The toxicological profile of praziquantel in comparison to other anthelminthic drugs.

The toxicity data on praziquantel, effective against trematodes and cestodes, on the schistosomicides hycanthone, metrifonate, niridazole, and oxamniquine, and on albendazole, effective against cestodes and nematodes, are discussed. Praziquantel's efficacy in neurocysticercosis treatment has been well established. Recently, therapy of brain cysticercosis with albendazole was reported as well. For hycanthone, metrifonate, niridazole, and oxamniquine a mutagenic potential was demonstrated, at least in bacterial systems. Hycanthone and niridazole affect reproductive functions and are carcinogenic in animals. As not many safety data on albendazole have been published, it is possible only to deduce a teratogenic risk and--in rare cases--a hepatotoxic potential. Its capacity to induce cytochrome P-448 needs further elucidation, because the activation of drugs and chemicals by this monooxygenase isozyme may produce toxic or even carcinogenic metabolites. Likewise, it needs to be established, how possible effects on the intracellular tubulin system, which are known to occur with related benzimidazoles, affect the safety profile of this drug. From the toxicological point of view, praziquantel is the most promising drug, because it lacks systemic toxicity after repeated administration of daily doses of up to 1000 or 180 mg/kg to rats and dogs, respectively, and after lifetime bioassays with rats and Syrian hamsters. It does not affect reproduction, and is devoid of any mutagenic or carcinogenic potential.