Changes in nerve conduction velocity in the mouse after acute and chronic administration of nitroimidazoles.

The effect of the nitroimidazoles misonidazole, Ro-05-9963, RGW-608 and metronidazole on nerve conduction velocity (NCV) were measured in the anaesthetized mouse. The compounds were administered by i.p. injection either as a single dose of 1 mg/g (only 0.5 mg/g for RGW-608) or in 36 fractions of 0.15 mg/g over 18 days (only 4 fractions in 2 days for RGW-608). After single doses a reduction in nerve conduction velocity was seen with all the compounds except metronidazole, which had no significant effect. During chronic exposure, a reduction in NCV occurred towards the end of the course of injections. All compounds produced an effect, although RGW-608 was the most neurotoxic, giving the largest reduction in NCV after only 4 injections. After the end of chronic exposure to misonidazole, Ro-05-9963 and metronidazole, recovery to normal took 2-3 weeks.