Mepacrine therapy in niclosamide resistant taeniasis.

OBJECTIVE: To evaluate the efficacy of mepacrine (quinacrine) in patients with niclosamide resistant Taenia saginata infection. METHODS: Eighty six cases with niclosamide resistant Taenia saginata (unresponsive to 2-8 courses of niclosamide) were treated with quinacrine (1 g) administered orally or via a nasogastric tube, and followed at 2, 4, 8 and 12 weeks for recurrence of passage of proglottids and presence of Taenia eggs in the stool examinations. Pre and post-therapy egg counts were obtained and egg viability was tested by staining with methylene blue. RESULTS: Eighty-one (94.2%) patients responded promptly with passage of the worm within 4-72 hours. The egg counts showed a drastic fall in 79 cases and a fall in viability from a median of 100% to 0% was observed. Only one patient demonstrated a relapse at 4 weeks. Gastrointestinal side effects occurred in 9 cases but were controlled easily by symptomatic therapy. CONCLUSION: We conclude that quinacrine is a safe, inexpensive, effective and generally well tolerated drug for the treatment of niclosamide resistant Taenia saginata infestations.