Decades down the line: the viability of praziquantel for future schistosomiasis treatment

Advocacy, policies and practicalities of preventive chemotherapy campaigns for African children with schistosomiasis

“…Foremost the drug is active against adult worms alone and not juvenile stages exhibiting a biphasic mode of action [83]. Being a racemate of dextro and laevo-isomers has disadvantages, for example, it is commonly held that only the laevo-isomer is active against schistosomes while the inactive dextro-isomer confers the unpleasant, bitter taste [83].…”

“…Foremost the drug is active against adult worms alone and not juvenile stages exhibiting a biphasic mode of action [83]. Being a racemate of dextro and laevo-isomers has disadvantages, for example, it is commonly held that only the laevo-isomer is active against schistosomes while the inactive dextro-isomer confers the unpleasant, bitter taste [83]. The killing mechanism of the drug is not completely known, but thought to interfere with voltage-gated Ca 2+ ion channels, damaging the adult worm tegument which then interacts with immune-dependant attack to the damaged worm surface [16].…”

Praziquantel

“…It exerts high cure rates in man even 6 months after a single or a 1-day treatment. Therefore, PZQ is ideally suited for large-scale treatment directed in controlling schistosomiasis (Andrews et al 1983;Cioli et al 2012).…”

“…Today, PZQ is used in mass treatment programs, in which every year several million people, mostly school children, are treated irrespective of a previous diagnosis of infection. When administered as a single oral dose of 40-60 mg/kg bodyweight, it exerts cure rates ranging between 60 and 90 % (Cioli et al 2012). Most importantly, even those individuals who are not completely cured have drastic reductions in the number of excreted schistosome eggs, an indication that the parasite load has been correspondingly decreased.…”

“…8.1) was discovered by a joint cooperation between Bayer AG and E. Merck in 1972 (Andrews et al 1983;Harder 2002). Over 30 years ago, PZQ was introduced in the field for chemotherapy against human schistosomiasis (Cioli et al 2012). Due to its high efficacy, excellent tolerability, and its simple way of application, this drug is useful for individual and mass treatment.…”