# Activity of antifilarial drugs on microfilaremia in the treatment of loiasis: a systematic review

## TL;DR

This review evaluates how well different antifilarial drugs reduce microfilaremia in loiasis, highlighting their effectiveness and safety for patients with high parasite levels.

## Contribution

The study systematically compares the efficacy and safety of various antifilarial drugs for treating loiasis, focusing on microfilaremia reduction.

## Key findings

- Albendazole and mebendazole showed up to 98–100% microfilaremia reduction with extended treatment.
- Ivermectin and diethylcarbamazine achieved rapid high efficacy but raised safety concerns for hypermicrofilaremic individuals.
- Optimized treatment regimens and broader clinical outcomes need further research.

## Abstract

Loiasis, caused by the nematode/filaria Loa loa, presents a major health burden in Central and West Africa. Despite the growing recognition of loiasis’ medical significance, current antifilarial drugs remain inadequate in terms of efficacy and safety, particularly for individuals with hypermicrofilaremia. This systematic review aims to evaluate the efficacy of antifilarial treatment regimens for reducing L. loa microfilaremia and provide guidance on treatment strategies.

A systematic review was conducted to evaluate the efficacy of antifilarial treatment regimens on reducing L. loa microfilaremia. Data on the percentage reduction of microfilaremia from baseline to nadir were extracted for each treatment regimen.

A total of 27 studies were included in the review, with treatment regimens involving albendazole (ALB), mebendazole (MBZ), ivermectin (IVM), diethylcarbamazine (DEC), levamisole, imatinib, and moxidectin, among others. ALB and MBZ showed dose- and duration-dependent efficacy, with extended treatment leading to up to a 98–100% microfilaremia reduction. IVM showed a dose-dependent effect, with single doses of 200–400 µg/kg reducing microfilaremia by 88–92%. DEC exhibited high efficacy, achieving up to a 100% microfilaremia reduction.

Antifilarial drug efficacy against L. loa microfilaremia varies by dosage and treatment duration, with IVM and DEC demonstrating rapid, high efficacy but presenting safety concerns for hypermicrofilaremic individuals. ALB and MBZ show efficacy with extended treatment but are slower acting. Further research is needed to optimize treatment regimens and assess clinical outcomes beyond microfilaremia reduction.

The online version contains supplementary material available at 10.1186/s13071-025-07189-w.