Drug trials with levamisole hydrochloride and diethylcarbamazine citrate in Bancroftian and Malayan filariasis.

Seventy-eight microfilaraemic patients with Wuchereria bancrofti and Brugia malayi infections were treated with various oral levamisole hydrochloride total dosage regimes of 150 to 3,150 mg and total diethylcarbamazine citrate (DEC) of 36 and 126 mg per kg body-weight. Significant microfilaricidal and probable macrofilaricidal effects were seen at total levamisole hydrochloride dosages of 300 to 3,150 mg and the DEC dosages. The optimum dosage regime with levamisole hydrochloride recommended for treatment of microfilaraemic patients is 100 mg initially followed by 100 mg twice daily for 10 days. This dosage regime was as effective as a total oral dosage of DEC at 126 mg per kg body-weight. Side reactions were dose-dependent, mild and transient, with fever being the most common. One patient developed fits after 150 mg levamisole hydrochloride. The pathophysiology of these side reactions is discussed and it is recommended that levamisole hydrochloride, as a probable alternative for the treatment of patent and occult filariasis, should be used only under close medical supervision.