(British Approved Name Modified, US Adopted Name, rINNM)
Drug Nomenclature
INNs in main languages (French, Latin, Russian, and Spanish):
Synonyms: MK-0462; MK-462; Rizatriptán, benzoato deAdverse Effects and Precautions
As for Sumatriptan. Toxic epidermal necrolysis has also been reported with rizatriptan. Rizatriptan should not be used in patients with severe hepatic or renal impairment and should be given with caution to patients with mild or moderate hepatic or renal impairment.
Interactions
As for Sumatriptan.
Propranolol increases plasma-rizatriptan concentrations and it is recommended that lower doses of rizatriptan should be used in patients receiving both drugs (see Uses and Administration, below).
Pharmacokinetics
After oral doses, peak plasma-rizatriptan concentrations are obtained in about 1 to 1.5 hours or 1.6 to 2.5 hours depending on the formulation. Bioavailability is about 40 to 45%. Food may delay the time to peak plasma concentrations of the tablet formulation by about 1 hour. Plasma protein binding is low (14%). Rizatriptan is metabolised primarily by monoamine oxidase type A to the inactive indole acetic acid derivative. The active metabolite N-monodesmethyl-rizatriptan is formed to a minor degree; other minor metabolites are also produced. About 14% of an oral dose is excreted in the urine as unchanged rizatriptan, 51% as the indole acetic acid metabolite, and 1% as N-monodesmethyl-rizatriptan. The plasma half-life is about 2 to 3 hours. Distribution into milk has been found in studies in rats.
Uses and Administration
Rizatriptan 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. Rizatriptan is given as the benzoate, and doses are expressed in terms of the base; rizatriptan benzoate 14.53 mg is equivalent to about 10 mg of rizatriptan.
The usual dose in the UK of rizatriptan is 10 mg orally. If this is ineffective, a second dose should not be taken for the same attack. If symptoms recur after an initial response, a further dose of 10 mg may be taken after an interval of at least 2 hours. In the USA a dose of 5 or 10 mg is used. The recommended maximum dose in 24 hours is 20 mg in the UK and 30 mg in the USA. A reduced dose of 5 mg is recommended in patients also receiving propranolol, with the maximum dose in 24 hours reduced to 10 mg in the UK and 15 mg in the USA. It is also recommended that doses of the 2 drugs should be separated by at least 2 hours. For doses in hepatic or renal impairment, see below.
Administration in hepatic or renal impairment
In patients with mild to moderate hepatic or renal impairment, the dose of rizatriptan should be reduced to 5 mg. If the headache recurs following an initial response, a further dose of 5 mg may be taken after an interval of at least 2 hours. The recommended maximum dose in 24 hours in these patients is 10 mg in the UK. Rizatriptan should not be used in patients with severe hepatic or renal impairment.
Migraine
For comparison of the relative benefits of different triptans in migraine, see under Sumatriptan.
Single-ingredient Preparations
The symbol ¤ denotes a preparation which is discontinued or no longer actively marketed.
Argentina: Maxalt¤;
Austria: Maxalt; Rizalief;
Belgium: Maxalt;
Brazil: Maxalt;
Canada: Maxalt;
Chile: Maxalt;
Czech Republic: Maxalt;
Denmark: Maxalt;
Finland: Maxalt;
Germany: Maxalt;
Greece: Maxalt; Modinol¤;
Hungary: Maxalt;
India: Rizact;
Israel: Rizalt;
Italy: Maxalt; Rizaliv;
Mexico: Maxalt¤;
Netherlands: Maxalt;
Norway: Maxalt;
New Zealand: Maxalt;
Portugal: Maxalt;
South Africa: Maxalt;
Spain: Maxalt;
Sweden: Maxalt;
Switzerland: Maxalt;
United Kingdom: Maxalt;
United States: Maxalt;
Venezuela: Maxalt
Jennifer is a clinical pharmacologist. She helps doctors of all medical specialties choose medications. Jennifer consults about drug dosage, interactions, and side effects.