Not enough evidence on effectiveness of the drug albendazole, alone or in combination, for killing or interrupting transmission of threadlike worms that cause lymphatic filariasis

Filariasis affects about 120 million people in more than 80 countries and is spread by mosquitoes. Adult worms take up residence in lymph channels and when paired, produce larvae that circulate in the blood. The adult worms can live in the lymph system for five years or more. The infection can cause severe disability, due to massive enlargement of limbs, genitals, and breasts. On the other hand, many infected people have no symptoms, but do contribute to the perpetuation of the infection in the community. This review of trials found insufficient evidence to say whether a single dose of the drug albendazole kills the worms, or whether, if given in combination with diethylcarbamazine or ivermectin, it enhances the killing of these worms or the larvae they produce.

Authors' conclusions: 

There is insufficient evidence to confirm or refute that albendazole co-administered with DEC or ivermectin is more effective than DEC or ivermectin alone in clearing microfilariae or killing adult worms. Albendazole combined with ivermectin appears to have a small effect on microfilaraemia, but this was not consistently demonstrated. The effect of albendazole against adult and larval filarial parasites, alone and in combination with other antifilarial drugs, deserves further rigorous research.

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Mass treatment with albendazole co-administered with another antifilarial drug is part of a global programme to eliminate lymphatic filariasis. We sought reliable evidence of the effects of albendazole on the disease and the parasite.


To summarize the effects of albendazole alone or in combination with antifilarial drugs for clinical treatment and community control of lymphatic filariasis.

Search strategy: 

We searched the Cochrane Infectious Diseases Group Specialized Register (August 2005), CENTRAL (The Cochrane Library Issue 3, 2005), MEDLINE (1966 to August 2005), EMBASE (1974 to August 2005), LILACS (1982 to August 2005), and reference lists. We also contacted researchers, the World Health Organization, and GlaxoSmithKline.

Selection criteria: 

Randomized and quasi-randomized controlled trials of albendazole alone or combined with another antifilarial drug for treating individuals with lymphatic filariasis, or for reducing transmission in endemic communities.

Data collection and analysis: 

Two authors independently assessed eligibility and trial quality, and extracted data. Authors contacted investigators for missing information or clarification.

Main results: 

Seven trials including 6997 participants (995 with detectable microfilariae) met the criteria. A comparison of albendazole and placebo detected no effect on microfilariae prevalence (920 participants; 3 trials); one trial (499 participants) reported significantly lower microfilariae density at six months. Albendazole performed slightly worse than ivermectin in two trials (436 participants). Compared with diethylcarbamazine (DEC), two small trials (56 participants) found little difference in microfilariae prevalence over an extended follow up. One larger trial (502 participants) found a statistically significant effect for DEC at six months, but none at three months.

Microfilariae prevalence and density were statistically significantly lower with the combination of albendazole and ivermectin compared with ivermectin alone in two of three trials (649 participants). Two trials compared albendazole plus DEC with DEC alone and found no statistically significant difference in microfilariae prevalence, though one trial favoured the combination at six months (risk ratio 0.62, 95% confidence interval 0.32 to 1.21; 491 participants). This trial also found a statistically significant reduction in microfilariae density.