Lack of interaction between thioctic acid, glibenclamide and acarbose

Aims Thioctic acid (TA), glibenclamide and acarbose are widely used to eith er alone or concomitantly treat patients suffering from noninsulin-dependen t diabetes (NIDDM). This study systematically investigated drug-drug intera ctions between TA and glibenclamide and TA and acarbose. Methods Fourteen male and 10 female healthy volunteers participated a rando mized, open three period cross over trial (treatments A-C) followed by a fo urth period (treatment D). A baseline profile for plasma insulin and glucos e concentrations, variables which served as pharmacodynamic measures, was a ssessed before entering the trial. Treatments were A = 600 mg TA orally, B = 3.5 mg glibenclamide orally, C = 600 mg TA + 3.5 mg glibenclamide, D = 60 0 mg TA + 50 mg acarbose. Time courses of R(+)-TA and S(-)-TA as well as gl ibenclamide concentrations were measured with specific analytical methods. Results There was no clinically relevant change of TA enantiomer pharmacoki netics by glibenclamide or acarbose. Also, glibenclamide pharmacokinetics w ere not altered by TA to a clinically meaningful extent. Plasma insulin and glucose concentrations did not indicate an interaction between TA and glib enclamide or TA and acarbose. Glibenclamide had the expected effect on insu lin and glucose levels independent of comedication. There were only minor a nd short lasting adverse events with the majority being (expected) hypoglyc aemic symptoms occurring during the treatments with glibenclamide. Conclusions Coadministration of single doses of TA and glibenclamide or TA and acarbose does not appear to cause drug-drug interactions.