Well here's a movie I haven't thought of in 20 years...
I honestly don't know that I ever would have remembered the title, but I happened to be looking at Kelly Bishop's list of work, saw it, and a lightbulb went off! I can remember watching this on HBO or Cinemax in the 80's - but I have to admit, the thing that has stuck with me after 20 years is the guy with the ants crawling all over him. Blech.
I don't think I'd buy it on DVD, but if I saw it on SciFi, I'd give it a look for "old time's sake".