methotrexate has 2 distinct synonyms spread across 1 of its 1 sense. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
toxic antimetabolite that limits cellular reproduction by acting as an antagonist to folic acid; used to treat certain cancers and psoriasis and rheumatoid arthritis
Synonyms, antonyms and the broader and narrower relations for methotrexate come from Princeton University’s WordNet. Full sources and licences.