Intermittent Preventive Treatment of Malaria in Pregnancy with Mefloquine in HIV-Infected Women Receiving Cotrimoxazole Prophylaxis: A Multicenter Randomized Placebo-Controlled Trial

Abstract

Clara Menéndez and colleagues conducted a randomized controlled trial among HIV-positive pregnant women in Kenya, Mozambique, and Tanzania to investigate the safety and efficacy of mefloquine as intermittent preventative therapy for malaria in women receiving cotrimoxazole prophylaxis and long-lasting insecticide treated nets.

Please see later in the article for the Editors' Summary

Abstract

Background

Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) is recommended for malaria prevention in HIV-negative pregnant women, but it is contraindicated in HIV-infected women taking daily cotrimoxazole prophylaxis (CTXp) because of potential added risk of adverse effects associated with taking two antifolate drugs simultaneously. We studied the safety and efficacy of mefloquine (MQ) in women receiving CTXp and long-lasting insecticide treated nets (LLITNs).

Methods and Findings

A total of 1,071 HIV-infected women from Kenya, Mozambique, and Tanzania were randomized to receive either three doses of IPTp-MQ (15 mg/kg) or placebo given at least one month apart; all received CTXp and a LLITN. IPTp-MQ was associated with reduced rates of maternal parasitemia (risk ratio [RR], 0.47 [95% CI 0.27–0.82]; p = 0.008), placental malaria (RR, 0.52 [95% CI 0.29–0.90]; p = 0.021), and reduced incidence of non-obstetric hospital admissions (RR, 0.59 [95% CI 0.37–0.95]; p = 0.031) in the intention to treat (ITT) analysis. There were no differences in the prevalence of adverse pregnancy outcomes between groups. Drug tolerability was poorer in the MQ group compared to the control group (29.6% referred dizziness and 23.9% vomiting after the first IPTp-MQ administration). HIV viral load at delivery was higher in the MQ group compared to the control group ( p = 0.048) in the ATP analysis. The frequency of perinatal mother to child transmission of HIV was increased in women who received MQ (RR, 1.95 [95% CI 1.14–3.33]; p = 0.015). The main limitation of the latter finding relates to the exploratory nature of this part of the analysis.

Conclusions

An effective antimalarial added to CTXp and LLITNs in HIV-infected pregnant women can improve malaria prevention, as well as maternal health through reduction in hospital admissions. However, MQ was not well tolerated, limiting its potential for IPTp and indicating the need to find alternatives with better tolerability to reduce malaria in this particularly vulnerable group. MQ was associated with an increased risk of mother to child transmission of HIV, which warrants a better understanding of the pharmacological interactions between antimalarials and antiretroviral drugs.

Trial registration

ClinicalTrials.gov NCT 00811421; Pan African Clinical Trials Registry PACTR 2010020001813440

Please see later in the article for the Editors' Summary

Editors' Summary

Background

Malaria, a mosquito-borne parasitic disease, kills about 600,000 people every year. Most of these deaths occur among young children living in sub-Saharan Africa but pregnant women living in Africa are also very vulnerable to malaria. Infection with malaria during pregnancy can cause severe maternal anemia (reduced red blood cell numbers), stillbirths, and pre-term and low-birthweight babies, and is responsible for the deaths of many African women and their babies. To reduce the loss of life from malaria in pregnancy, the World Health Organization (WHO) recommends that pregnant women living in Africa receive the antimalarial drug sulfadoxine-pyrimethamine (SP) at each scheduled antenatal care visit given at least a month apart (intermittent preventive treatment in pregnancy [IPTp]). In addition, WHO advises pregnant women to sleep under insecticide-treated bed nets to protect themselves from the bites of infected mosquitoes and recommends effective case management of pregnant women with malarial illness.

Why Was This Study Done?

