Erythromycin increases the maximum
plasma level and AUC of
cilostazol by 47% and 73%, respectively. Other drugs that inhibit CYP3A4 (such as cimetidine) are predicted to interact similarly.
In view of these effects the US manufacturers suggest halving the dose of
cilostazol in the presence of CYP3A4 inhibitors. However, the UK manufacturers con- traindicate CYP3A4 inhibitors, and they specifically name
cimetidine. This seems a very cautious approach.