overtreat

verb

1. (transitive)To subject to excessive medical treatment, often to such an extent as to cause adverse effects.

   “The traditional physician in Astoria who overtreated me for a case of syphilis six and a half years ago to the tune of twelve penicillin shots plus three weeks' worth of penicillin pills.”

   “Also, overtreated patients become more insulin-resistant, and this gradually reverses as insulin doses are reduced.”