DARIFENACIN AND MACROLIDES
Erythromycin almost doubles the AUC of darifenacin by inhibiting its metabolism by CYP3A4. Other macrolides that inhibit CYP3A4 may interact similarly, see macrolide.
The US manufacturers suggests that no dosage adjustments are necessary with erythromycin, whereas the UK manufacturer suggests increasing the darifenacin dose with caution. Bear in mind the possibility of an interaction if antimuscarinic effects (dry mouth, constipation, drowsiness) are increased.
The US manufacturers suggests that no dosage adjustments are necessary with erythromycin, whereas the UK manufacturer suggests increasing the darifenacin dose with caution. Bear in mind the possibility of an interaction if antimuscarinic effects (dry mouth, constipation, drowsiness) are increased.