Store in airtight containers at a temperature not exceeding 30°.
Adverse Effects and Precautions
As for Sumatriptan.
Naratriptan should not be used in patients with severe hepatic or renal impairment (creatinine clearance less than 15 mL/minute) and should be used with caution in mild or moderate renal or hepatic impairment. Patients with hypersensitivity to sulfonamides may theoretically exhibit a similar reaction to naratriptan.
Medication-overuse headache
For a report of an association between naratriptan and medication-overuse headache, see under Adverse Effects of Sumatriptan.
Interactions
As for Sumatriptan.
Pharmacokinetics
After oral doses, peak plasma-naratriptan concentrations occur at 2 to 3 hours, and bioavailability is reported to be 63% in men and 74% in women. Plasma protein binding is about 29%. Naratriptan undergoes some hepatic metabolism by a wide range of cytochrome P450 isoenzymes. It is mainly excreted in the urine with 50% of a dose being recovered as unchanged drug and 30% as inactive metabolites. The elimination half-life is 6 hours, and is significantly prolonged in patients with renal or hepatic impairment.
Distribution into milk has been found in studies in rats.
Uses and Administration
Naratriptan is a selective serotonin (5-HT1) agonist with actions and uses similar to those of sumatriptan. It is used for the acute treatment of the headache phase of migraine attacks. It should not be used for prophylaxis. It is given orally as the hydrochloride, and doses are expressed in terms of the base; naratriptan hydrochloride 1.11 mg is equivalent to about 1 mg of naratriptan.
The recommended dose of naratriptan in the UK is 2.5 mg, and in the USA it is 1 or 2.5 mg. If no response is obtained with the initial dose, a second dose should not be taken for the same attack. If symptoms recur after an initial response, the dose may be repeated after an interval of 4 hours, to a maximum of 5 mg in any 24-hour period. For doses in hepatic or renal impairment see below.
Administration in hepatic or renal impairment
Naratriptan is contra-indicated in patients with severe hepatic or severe renal impairment (creatinine clearance less than 15 mL/minute). In patients with mild to moderate hepatic or renal impairment, the recommended maximum dose in 24 hours is 2.5 mg and a lower starting dose should be considered.
Migraine
For comparison of the relative benefits of different triptans in migraine, see under Sumatriptan.
Preparations
The United States Pharmacopeia 31, 2008, and Supplements 1 and 2: Naratriptan Tablets.
Single-ingredient Preparations
Argentina: Naramig;
Australia: Naramig;
Austria: Antimigrin; Naramig;
Belgium: Naramig;
Brazil: Naramig;
Canada: Amerge;
Chile: Naramig;
Czech Republic: Naramig;
Denmark: Naragran;
Finland: Naramig;
France: Naramig;
Germany: Naramig;
Greece: Naramig;
Hungary: Naramig;
Israel: Naramig;
Mexico: Naramig¤;
Netherlands: Naramig;
Norway: Naramig;
New Zealand: Naramig;
Portugal: Naramig;
Russia: Naramig (Нарамиг);
South Africa: Naramig;
Singapore: Naramig;
Spain: Colatan; Naramig;
Sweden: Naramig;
Switzerland: Naramig;
Thailand: Naramig¤;
United Kingdom: Naramig;
United States: Amerge
Jennifer is a clinical pharmacologist. She helps doctors of all medical specialties choose medications. Jennifer consults about drug dosage, interactions, and side effects.