Background: Day 7 plasma concentrations of Lumefantrine which is an antimalarial drug can serve as a marker to predict malaria treatment outcome in different study populations. This study describes the prevalence, severity, factors influencing treatment outcome of malaria in pregnancy, and day 7 Lumefantrine plasma concentration therapeutic cut-off points that predicts treatment outcome in pregnant women.
Method: A total of 1,835 pregnant women in Coast region, Tanzania were screened for malaria by using malaria rapid diagnostic test. Eight nine (89) pregnant women with uncomplicated Plasmodium falciparum malaria receiving artemether-lumefantrine participated for the pharmacokinetics and pharmacodynamics study. Univariate and multivariate analysis were performed to identify factors influencing day 7 lumefantrine plasma concentrations and treatment outcome of malaria.
Results: The prevalence of malaria in pregnant women was 8.1%, of which 3.4% had severe malaria. The overall PCR-uncorrected treatment failure rate was 11.7%. Low baseline hemoglobin (<10g/dl) and day 7 Lumefantrine concentration < 600ng/ml were significant predictors of recurrent parasitaemia (RP). The cumulative risk of recurrent parasitemia was 9.9 folds higher when day 7 Lumefantrine cut-off concentration of <600ng/ml was compared to ≥600ng/ml.
Conclusion: To achieve effective therapeutic outcome, higher day 7 plasma Lumefantrine concentration ≥600ng/ml is required for pregnant patients than the previously suggested cut-off value of 175ng/ml or 280ng/ml for non-pregnant population.