Studies on the chemotherapy of human opisthorchiasis: effective dose of praziquantel in heavy infection.

Ninety-six patients who had heavy Opisthorchis viverrini infection were studied. Egg count per gram of faeces ranged from 10,800 to 139,000 (mean 26,044.3). Praziquantel 50 mg per kg body weight was given after a morning meal. 68 patients completed the follow up period of 60 days. The cure rate was 97.0%. The side-effects occurred in 61 patients (89.7%). The common side effects were diarrhoea, dizziness, sleepiness, epigastric pain, headache, nausea and anorexia. These side-effects were mild and transient. 62 patients (91.2%) showed clinical improvement, and 20 patients were symptom free on day 60.