Competition between diftalone and other drugs for the binding site(s) on human serum albumin.

The influence of a series of drugs on the binding of diftalone to human serum albumin was investigated by equilibrium dialysis. The results indicated that among the different drugs tested phenylbutazone, indomethacin, warfarin and tolbutamide were, in the order listed, the most effective in displacing diftalone from its binding site(s). Additional investigation showed that there was no consistent inhibition by diftalone of warfarin and tolbutamide binding to albumin. The information obtained might prove useful in clinical therapy whenever a combination of drugs is to be administered.