In vitro interactions of Captopril with NSAIDs

Captopril is effective in the treatment of hypertension of all grades of severity. Present paper deals with the in vitro
availability studies of captopril in presence and absence of commonly used NSAID’s likes diclofenac sodium,
flurbiprofen, mefenamic acid, meloxicam and tiaprofenic acid. Since it had been established that simultaneous
administration of both drugs may alter the antihypertensive effect of captopril. In order to find out the kinetics and
energitics of captopril in presence of NSAID’s, these studies were carried out in buffers of pH 4, 7.4 and 9 at 37ºC
and at elevated temperatures. These studies clearly indicate that most of the NSAID’s bind to captopril, forming
charge-transfer complexes revealing that the availability of captopril can be affected by the concurrent
administration of NSAID’s. Accordingly coadministration of both the drugs should be avoided.
Keywords: ACE-inhibitors; captopril-NSAID’s interactions; diclofenac sodium; flurbiprofen; mefenamic acid;
meloxicam; tiaprofenic acid; drug interaction