My step-son was recently prescribed a small one off dose of ivermectin by a dermatologist to deal with a rather resistant case of scabies he acquired at a sports tournament. It took the pharmacy a couple of days to source, because signficant controls had to be put in place around prescribing it due to well, I'm just going to say what I think - the amazing capacity for the Internet to deliver dumbassery to people who…
The ironic part of this is that Ivermectin is not FDA approved for the treatment of scabies. Your doctor was prescribing it off label, based on personal judgement that it has therapeutic effect. That is not to say it doesn't work for scabies, I hope it worked for you.
https://www.medsafe.govt.nz/profs/datasheet/s/Stromectoltab....