title: Population pharmacokinetics of dihydroartemisinin and piperaquine in pregnant and nonpregnant women with uncomplicated malaria.
abstract: Pregnant women are particularly vulnerable to malaria. The pharmacokinetic properties of antimalarial drugs are often affected by pregnancy, resulting in lower drug concentrations and a consequently higher risk of treatment failure. The objective of this study was to evaluate the population pharmacokinetic properties of piperaquine and dihydroartemisinin in pregnant and nonpregnant women with uncomplicated malaria. Twenty-four pregnant and 24 matched nonpregnant women on the Thai-Myanmar boarder were treated with a standard fixed oral 3-day treatment, and venous plasma concentrations of both drugs were measured frequently for pharmacokinetic evaluation. Population pharmacokinetics were evaluated with nonlinear mixed-effects modeling. The main pharmacokinetic finding was an unaltered total exposure to piperaquine but reduced exposure to dihydroartemisinin in pregnant compared to nonpregnant women with uncomplicated malaria. Piperaquine was best described by a three-compartment disposition model with a 45% higher elimination clearance and a 47% increase in relative bioavailability in pregnant women compared with nonpregnant women. The resulting net effect of pregnancy was an unaltered total exposure to piperaquine but a shorter terminal elimination half-life. Dihydroartemisinin was best described by a one-compartment disposition model with a 38% lower relative bioavailability in pregnant women than nonpregnant women. The resulting net effect of pregnancy was a decreased total exposure to dihydroartemisinin. The shorter terminal elimination half-life of piperaquine and lower exposure to dihydroartemisinin will shorten the posttreatment prophylactic effect and might affect cure rates. The clinical impact of these pharmacokinetic findings in pregnant women with uncomplicated malaria needs to be evaluated in larger series.
authors.affiliation: Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. joel@tropmedres.ac
authors.forename: Joel
authors.initials: J
authors.lastname: Tarning
authors.forename: Marcus J
authors.initials: MJ
authors.lastname: Rijken
authors.forename: Rose
authors.initials: R
authors.lastname: McGready
authors.forename: Aung Pyae
authors.initials: AP
authors.lastname: Phyo
authors.forename: Warunee
authors.initials: W
authors.lastname: Hanpithakpong
authors.forename: Nicholas P J
authors.initials: NP
authors.lastname: Day
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: White
authors.forename: François
authors.initials: F
authors.lastname: Nosten
authors.forename: Niklas
authors.initials: N
authors.lastname: Lindegardh
mesh_terms: D000293:Adolescent; D000328:Adult; D000962:Antimalarials / Q000008:administration & dosage / Q000493:pharmacokinetics*; D019540:Area Under Curve; D037621:Artemisinins / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001835:Body Weight / Q000502:physiology; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006207:Half-Life; D006801:Humans; D008288:Malaria / Q000378:metabolism*; D008875:Middle Aged; D002052:Myanmar; D017711:Nonlinear Dynamics; D011153:Population; D011237:Predictive Value of Tests; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000378:metabolism*; D011804:Quinolines / Q000008:administration & dosage / Q000493:pharmacokinetics*; D012984:Software; D053719:Tandem Mass Spectrometry; D013785:Thailand; D055815:Young Adult; D010879:Piperazines
chemical_list: D000962:Antimalarials; D037621:Artemisinins; D011804:Quinolines; C039060:artenimol; C034759:piperaquine; D010879:Piperazines