Effect of steroids on the outcome of penicillin treatment in pneumococcal sepsis in splenectomized rats.

Increased morbidity in septic infections following splenectomy is a well-known phenomenon; despite antibiotic treatment the mortality rate associated with such infections is about 50%. Combined steroid-penicillin treatment of experimental pneumococcal sepsis was investigated in splenectomized Sprague-Dawley rats subjected to intravenous challenge with 200 colony-forming units (CFU) of pneumococci. Dexamethasone alone had no therapeutic effect. Benzylpenicillin alone was effective when given "early," i.e. 18 and 42 hours after challenge (0 of 10 animals killed), but not when given "late," i.e at 24 and 48 hours (10 of 14 killed). By contrast, even with "late" administration the combined treatment with dexamethasone and benzylpenicillin was effective against lethal pneumococcal sepsis (1 of 14 killed).