Aminoglutethimide increases the clearance of warfarin: higher doses seem to have a greater effect, and up to 4-fold increases in the
warfarin dosage have been needed. The effects of the interaction seem to develop over 14 days, and the interaction may persist for 2 weeks after
aminoglutethimide is stopped. Similar effects have been seen with acenocoumarol.
Monitor the INR and adjust the anticoagulant dosage accordingly if aminoglu- tethimide is started or stopped. Information about other coumarins is generally lacking but it would seem prudent to apply the same precautions with any of them.
The aminoglycosides are known to be
nephrotoxic and many of their interactions occur as a result of this effect. Due to the number of known interactions with other
nephrotoxic drugs (for examples see amphotericin, and ciclosporin), many manufacturers of other drugs with
nephrotoxic effects caution concurrent use. It is advisable to monitor
renal function in patients taking aminoglycosides, and it may be prudent to increase the frequency of this monitoring in patients taking other
nephrotoxic drugs.