Fast forward - 1st March 2013

CONCERN that patients taking clopidogrel would not get the full benefit if they were also taking atorvastatin emerged in a 2003 study ex vivo of 44 people undergoing coronary artery stenting. 

The interaction was thought to occur due to atorvastatin competitively inhibiting clopidogrel activation by the cytochrome P450 3A4 (CYP3A4). 

The authors said simvastatin was also metabolised by CYP3A4 and was predicted to “exhibit pharmacological properties similar to those of atorvastatin”. 

Pravastatin and fluvastatin are not metabolised by this cytochrome and were not expected to alter clopidogrel activation.

At the time, lipids researcher and Associate Professor of Medicine at the University of NSW, Leon Simons, said if the observation was confirmed independently it could have important implications but would not change clinical practice unless the findings were replicated in a prospective, randomised trial.