Taking a macrolide with a statin raises risk of statin toxicity.
Coadministering a cytochrome P450 isoenzyme 3A4 (CYP3A4)inhibiting macrolide antibiotic, such as clarithromycin or erythromycin) (but not azithromycin) with atorvastatin (Lipitor[R]), simvastatin (Zocor[R]), or lovastatin (Mevacor[R]), which are metabolized by CYP3 A4, is associated with a fourfold to 10-fold increase in statin concentrations. Statins are prescribed for lowering cholesterol.
Case reports have documented serious adverse consequences, including rhabdomyolysis (muscle injury) and death, from erythromycin-related or clarithromycin-related statin toxicity.
The Canadian researchers looked over administrative databases to assess toxicity in 144,00 older users of these statins who were also prescribed clarithromycin or erythromycin between 2003 and 2010. When compared with azithromycin, coprescription with clarithromycin or erythromycin was associated with an overall higher risk for the primary outcome of hospitalization with rhabdomyolysis within 30 days of the prescription and for the secondary outcome of all-cause mortality.
When possible, prescribing a statin with a clarithromycin or erythromycin should be avoided, particularly among older patients because of their higher risk, researchers warned.
(Source: Annals of Internal Medicine, June 18,2013.)