Comparison of neuromuscular effects and acute toxicity of some aminoglycoside antibiotics

The correlation between acute toxicity and the effects occurring at neuromuscular junction level of some aminoglycoside antibiotics was investigated. Netilmicin (Sch 20569), sisomicin, gentamicin and kanamycin were administered i.v. in the rat and the following effects were studied: neuromuscular blocking activity (sciatic-gastrocnemius preparation), and acute toxicity evaluation. Neuromuscular blocking effects were found to be well correlated to acute toxicity data for all test-antibiotics. Comparison of results gave a sequence of relative potency which was as follows: netilmicin = sisomicin greater than gentamicin greater than kanamycin. Our findings confirmed that both respiratory failure, reporter as a side effect of the clinical use of aminoglycosides, and experimental toxicity follow the neuromuscular block.