Effects of a single dose of metrifonate on the forest strain of Onchocerca volvulus in Cameroon
Fuglsang, H.; Anderson, J.
Tropenmedizin und Parasitologie 28(4): 439-446
1977
ISSN/ISBN: 0303-4208 PMID: 601853 Document Number: 120863
The general and ocular effects of a single dose of metrifonate (10 mg/kg) were studied in 15 moderately to heavily infected patients with onchocerciasis from the Cameroon rain-forest. The effects on the microfilariae followed the same pattern as that seen after diethylcarbamazine (DEC):-reduction in the number of microfilariae in the skin; mobilization of microfilariae into the urine, blood and cornea; development of globular limbal infiltrates and reactions around corneal microfilariae; itching, edema, tenderness of regional lymph nodes, fever, cough, general malaise and joint pains. The general side effects were less pronounced than after DEC therapy and no papular eruptions were seen. Metrifonate did not provoke irritation of the anterior segment of the eye, even though it was given without steroid cover. One heavily infected patient developed bronchial asthma 6 h after the metrifonate dose. Most of the patients complained of abdominal pain from 2-24 h post-treatment. The role of atropine as an antidote requires further investigation. Most of the patients had previously experienced the unpleasant side effects of a small DEC dosage and they considered that metrifonate was much more acceptable. In view of its obvious microfilaricidal effect without severe inflammatory reactions in the eye, metrifonate merits further trials in the treatment of ocular onchocerciasis in the savanna belt of West Africa. The many similarities between the effects of DEC and metrifonate on microfilariae may provide a clue to the mode of action of microfilaricidal drugs.