Rizatriptan Moclobemide

Rizatriptan is a 5-HTiB/id receptor agonist that is metabolized by MAO type A. In 12 young healthy volunteers, moclobemide (300 mg/day for 4 days) potentiated the hypertensive effect of acute rizatriptan (10 mg orally) (33). This was associated with a significant increase in the AUC of rizatriptan and its iV-monodesmethyl metabolite (by 2.2 and 5.3 times respectively). The authors suggested that moclobemide and rizatriptan should not be given together. 

Van Haarst AD, Van Gerven JM, Cohen AF, De Smet M, Sterrett A, Birk KL, Fisher AL, De Puy ME, Goldberg MR, Musson DG. The effects of moclobemide on the pharmacokinetics of the 5-HT1B/1D agonist rizatriptan in healthy volunteers. Br J Clin Pharmacol 1999 48(2) 190-6. 

Some of the triptans are metabolized by monoamine oxidase and they should not be used with monoamine oxidase inhibitors. This includes almotriptan (34), rizatriptan (35), sumatriptan (36), and zolmitriptan (28). The effect of moclobemide on the pharmacokinetics of almotriptan was less than with other triptans (34). 

Clinically important, potentially hazardous interactions with cimetidine, dihydroergotamine, ergot, fluoxetine, fluvoxamine, isocarboxazid, MAO inhibitors, methysergide, moclobemide, naratriptan, oral contraceptives, phenelzine, rizatriptan, sertraline, sibutramine, St John s wort, sumatriptan, tranylcypromine... 

Moclobemide markedly inhibits the metabolism of rizatriptan, and approximately doubles the bioavailability of sumatriptan. The manufacturers contraindicate these triptans with moclobemide and non-selective MAOIs. Moclobemide modestly inhibited the metabolism of zolmitriptan but had no clinically significant effect on almotriptan or frovatriptan. 

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