Quantification of ivermectin in veterinary products consumed off-label as a treatment for COVID-19.

The COVID-19 pandemic caused global pandemonium, and due to an unprecedented global response, the popularity and use of (veterinary) ivermectin, amongst many other conceivable 'treatments', experienced a meteoric rise. Ivermectin is a macrocyclic lactone compound belonging to the avermectin drug class and is a registered medicine in many countries, although the most common use is as veterinary medicine. In this study, a fast HPLC method was developed and validated for the quantification of ivermectin in veterinary products that were used off-label by a substantial number of people during COVID-19. Locally used veterinary products were collected as well as commercial products acquired and were tested using the newly developed method. The ivermectin content was compared to the products' label claims and it was found that all products tested contained ivermectin within acceptable limits. However, the use of veterinary products is strongly discouraged due to high dosages and administration regimens that were tested in animals and can lead to serious adverse events in humans. The presence of untested excipients and secondary actives, such as clorsulon, which can cause unknown (long-term) health impacts in humans, further adds credence to this warning.