Rizatriptan is mainly a substrate of monoamine oxidase A and to a smaller degree, a substrate of CYP1A2. It does not inhibit or induce CYP3A4 or other major CYP enzymes. Risk for gastrointestinal adverse events in the form of nausea, vomiting and diarrhoea motivates vigilance against insufficient intake of food, especially of carbohydrate.

Rizatriptan is a seretonin agonist.

Rizatriptan is indicated for the acute relief of migraine attacks, with or without aura. Common side effects that can be potentially porphyrinogenic through reduction in carbohydrate intake and that also can be confused with an acute porphyria attack are nausea, vomiting and diarrhoea. Other common side effects are paraesthesia and tachycardia. Some of the symptoms can be related to the underlying condition. Rizatriptan is indicated for the acute relief of migraine attacks, with or without aura. Common side effects that can be potentially porphyrinogenic through reduction in carbohydrate intake and that also can be confused with an acute porphyria attack are nausea, vomiting and diarrhoea. Other common side effects are paraesthesia and tachycardia. Some of the symptoms can be related to the underlying condition.

Rizatriptan is metabolised mainly by monoamine oxidase A (SPC). CYP1A2 is only partially involved in the metabolism (Ferrari 2003 and Tepper 2003). The metabolite N-mono-desmethyl-rizatriptan is active, but is formed only to a minor degree and does not contribute significantly to the pharmacodynamics activity of rizatriptan. 80% of an oral dose is excreted in the urine, where about 14% is excreted as unchanged drug (SPC). The half-life elimination is 2-3 hours. A clinical study showed that rizatriptan had no statistically significant effect on any of the pharmacokinetics parameters of ethinyl estradiol and norethindrone (Shadle 2000), two CYP3A4 substrates. The data therefore indicates that rizatriptan does not inhibit or induce CYP3A4. In vitro data indicates that rizatriptan inhibits CYP2D6 (SPC). No drug-drug interactions with rizatriptan as a perpetrator are observed (Interaksjoner and Interaktionsdatabasen), which indicate that rizatriptan is not an inhibitor or inducer of CYP enzymes.

Uneventful use reported in 2 patients with acute porphyria.