title: Pharmacokinetics of praziquantel in patients with opisthorchiasis.
abstract: The pharmacokinetics of praziquantel was investigated in 9 Thai male patients with asymptomatic opisthorchiasis (stool positive) and 9 patients (6 males, 3 females) with moderately advanced infection (hepatomegaly). The geometric means of the pretreatment Opisthorchis viverrini egg count in these patients were 2,950 vs 4,468 eggs per gram of stool. The results indicate the impairment of metabolism of praziquantel in the moderately advanced stage opisthorchiasis. The pharmacokinetics of the drug in these patients during the acute infection was markedly altered when compared with that after recovery and in patients with early stage of the infection. The clearance rate (Cl/f) was significantly reduced [medians and ranges of 106 (43-242) vs 192 (112-692) and 171 (133-427) ml/min/kg] and the t1/2z and MRT were prolonged [t1/2z: 3.8 (2.0-6.2) vs 2.7 (1.7-4.3) and 2.3 (1.7-2.8) hours; MRT: 6.2 (3.2-11.0) vs 4.6 (2.7-6.2) and 4.5 (2.9-5.1) hours]. In addition, AUCo-alpha was significantly greater [6.0 (2.5-15.6) vs 3.5 (0.6-6.0) and 3.9 (1.6-5.0) micrograms hour/ml].
authors.affiliation: Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: K
authors.initials: K
authors.lastname: Na Bangchang
authors.forename: J
authors.initials: J
authors.lastname: Karbwang
authors.forename: S
authors.initials: S
authors.lastname: Pungpak
authors.forename: B
authors.initials: B
authors.lastname: Radomyos
authors.forename: D
authors.initials: D
authors.lastname: Bunnag
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008099:Liver / Q000378:metabolism*; D008111:Liver Function Tests; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D009889:Opisthorchiasis / Q000188:drug therapy* / Q000378:metabolism / Q000469:parasitology; D010270:Parasite Egg Count; D011223:Praziquantel / Q000493:pharmacokinetics* / Q000627:therapeutic use*
chemical_list: D011223:Praziquantel