Comparative Toxicological Studies between Amikacin and Tobramycin Given Alone or with Calcium Gluconate in Rabbits

Abstract

This study consists of two experiments conducted to explore a toxicological comparison between tobramycin sulphate and amikacin sulphate, and to explore the role of calcium gluconate in antagonizing or reducing the main toxic side effects of tobramycin and amikacin like nephrotoxicity, ototoxicity and neuromuscular blockade.The first experiment was designed to study and measure the acute toxicity of these drugs by using the Up and Down method, which showed that the value of intravenous LD50 of both drugs increased almost twice as much from 154.8 to 294.8 mg/kg for tobramycin and from 437.1 to 737.1 mg/kg for amikacin after the pretreatment with calcium gluconate.The second experiment was performed on rabbits injected with selected toxic dose considered as LD50 of tobramycin and amikacin given by intravenous IV route for the observation of the neurotoxicity signs and recording their appearance time, until the observation of certain definite neurotoxic signs such as loss of righting reflex. At that time, calcium gluconate was given by slow intravenous infusion (over 5-10 minutes) at a high range of therapeutic dose 45mg/kg and the time of disappearance of neuromuscular blockade signs with the number of life and dead animal were recorded for each treatment.The results of this experiment showed that although tobramycin was more potent in inducing neurotoxic effects according to the dose used but amikacin is seems to be more efficacious in developing neurotoxic signs response according to it is short appearance and disappearance time of toxic signs after amikacin and calcium treatment, in comparison with that of tobramycin and calcium treatment.