Here's what rhymes with phentermine.

Consider these alternatives

phen / then suppressant / present zidovudine / seen progestin / testing fen / then didanosine / seen hydralazine / seen thalidomide / side dexamethasone / testimony topiramate / late lamivudine / seen oxycodone / known antidepressant / present methylphenidate / state stavudine / seen