Sorry, I keep exposing how little I know about these drugs I take by mixing up my brand names and drug names, as well as committing spelling atrocities. I ran to the bathroom to double check.
Safeguard is Fenbenzadole 10%. This is what I take long term, PRN. It seems pretty safe and mild, but works wonderfully for me. Scab goes so far as to recommend it to women sufferers in late stage pregnancy.
Equimax is, by my understanding, more serious. It is 1.8% ivermectin and 14% praziquantel. It worked awesome during the 4 months I took it, but brought more organ pain with it.
Pyrantel pamoate is the heartworm med. I blamed it for making my heart ache when I finally stopped the protocol, though it's just speculation.
Scab has been strangely inactive on the forums for a couple of months, but he is the self-taught expert on these horse meds. So try to get corresponding with him if you are thinking about this treatment.
And again, remember that most Morgies who beat the syndrome cite radical diet/lifestyle changes, not dewormers, as the miracle cure. Magic bullets are mythical.