It’s one of the few drugs that I’d consider running through a full course of, at least once a year, just in case.
I take a single dose quarterly. In one of the discussions on Ivermectin, perhaps here, someone pointed out that humans are about the only mammal humans have contact with that don’t have a regular anti-parasitical. Dogs, cats, cattle, you name it, it probably is given a dewormer every now and then. Given the overall safety of the drug, this really resonated with me. And I don’t mind the taste of the Durvet apple flavored paste, which is cheap. So yeah, quarterly for me.