BETA BLOCKERS AND TERBINAFINE
In vitro studies suggest that terbinafine is an inhibitor of CYP2D6. It may therefore be expected to increase the plasma levels of other drugs that are substrates of this enzyme. The manufacturers suggest that the levels of some beta blockers may be raised. Carvedilol, metoprolol, nebivolol, propranolol and timolol are all metabolized, at least in part, by CYP2D6.
Until more is known it would seem wise to be aware of the possibility of an increase in adverse effects if any of these drugs is given with terbinafine and consider a dose reduction if necessary. The interaction is most likely to be of clinical significance when drugs such as metoprolol are given for heart failure.
Until more is known it would seem wise to be aware of the possibility of an increase in adverse effects if any of these drugs is given with terbinafine and consider a dose reduction if necessary. The interaction is most likely to be of clinical significance when drugs such as metoprolol are given for heart failure.