Phase 1 tolerability and antiamoebic activity studies with 1-methylsulphonyl-3-(1-methyl-5-nitro-2-imidazolyl)-2-imidazolidinone (Go.10213): a new antiprotozoal agent.

Go.10213, a new nitroimidazole, was studied in 12 male volunteers for tolerability and in 20 patients with intestinal amoebiasis for antiamoebic activity. Go.10213 was well-tolerated by volunteers up to a dose of 400 mg X 3. Patients also tolerated well the dose of 100-150 mg X 3 for 7 days. In two patients, there were mild and transient side-effects like headache, dizziness, fatigue, etc. No neurological side-effects were observed. There were no significant changes in blood pressure, pulse rate and ECG. The organ function tests did not show any adverse effects of Go.10213 on bone-marrow, kidney, liver, etc. Go.10213, at a dose of 150 mg X 3, showed potent antiamoebic activity in 10 patients with intestinal amoebiasis, as judged by the clinical relief, the eradication of the trophozoites and cysts of Entamoeba histolytica from stools and the healing of colonic ulcers. Go.10213, a novel nitroimidazole, may prove to be the most potent and safe agent against the protozoal infections, e.g. amoebiasis, giardiasis and trichomoniasis.