BUTYL AMINO BENZOATE, A PARA-AMINOBENZOIC ACID ESTER, IS A LOCAL ANAESTHETIC, ACTS BY PREVENTING THE GENERATION AND TRANSMISSION OF IMPULSES ALONG NERVE FIBRES AND AT NERVE ENDINGS ; DEPOLARISATION AND ION-EXCHANGE ARE INHIBITED. IT MAY ALSO USED FOR CENTRAL NERVE BLOCK INCLUDING LUMBAR AND CAUDAL EPIDURAL BLOCKS.