5 - The discovery of ivermectin: a ‘crapshoot’, or not?

Summary

Healing is a matter of time, but it is sometimes also a matter of opportunity.

The Physician's Oath, Hippocrates (460–377 b.c.)

What is ivermectin? Chemically, and technically, ivermectin is aligned with a family of “16-membered macrocyclic lactones with a disaccharide attached at the carbon-13 position” (Campbell, 1989). Scientists at Merck, Sharp & Dohme Research Laboratories (MSDRL) in Rahway, New Jersey, initially isolated it. These molecules most closely resemble milbemycins, discovered in Japan and first thought to have toxic effects just for mites. It is now known that these drugs are effective against certain parasitic nematodes as well. Biologically, ivermectin is a broad-spectrum anthelmintic, acaricide, and insecticide.

For me, the story of this drug's discovery is an interesting tale, for a number of reasons. First, one of the folks deeply involved in it is an old friend of mine, Bill Campbell. I have known Bill for more than thirty years. Second, before I began writing this essay, I knew very little about this sort of applied research. So, I had to sit down and do some serious reading. Quite honestly, I found it to be rather intriguing. Third, I was told by a colleague of mine, who should know, that ivermectin is considered by many in the agricultural industry almost as a miracle drug, primarily because of its toxic breadth for both ecto- and endoparasitic organisms.