ABSTRACT:

Objectives: To assess the effect of vitamin B-12 complex injection on the nephrotoxicity of gentamicin.  Design: Experimental study using a pre-validated model.  Subject: Adult Swiss albino rats weighing 140-214g, Generic gentamicin sulphate injection and Vitamin B-12complex injection containing 2500mcg Cyanocobalamin, 12mg Niacinamide, 0.7 mg Folic acid  and 150 mg Ascorbic acid in twin ampoules to be combined fresh before administration.  Setting: A pharmacological research laboratory in a tertiary instituteResults: In Swiss albino rats, both 0.5mls/kg/day and 1mls/kg/day of B-12 complex injection for 5 days significantly and dose dependently exacerbated the increase in serum urea and creatinine caused by 80mg/k/day of gentamicin while both doses of B-12 complex injection given for 10 days significantly and dose dependently ameliorated the increase in serum urea and creatinine caused by 80mg/k/day of gentamicin (reversal of effect).  Conclusion: 0.5mls/kg/day of B-12 complex injection for 5 days exacerbated gentamicin nephrotoxicity while the same dose for longer duration or 1ml/kg/day of B-12 complex ameliorated the toxicity. The exacerbation is probably due to the ascorbic acid component while the reversal is probably due to the other components acting directly or through a time dependent pharmacological advantage.