Table 1.
Possible challenges to implement multiple ivermectin treatments annually
| Challenge | Possible explanation | Remarks | Proposed perspectives |
|---|---|---|---|
| Increased cost |
- Reticence from drug manufacturers to provide additional huge quantities of ivermectin for free. - Increased local cost for ivermectin distribution, because of more logistical needs and multiplied labour force. |
Multiple CDTI per year would increase absolute cost, but the public health benefits for both malaria and neglected tropical diseases would be huge. |
- Secure external funding to sustain pluri-annual CDTI. - Convince drug manufacturers to continue providing the drug for free. |
| Reduced compliance |
- Fear of side effects. - Ignorance, lack of education and sensitization about CDTI. |
Most adverse effects of ivermectin are due to an initially high microfilarial density or loasis co-infection. Rarely, adverse effects may still occur outside these circumstances but often requires abnormally high drug dosages and/or frequency of administration. |
- Use a test-and-not-treat approach in co-endemic settings [16]. - Respect dosages of 150–200 μg/kg. - Educate the population on the health benefits of CDTI. - Reassure the population that side effects will decrease with subsequent doses of ivermectin, as the microfilarial density keeps reducing. |
| Drug resistance | Increased exposure to ivermectin due to a higher frequency of treatment may induce ivermectin resistance in the parasite [17]. | Polytherapy could help prevent drug resistance to a single drug. During the RIMDAMAL study for instance, ivermectin was co-administered with albendazole. |
- Monitor drug resistance. - Provide ivermectin in combination with other drugs using an integrated MDA approach [18]. |
| Drug interactions | Ivermectin can interact with a number of molecules, including anti-infectious agents [19]. | Important for drugs that are taken regularly, such as anti-epileptic drugs or antiretroviral drugs. | Individuals presenting a risk for drug interactions should not receive a multi-dose ivermectin treatment regimen. |
CDTI Community-directed treatment with ivermectin, MDA Mass drug administration, RIMDAMAL Repeat ivermectin mass drug administrations for control of malaria