In veterinary medicine, the drugs intended for the prevention of heartworm disease (Dirofilaria immitis nematode) are ivermectin, milbemycin oxime, moxidectin, and selamectin, belonging to the class of macrocyclic lactones. These drugs are effective against microfilariae (L3 and L4), presenting a filaricidal effect. Macrocyclic lactones, when administered with therapeutic regularity, are highly effective and are among the safest drugs, having low toxicity.
In humans, they are also therapeutic resources for the treatment of filariform larvae of the nematode Strongyloides stercoralis and larvae of the nematode Ascaris lumbricoides that migrate through the bloodstream to the lungs. During the pulmonary cycle, small hemorrhages are produced in the parenchyma, causing diffuse eosinophilic pneumonia or Loeffler syndrome.
The drug Ivermectin was tried in the prophylaxis and treatment of COVID-19 by few Physicians but the results were not very encouraging.In my opinion more comprehensive studies are needed to evaluate the efficacy of this parasitic drug in COVID-19 patients.