A new study by the London School of Hygiene and Tropical Medicine suggests that an effective way to treat pregnant women infected with malaria is with the use of older medications that have fallen out of use.

The study, which was conducted in Ghana between 2003 and 2004, separated pregnant women diagnosed with malaria into four trial branches and used different medications alone or in combination to see if any were suitable treatments. The study concluded that amodiaquine used alone or in combination with sulphadoxine-pyrimethamine (SP), was a safe and effective treatment for pregnant women.

“We did the study because it was becoming clear that treatment options were limited for pregnant women,” said Harry Tagbor, the lead researcher based in Ghana.

The World Health Organisation (WHO) says that 30 million pregnant women in Africa live in malaria-endemic areas and that 200,000 newborns die each year due to malaria during pregnancy.

Tragbor said that researchers wanted to look at locally available drugs to treat pregnant women. He said artesunate-based combination therapy (ACT), the recommended first-line treatment for patients with malaria, has rarely been tested to see if it is safe for pregnant women.

Nine hundred women participated in the Ghana trial and all were at least 16 weeks pregnant and beyond the first trimester - when the effects of medication on the fetus can be the most harmful.

“The women described some side effects, such as dizziness and general weakness, but only in the first few days of taking the medication,” said Tagbor.

Complicated malaria

Malaria in pregnant women poses a significant threat to both mother and child. Pregnant women are less immune to the parasite, which is transmitted from person to person by mosquitoes. It attacks red blood cells, causing chills and fever, and can escalate to coma or death if left untreated.

In expecting mothers, the consequences can include anaemia, spontaneous abortions and stillbirths. When a child is born to a mother with malaria, it can also have a low birth weight, which can decrease chances of survival in the first year.

Simply diagnosing malaria in pregnant women can be tricky.

“Often the women will have symptoms that they think are due to the pregnancy,” said Tagbor. The parasite can also hide in the placenta, making diagnostic tests inaccurate.

“We don’t want to lose the mothers or the babies. It is good news to know that [amodiaquine] is as efficacious as this,” said Tagbor.

He said that amodiaquine fell out of use in the early 1990’s when WHO withdrew recommendation for the drug. People were using it as a prophylaxis too frequently and experiencing side effects, such as liver toxicity and problems with their bone marrow, said Tagbor. He said that the drug should only be used as a treatment for malaria, not as a prophylaxis.

Amodiaquine was eventually re-introduced in the mid-1990’s. Researchers wanted to see if it would be a more effective treatment than chloroquine, a drug to which malarial parasites are developing resistance.

The question of creating resistance with the use of amodiaquine alone or in combination with SP concerns WHO.

“We must remember that the study was done in 2003-2004 and since then the failure of SP alone [as a treatment] is already on the increase,” said Dr. Peter Olumese, a malaria expert with WHO.

He said that the use of one drug on its own can contribute to resistance and if one effective drug is used in combination with a nearly non-effective one, it can have the same effect.

Prevention most effective

The recommended treatment for pregnant women by WHO is the use of ACT in the second or third trimester, and the use of quinine in the first trimester.

“We looked at the body of evidence and it showed no adverse effects,” said Dr. Kamini Mendis, coordinator of case management and research with WHO’s Global Malaria Programme.

She said that follow-up treatment of pregnant women is imperative so that any health issues that might arise can be documented.

WHO also recommends a preventative approach, which includes the use of insecticide-treated bednets and intermittent preventive treatment (IPT), whereby pregnant women are treated once a month for malaria during the last two trimesters of their pregnancy.

Osae Kofi, the general manager of the National Malaria Control Programme in Ghana, said that IPT has been effective there, where malaria is endemic.

“We piloted the programme in 2003 in a few districts, and now it is in all districts. Since then, we’ve seen [malaria] rates dropping” in pregnant women, he said.