Pregnant women living in Africa are often infected with HIV, the virus that causes AIDS. HIV infection increases both the risk and severity of malaria infection during pregnancy, and at least one million pregnancies are complicated by co-infection with malaria and HIV in sub-Saharan Africa every year. WHO recommends that HIV-positive pregnant women take cotrimoxazole (CTX) daily to prevent opportunistic infections (CTX prophylaxis [CTXp]). Unfortunately, both CTX and SP are antifolate drugs and taking two drugs of this type increases a woman's risk of developing a severe skin reaction. Moreover, although CTXp protects children and HIV-infected adults against malaria, it is not known whether CTXp alone protects HIV-infected pregnant women adequately against malaria. Thus, evaluations of alternative drugs for use in IPTp in HIV-positive pregnant women are needed. In this randomized placebo-controlled trial, the researchers study the safety and efficacy of the antimalarial drug mefloquine (MQ) in HIV-infected women receiving CTXp. A randomized, placebo-controlled trial compares outcomes among people chosen through the play of chance to receive either the drug under investigation or a “dummy” (placebo) drug.

What Did the Researchers Do and Find?

The researchers allocated 1,071 HIV-infected pregnant women from Kenya, Mozambique, and Tanzania to receive three doses of MQ (IPTp-MQ), given at least one month apart, or three doses of placebo. All the women received CTXp and were given an insecticide-treated bed net. In an intention-to-treat analysis (an analysis that considers the outcomes of all trial participants irrespective of whether they receive their allocated treatment), the prevalence of parasitemia (parasites in the blood) at delivery among women given IPTp-MQ was 3.5% whereas the prevalence among women given the placebo was 6.9%. In other words, compared to placebo, IPTp-MQ was associated with a reduced risk of maternal parasitemia. IPTp-MQ was also associated with a reduced rate of placental malaria (parasites in the placenta) and a reduced incidence of hospital admissions for non-pregnancy related causes. There was no difference in adverse pregnancy outcomes such as stillbirth between the intervention groups but drug tolerability was poorer in the MQ group than in the placebo group. Finally, in an exploratory (unplanned) according-to-protocol analysis (an analysis that only considers outcomes in trial participants who receive their allocated intervention), women in the MQ group had a higher HIV viral load at delivery than women in the control group and were nearly twice as likely to transmit HIV to their child around the time of birth.

What Do These Findings Mean?

These findings suggest that the addition of IPTp-MQ to CTXp and the use of insecticide-treated bed nets can improve malaria prevention and maternal health in HIV-infected pregnant women in Africa. However, the poor tolerability of MQ and the association of MQ treatment with both an increased HIV viral load at delivery and a higher frequency of mother-to-child-transmission of HIV when compared to placebo raise concerns about the use of MQ in IPTp. Because these last two findings came from an exploratory analysis, which is more likely to throw up a chance finding than a pre-planned analysis further studies are needed to confirm these unexpected but potentially important findings. Nevertheless, overall, the findings of this study suggest that MQ should not be recommended for IPTp in HIV-infected pregnant women in Africa and highlight the need to find alternative drugs for malaria prevention in this group of women who are particularly vulnerable to malaria.

Additional Information

Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001735.

• This study is further discussed in a PLOS Medicine Perspective by Richard Steketee.

• A related PLOS Medicine Research Article by González et al. compares the efficacy of IPTp-MQ and IPTp-SP in HIV-negative women

• Information is available from the World Health Organization on malaria (in several languages) and on malaria in pregnancy; information on IPTp and the current WHO policy recommendation on IPTp with SP are available; the 2013 World Malaria Report provides details of the current global malaria situation

• The US Centers for Disease Control and Prevention also provides information on malaria; a personal story about malaria in pregnancy is available

• Information is available from the Roll Back Malaria Partnership on all aspects of global malaria control, including information on malaria in pregnancy

• The Malaria in Pregnancy Consortium is undertaking research into the prevention and treatment of malaria in pregnancy

• MedlinePlus provides links to additional information on malaria (in English and Spanish)

• More information about the trial protocol is available