Preventing malaria: To take Lariam or not?

December 27, 1999
Web posted at: 9:49 AM EST (1449 GMT)

In this story: Safe and effective Use with caution RELATEDS

By Kathleen Doheny

(WebMD) -- Chills, malaise and headache could signal the flu. But in some parts of the world, those symptoms -- bringing with them the possibility of kidney failure, coma and even death -- usually mean one thing: malaria.

No vaccine for malaria is on the market yet, so people traveling to high-risk areas must make do with taking whatever precautions they can -- like wearing long sleeves and long pants to guard against mosquito bites, a common route of infection.

Travelers are also usually advised to take antimalarial drugs such as chloroquine, just in case. But some strains of the parasite Plasmodium falciparum, which causes the most serious form of malaria, have grown resistant to chloroquine. In recent years, one antimalarial drug, mefloquine, sold under the brand name of Lariam, has increasingly been prescribed.

As the use of Lariam has increased since the drug appeared on the U.S. market a decade ago, so has the controversy about its safety. Organizations such as Lariam Action USA, along with more vocal groups overseas, contend that Lariam is dangerous for some people, resulting in months or years of side effects such as violent dreams, extreme fatigue and other disruptive problems.

Officials from the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) -- along with the manufacturer, Roche Pharmaceuticals of Nutley, New Jersey -- say that the drug is safe when prescribed to appropriate patients and taken properly, and that the risk of side effects is outweighed by the benefits of avoiding malaria.

Around the world, more than 1.5 million people die of malaria each year, according to the WHO. From 1980 through 1995, the CDC received reports of 59 fatal malaria infections among U.S. civilian travelers. At-risk areas currently include large parts of Central and South America, sub-Saharan Africa, the Indian subcontinent, Southeast Asia, the Middle East, Oceania and Hispaniola.

Safe and effective

When the risk is from P. falciparum malaria, mefloquine is the drug of choice, says Hans Lobel, M.D., chief of the Malaria Surveillance Unit of the division of parasitic diseases at the CDC. He doesn't dispute that side effects can accompany the use of Lariam -- just as they can occur with any other drug. Among the most common, he says, are insomnia, anxiety and difficulty concentrating.

But Lobel adds that he has tracked more than 10,000 Peace Corps workers taking the drug and has compared the side effects of mefloquine, chloroquine, another antimalarial and a placebo, and he's found that "the frequency of adverse health effects was comparable." He estimates that about 20 million people worldwide have taken Lariam. In an update published in 1997 in the Journal of the American Medical Association, Lobel concludes that scientific studies to date suggest that a cause-and-effect relationship between mefloquine and adverse side effects is unlikely.

Charles Alfaro, a spokesman for Roche, says that serious neuropsychiatric side effects such as hallucinations are rare -- "about one in 10,000." Side effects such as nausea, dizziness and difficulty sleeping can occur, the manufacturer notes. Less common side effects -- occurring in fewer than one percent of subjects in clinical studies -- are emotional problems, abnormal slowing of the heartbeat and hair loss. Seizures have been reported, according to Roche.

Use with caution

Among those who should not take Lariam, according to the CDC and Roche, are those with a history of epilepsy or other seizure disorders, severe mental illness or other psychiatric disorders or those using prescription medication for an irregular heartbeat. Some doctors won't prescribe Lariam for those who are on antidepressant medication. A test dose before departure is often recommended.

But Jeanne Lese, a spokeswoman for Lariam Action USA in Berkeley, California, says the side effects are being underplayed. Since 1997, her group has received more than 540 reports of adverse reactions. All these side effects were, she says, significant -- "serious enough to interrupt your life." Some people told of having violent dreams every few nights; others reported such symptoms as extreme fatigue, numbness in their legs, dizziness, anxiety and depression.

Lese says the group is not totally opposed to the drug. "We want full disclosure from the manufacturer and the CDC, so patients can know what they are taking." Referring to the manufacturer, she says, "They say one in 10,000 will have a serious side effect. But they have a narrow definition of serious side effects."

Travelers wary of Lariam do have another alternative, Lobel says. They can take doxycycline, another antimalarial drug. It can be as effective as Lariam, he says, but only if travelers remember to take it daily. Lariam, on the other hand, is taken weekly. Another option, Malarone (atovaquone and proguanil), though already on the market overseas, is awaiting approval from the Food and Drug Administration in the United States, says Dick Jones, spokesman for the manufacturer, Glaxo Wellcome.