Seven randomized studies in healthy volunteers have investigated interactions between
zolmitriptan (
Zomig, formerly
311C90), a 5HT1B/1D agonist for acute
migraine therapy, and selected drugs with which there was a possibility of interaction or a likelihood of concurrent use. Co-administration of oral
dihydroergotamine,
ergotamine,
pizotifen,
fluoxetine,
paracetamol (
acetaminophen)/
metoclopramide or
selegiline had no clinically significant effects on the pharmacokinetics of
zolmitriptan or its metabolites, although small changes were observed in some cases. Co-administration of
propranolol resulted in a 56% increase in the area under the plasma concentration-time curve (AUC) of
zolmitriptan and a 11% decrease in the AUC of the active metabolite
183C91. However, these pharmacokinetic changes are unlikely to be relevant at lower clinical doses.
Moclobemide, a
monoamine oxidase A (
MAO-A) inhibitor, decreased the clearance of
zolmitriptan and, in particular,
183C91. This suggests that
MAO-A is involved in the metabolism of
183C91 and it may be prudent to limit the daily
zolmitriptan dose in
migraine patients maintained on a
MAO-A inhibitor. The clinically insignificant blood pressure increases produced by
zolmitriptan, and the tolerability profile of this agent, were unaffected by any of the concomitant medications. Clinically significant interactions between
zolmitriptan and commonly co-prescribed antimigraine
therapies are unlikely.