PROTECTIVE EFFECTS OF PIDOTIMOD AGAINST EXPERIMENTAL BACTERIAL-INFECTIONS IN MICE

Pidotimod ((R)-3-[(S)-(5-oxo-2-pyrrolidinyl)carbonyl]-thiazolidine-4-car- boxylic acid, PGT/1A, CAS 121808-62-6) protected mice against experimeental bacterial infections in different experimental models. In all tests the drug's effect was measured as protection from death. The activity of pidotimod was evident and statistically significant after 5 administrations before the bac- terial challenges. Pidotimod was active against many bacterial species infections, its active dosages ranging from 0.01 to 100 mg/kg i.p. x 5 times. Pidotimod showed against some bacterial infections a protection similar or better than those of bestatin, N-acetylmuramyl-L-Ala-D-isoGlu-OH and tuftsin. It showed high protection against bacterial infections in cyclophosphamide-immunodepressed mice. Finally, pidotimod showed an additive or synergic activity in combination with beta-lactam antibiotics (cefotaxime, ampicillin) against bacterial infections in mice.