A randomized open-label evaluation of the antimalarial prophylactic efficacy of azithromycin-piperaquine versus sulfadoxine-pyrimethamine in pregnant Papua New Guinean women
Emerging sulfadoxine-pyrimethamine (SP) malaria parasite resistance has prompted assessment of alternatives for intermittent preventive treatment in pregnancy (IPTp).Objective: To evaluate the tolerability and prophylactic efficacy of azithromycin (AZ) plus piperaquine (PQ) in pregnant Papua New Guinean women.Study design: Open-label, randomized, parallel-group trial.Methods: 122 women (median gestation 26 [range 14-32] weeks) were randomized 1:1 to three daily doses of 1g AZ plus 960 mg PQ tetraphosphate or single-dose SP (4,500 mg sulfadoxine, 225 mg pyrimethamine) based on computer-generated block randomization. Tolerability was assessed to Day 7, and efficacy to Day 42 (when participants were returned to usual care) and at delivery.Results: Data from 119 participants (AZ-PQ n=61, SP n=58) were analyzed. Both regimens were well tolerated, but AZ-PQ was associated with more gastrointestinal side-effects (31%) and dizziness (21%). Eight women (6.7%) were parasitemic at recruitment but all were aparasitemic by 72 hours. There was no difference in blood smear positivity between AZ-PQ and SP up to Day 42 (0% versus 5.2%; relative risk (RR) (95% CI) 0.14 (0.01,2.58), P=0.18; absolute risk reduction (ARR) (95% CI) 5.2 (-1.3,11.6)%) and by the time of delivery (0% versus 8.7%; RR 0.11 (0.01,2.01), P=0.14; ARR 8.7 (-0.2,17.6)%). Of 92 women followed to parturition, 89 (97%) delivered healthy babies and there were three stillbirths (SP n=1, AZ-PQ n=2 (twins)). There was a higher mean±SD live birthweight in the AZ-PQ group (3.13±0.42 versus 2.88±0.55 kg; P=0.016 (mean difference (95% CI) 0.25 (0.02,0.48) kg).Conclusion: AZ-PQ is a promising candidate for IPTp.