Tobramycin and neuromuscular transmission in the rat isolated phrenic nerve-diaphragm preparation

The effects of different concentrations of tobramycin, streptomycin, neomycin and gentamicin on the rat isolated phrenic nerve-diaphragm preparation are reported. Streptomycin, neomycin and gentamicin produced dose-dependent neuromuscular blockade. Tobramycin increased the muscle response at high concentrations (6.4 X 10(-4) - 2.6 X 10(-2) mol litre-1, but had no detectable effect when used in therapeutically recommended concentrations.