General pharmacology of pidotimod and testing for drug interactions

Pidotimod ((R)-3-[(S)-(5-oxo-2-pyrrolidinyl) carbonyl]-thiazolidine-4-carboxylic acid, PGT/1A, CAS 121808-62-6) is a new biological response modifier. General pharmacology and interactions with some drugs were tested. The drug, at doses of 200 mg/kg i.p. and 400 mg/kg p.o., did not affect the normal behaviour, did not modify the responses to stimulation of autonomic nervous system or central nervous system. Pidotimod did not display any cardiovascular or respiratory effect up to 125 mg/kg i.v. in 3 animal species. The drug did not show antimicrobial or antifungal activities nor interact with some of the most common therapeutics (antibiotics, tolbutamide, pentobarbital, antihypertensives, chlorothiazide, warfarin, non-steroidal antiinflammatory agents). On the basis of these results pidotimod shows a safe profile; moreover it does not interact with many therapeutic agents.