We don't have synonyms for prems yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are press, pres and poems.
(n) :
Alternative form of pre-med. [An undergraduate college academic program, typically in biochemistry or related sciences, that prepares a student to pursue graduate or post-graduate studies in medicine.]
(n) :
Alternative form of pre-med. [An undergraduate college academic program, typically in biochemistry or related sciences, that prepares a student to pursue graduate or post-graduate studies in medicine.]