Erythromycin Cilostazol

CILOSTAZOL ANTIBIOTICS Cilostazol levels t by erythromycin and possibly clarithromycin Erythromycin and clarithromycin inhibit CYP3A4-mediated metabolism of cilostazol Avoid co-administration... 

When erythromycin was given to 16 healthy non-smoking male volunteers taking cilostazol, the C ax and AUC of cilostazol increased significantly by 47 and 73% respectively, and the unbound clearance of the major metabolite of cilostazol, OPC-13015, fell by about 50% (68). 

A study in 16 healthy subjeets found that erythromycin 500 mg three times daily increased the maximum plasma level and the AUC of a single 100-mg oral dose of eilostazol by 47% and 73%, respeetively. Erythromycin inhibits the eytoehrome P450 isoenzyme CYP3A4, by whieh cilostazol is metabolised, thereby raising its plasma levels. Other mae-rolide antibacterials e.g. clarithromycin (but not azithromycin) would be expected to have a similar effeet. ... 

In view of these effects the US manufacturers suggest halving the dose of cilostazol in the presence ofCYP3A4 inhibitors such as erythromycin, diltiazem, itraconazole, and ketoconazole. However, the UK manufacturers contraindicate CYP3A4 inhibitors, and they specifically name erythromycin, diltiazem, ketoconazole, cimetidine, and the protease inhibitors. Just why these recommendations differ is not clear. The US manufacturers suggest that other CYP3A4 inhibitors, such as azole anti-fungals (fluconazole, miconazole), SSRIs (fluoxetine, fluvoxamine, sertraline) and nefazodone, may also interact. ... 

---