sulpha- (US sulfa-).
A drug derived from sulphanilamide.
[The first element of sulphanilamide.]
Sulphanilamide (from sulphur, plus aniline, of which it is a derivative, plus amide) is a synthetic compound with antibacterial properties which is the basis of the sulphonamide (or sulpha) drugs. Though they have for many purposes been replaced by antibiotics, a substantial group of them is still in use, of which some examples are sulphacetamide, sulphadiazine, sulphadimidine, sulphamethoxazole, sulphapyridine, and sulphasalazine.