Evaluation of Synergism between the Aminoglycoside Antibiotic Streptomycin and the Cardiovascular Agent Amlodipine

Amlodipine, a cardiovascular drug, exhibited remarkable antibacterial action in vitro against 504 bacterial strains belonging to both Gram positive and Gram negative genera, as well as in vivo against a mouse-virulent bacterium. Based on such findings, the present study was undertaken to determine whether the efficacy of this non-antibiotic drug could be enhanced in the presence of any antibiotic. Twelve bacterial strains, sensitive to amlodipine as well as to 6 antibiotics, viz., benzyl penicillin, streptomycin, chloramphenicol, tetracycline, erythromycin and ciprofloxacin were chosen. Disc diffusion test with amlodipine and streptomycin revealed marked synergism between the combination, compared with their individual effects. The synergism was found to be statistically significant (p