sulfa vs sulpha

sulfa and sulpha both are nouns.

Word	Noun	Adjective	Verb	Adverb
sulfa	Yes	No	No	No
sulpha	Yes	No	No	No

As nouns, sulfa and sulpha are synonyms defined as:

sulfa and sulpha: antibacterial consisting of any of several synthetic organic compounds capable of inhibiting the growth of bacteria that require PABA

Other synonyms of sulfa include sulfa drug, sulfonamide.

sulfa (noun)	sulpha (noun)
antibacterial consisting of any of several synthetic organic compounds capable of inhibiting the growth of bacteria that require PABA	antibacterial consisting of any of several synthetic organic compounds capable of inhibiting the growth of bacteria that require PABA