Antimalarial suppositories ‘buy time’ for patients

A one-off dose of an antimalarial drug in a rectal suppository can buy crucial time for patients with severe malaria who can’t easily access healthcare, say researchers.

Their study was published in the journal BioMedCentral Infectious Diseases last week (28 March).

Current WHO guidelines include pre-referral use of suppositories for malaria treatment. But the three types of antimalarial available in suppository form — artemisinin, artesunate and artemether — have never been compared for effectiveness.

The researchers pooled data from 15 trials of antimalarial suppositories on a total of 1,167 patients.

Suppositories were assessed for their ability to clear the malaria parasite Plasmodium falciparum from patients’ blood after 12 and 24 hours, with a 90 per cent reduction in parasites at 24 hours being classed as successful.

The researchers also tested whether single or multiple doses were more effective, the total dose necessary, and the safety of the suppositories.

They found that both artemisinin and artesunate were safe and cleared the parasite rapidly, with high doses more effective. There was not enough information on artemether to draw reliable conclusions.

A high initial dose is key to the success of the treatment. "It’s important to get adequate concentrations of antimalarial activity to reduce parasites fast, because every hour counts," says Melba Gomes, a researcher at the WHO Special Programme for Research and Training in Tropical Diseases in Switzerland, and co-author of the paper.

"An initial high single dose over 24 hours is enough to reduce parasite load and is in fact much easier than using lower sequential doses of the same drug during those first 24 hours," she told SciDev.Net.

"The idea is that if you give a drug early — and these patients really need an injectable drug but cannot get to one for several hours — then this might buy you the time to get your child alive to the hospital," she says.

Ron Behrens, of the Clinical Research Unit at the UK-based London School of Hygiene and Tropical Medicine, says, ″The study shows that effective and safe malaria treatment can be provided early on, either by health workers or even mothers, and may lead to a reduction in malaria deaths."

"This gives the green light for strategic planning for such interventions by both the WHO and national malaria control programmes," he adds, but acknowledges that the problem and cost of supplying the drugs remains.

Link to full paper in BioMedCentral Infectious Diseases [314kB]