Changes

===Procaine===

===Procaine===

Procaine is ester-linked, and so may cause allergic reactions to the PABA metabolite. It has a short duration of action and may be added to penicillin to reduce pain on injection.

Procaine is ester-linked, and so may cause allergic reactions to the PABA metabolite. It has an onset of action of 15-20 minutes and a duration of action of 45-60 minutes and may be added to penicillin to reduce pain on injection.

===Proxymetacaine===

===Proxymetacaine===