'antianaphylactic' originates from Greek elements: 'anti-' (Greek 'anti') and 'anaphylaxis' (Neo-Greek 'anaphylaxis'), where 'anti-' meant 'against' and 'anaphylaxis' referred to 'opposite of protection' (a term coined for a hypersensitivity reaction).

'antianaphylactic' was formed in modern medical English by combining the prefix 'anti-' with 'anaphylactic' (from Neo-Greek 'anaphylaxis', coined in the early 20th century) to describe agents or actions that oppose or prevent anaphylaxis.

Initially the components signified 'against protection' in their Greek roots; over time the combined term came to mean specifically 'acting against or preventing anaphylaxis' in medical usage.