Lack of neurotoxicity of oral bisacetatoamminedichlorocyclohexylamine-platinum(IV) in comparison to cisplatin and tetraplatin in the rat.

Abstract

This study compared the effect on sensory nerve conduction velocity in the hind limb of chronically treated age-matched rats of a novel lipophilic p.o. platinum complex [bisacetatoamminedichlorocyclohexylamine-platinum(IV)], with that of neurotoxic platinum complexes cisplatin and tetraplatin. Tetraplatin (i.p.) first caused slowing of sensory nerve conduction (-14.4% of controls; P < 0.05) at a dose (1 mg/kg) that was free of constitutional toxicity. Cisplatin (i.p.) first caused slowing of sensory nerve conduction (-17.5% of control; P < 0.05) at a dose (2 mg/kg) approximating the maximal tolerated dose. Bisacetatoamminedichlorocyclohexylamineplatinum(IV) (p.o.) showed no slowing of sensory nerve conduction either after 20.5 weeks of treatment at a dose (25 mg/kg) approximating the maximal tolerated dose or after 6 weeks of treatment at a dose (50 mg/kg) which eventually proved intolerable. In conclusion, p.o. bisacetatoamminedichlorocyclohexylamineplatinum(IV) shows a lack of neurotoxicity compared to parenterally administered cisplatin and tetraplatin at the maximal tolerated dose in rats.