Albendazole does not alter bioavailability of praziquantel.Praziquantel markedly increases bioavailability of albendazole sulfoxide in fasted subjects, but much less so when albendazole is given with a meal, as recommended. None of these changesappears to have adverse consequences.
Clinical evidence,mechanism, importance and management
In a study in Sudanese men, AUC of albendazole sulfoxide (the active metabolite of albendazole), was increased 4.5-fold when a single 400mg dose of albendazole was given with praziquantel 40 mg/kg to fasting subjects. However,this difference was much less marked (only a 1.5-fold increase) when drugs were given with food (See reference number 1). The reasons for these changes and their practical consequences are not known, but increases in albendazole sulfoxide levels seemed not to cause any problems (See reference number 1). If both drugs are given with food,as may be advisable (see Albendazole + Food interaction, above), any interaction is modest. On basis of these studies there do not seem to be any obvious reasons why concurrent use of these two drugs should be avoided.
In a study,21 children treated for giardiasis were given a single 400mg dose of albendazole either alone or with a single 20-mg/kg dose of praziquantel. It was found that pharmacokinetics of albendazole were not significantly affected by praziquantel when drugs were given with 200 mL of milk, one hour after breakfast. There were wide inter-individual variations in plasma levels and AUC of active metabolite, albendazole sulfoxide, but these were similar whether albendazole was given alone or with praziquantel.(See reference number 2)
Homeida M,Leahy W, Copeland S, Ali MMM, Harron DWG. Pharmacokinetic interaction between praziquantel and albendazole in Sudanese men. Ann Trop Med Parasitol (1994) 88, 551–9.
Pengsaa K,Na-Bangchang K, Limkittikul K, Kabkaew K, Lapphra K, Sirivichayakul C, Wisetsing P, Pojjaroen-Anant C, Chanthavanich P, Subchareon A. Pharmacokinetic investigation ofalbendazole and praziquantel in Thai children infected with Giardia intestinalis. Ann Trop Med Parasitol (2004) 98, 349–57.