Triple-Drug Therapy more effective in lymphatic filariasis: NEJM

A single dose of a three-drug regimen was more effective in clearing microfilariae from the blood in people diagnosed with lymphatic filariasis (also known as elephantiasis) as compared to other standard two-drug combinations previously used in the global effort to eliminate this infectious disease, a new study finds.

Results from the study, published in the journal New England Journal of Medicine show that a single dose of a three-drug regimen of ivermectin plus diethylcarbamazine plus albendazole was more effective in clearing W. bancrofti microfilariae from the blood than a single dose of a two-drug regimen of diethylcarbamazine plus albendazole, which is the standard regimen used for mass drug administration for the elimination of lymphatic filariasis outside sub-Saharan Africa.

Also Read: WHO Guideline on Mass drug administration regimens to eliminate Lymphatic Filariasis

The World Health Organization has targeted lymphatic filariasis for global elimination by 2020 with a strategy of mass drug administration.

Christopher L. King, professor of international health, medicine, and pathology at Case Western Reserve University School of Medicine and colleagues tested whether a single dose of a three-drug regimen of ivermectin plus diethylcarbamazine plus albendazole results in a greater sustained clearance of microfilariae than a single dose of a two-drug regimen of diethylcarbamazine plus albendazole and is noninferior to the two-drug regimen administered once a year for 3 years.

For the purpose, the researchers randomized 182 adults (1:1:1) in Papua New Guinea with Wuchereria bancrofti microfilaremia to receive a single dose of a three-drug regimen, a single dose of a two-drug regimen, or a two-drug regimen yearly for 3 years. The two-drug regimen included diethylcarbamazine (6 mg/kg) and albendazole (400 mg). The three-drug regimen added ivermectin (200 μg/kg). All drugs were given orally under direct observation.

Also Read: WHO recommends triple drug therapy for global elimination of lymphatic filariasis

Key Findings:

• The three-drug regimen cleared microfilaremia in 55 of 57 participants (96%) at 12 months, in 52 of 54 participants (96%) at 24 months, and in 55 of 57 participants (96%) at 36 months.


• A single dose of the two-drug regimen cleared microfilaremia in 18 of 56 participants (32%) at 12 months, in 31 of 55 participants (56%) at 24 months, and in 43 of 52 participants (83%) at 36 months.


• The two-drug regimen administered once a year for 3 years cleared microfilaremia in 20 of 59 participants (34%) at 12 months, in 42 of 56 participants (75%) at 24 months, and in 51 of 52 participants (98%) at 36 months (P=0.004 for noninferiority of the three-drug regimen vs. the two-drug regimen administered once a year for 3 years at 36 months).


• Moderate adverse events were more common in the group that received the three-drug regimen than in the combined two-drug–regimen groups (27% vs. 5%).


• There were no serious adverse events.