By Peter Schelden
A widely available anti-parasite drug is getting a fresh look after a study published Friday shows it may be useful against COVID-19.
Usually prescribed for pinworm and nematode infections, and sometimes head lice, ivermectin (Stromectol) was shown to reduce viral colonies of COVID-19 by 5,000 times within 48 hours of a single treatment in a cell culture infected in a laboratory. This test was not performed on humans.
The medicine works on parasites by binding to their muscle and nerve cells, causing paralysis and death, said MedicineNet medical author Omudhome Ogbru, Pharm.D.
The parasites that ivermectin targets include multicellular roundworms, classified within the animal kingdom as nematodes. Viruses, on the other hand, are mostly bits of RNA or DNA wrapped in proteins. They are not animals and don't even have single cells of their own, let alone muscle and nerve cells to target.
But researchers believe ivermectin may also attack a specific protein common to many RNA viruses, which is why it seems to limit the flu and West Nile.
The authors also note that although ivermectin was shown to be safe in a single daily dose in a recent Thai study, it did not show clinical benefit for dengue fever. Dengue is caused by another RNA virus.
If the drug does prove effective for humans fighting COVID-19 infections, the study points to several potential benefits of this drug. For one, it is widely available because the WHO already lists it as an "essential medicine. The FDA approved it for human use in 1996.
For another, the drug has been established to be safe for human use, although it has not been established safe for pregnant women.
The authors conclude from the results of their study that "ivermectin is worthy of further consideration as a possible SARS-CoV-2 antiviral."
Ivermectin Interactions and Other Safety Considerations
Ivermectin has not been shown safe and effective in children who weigh less than 33 lbs (15 kg), according to Dr. Ogbru.
He adds that pregnant women should avoid ivermectin because no adequate studies have been performed on pregnant women. He says breastfeeding mothers should also avoid this medicine because it can enter breast milk in trace amounts.
If you are pregnant or nursing, you should weigh the benefits of taking this drug against the risks, in consultation with your doctor.
What Are the Side Effects of Ivermectin?
Ivermectin has several common side effects, said Dr. Ogbru. These include:
Less common side effects include:
- Low blood pressure,
- facial swelling, and
- increased heart rate.