July 1998

Vol. 13, No. 7     What's this?

New Malaria Drugs

a replacement for Lariam

from the July, 1998 issue of Undercurrent  

If divers travel abroad the risk of malaria is a factor that should be considered. While a few cases appear in Central America, the highest risk occurs in Africa, Asia and the South Pacific where strains have become resistant to common preventatives like Chloroquine. In these areas, the current substitute is Lariam (mefloquine). If you have followed any of our past articles on malaria you know that we’ve been less than pleased with Lariam and its side effects. New hope may be on the horizon.

A vaccine is under study by Navy researchers. It consists of purified genes, known as “naked DNA,” which are injected directly into muscle tissue. The tissue absorbs a small amount of the DNA and follows its instructions to manufacture a small amount of the protein specified by the malaria gene. The presence of the malarial protein, in turn, stimulates a strong immune response in the patient without risk of contracting the disease itself. Navy researchers plan to publish their study on the new vaccine soon, but it must still undergo massive testing before it becomes publicly available.

Another new drug, however, is already licensed in the United Kingdom and may be available in the U.S. sometime next year. The new drug, called Malarone, is apparently more effective than Lariam, to which several strains of falciparum malaria are becoming increasingly resistant. Doctors in the U.K. report a 98% cure rate with Malarone, which contains two separate compounds, proguanil and atovaquone, each of which targets a different stage in the protozoa’s reproductive cycle within human red blood cells.

Malarone, manufactured in the U.K. by Glaxo Wellcome, has only mild and transitory side effects and does not cause the side effects of Lariam , which include dizziness, insomnia, disturbing dreams, nausea, and, in rare cases, neuropsychological problems. It’s also taken once a day, which is easier to remember than Lariam’s once-a-week dosing, and it can be stopped seven days after departure, much sooner than the two-to-four week post-travel treatment Lariam now requires.

Of course, scientists have imagined that they had the upper hand against malaria before, most notably when widespread DDT usage in the 50s and 60s made the battle seem almost over. Both Anopheles mosquitoes and the Plasmodia protozoa have proven extremely resistant and adaptive. This time, however, the parasite may have to change the protein codes in its DNA.

— John Q. Trigger