Increased survival with calcium antagonists in antibiotic-treated bacteremia

This study was done to test the effectiveness of calcium antagonists on survival in a bacteremic model. Swiss albino mice were injected intraperitoneally with live Escherichia coli at an LD90 dose. When antibiotic treatment was delayed for 3 hr after E coli challenge, there was a mortality range of 30-50% for the gentamicin-treated mice and 40-60% for the cefoxitin-treated mice. A calcium antagonist, either nifedipine or verapamil, was added to this model in different dosages and at different time intervals. Nifedipine yielded a significantly lower mortality both with gentamicin and with cefoxitin. Verapamil did not affect mortality with cefoxitin but did improve survival with gentamicin. Effective dosages occur within a narrow range. The results are encouraging and call for further studies with calcium antagonists to ascertain their prospective usefulness as additives to septic shock treatment.