Efficacy of myrrh in the treatment of human Schistosomiasis mansoni.

Myrrh (Mirazid) has been produced and marketed as an antischistosomal drug since 2001. The current study was designed to assess the efficacy of a commercially available product of myrrh. One hundred four individuals, infected with Schistosoma mansoni, were randomized in two groups, one for myrrh and the second for praziquantel. Treatment-whether myrrh or praziquantel-was given twice with a 3-week interval. The cure rate with myrrh was very low, 15.6% after the first treatment, and 8.9% after the second treatment. Egg reduction among uncured persons was also very low, being 17.2% after the first treatment, and 28% after the second treatment. Praziquantel cure rate was 73.7% and 76.3%, and individuals still passing S. mansoni ova after praziquantel treatment showed a substantial reduction in the geometric mean egg counts (84% and 88.2% after the first and second treatments, respectively). When 34 individuals-uncured after two myrrh treatments-were offered praziquantel in the standard dose, 32 of them stopped passing S. mansoni eggs when tested 4 weeks post-treatment. The results of the current study raise serious doubts about the antischistosomal properties of Mirazid.