Clinical use of botulinum toxin

Abstract

Botulinum neurotoxin type A inhibits the release of acetylcholine from cholinergic motor and autonomic nerves. Intramuscular injection leads to muscle relaxation, and intradermal injection reduces sweat gland secretion. The recommended dose depends on which preparation of botulinum toxin type A is used and its dilution, the size of the muscle or gland being injected, and the method used to localise the injection site. Repeat doses are usually required as the effect of the toxin wears off after 3-4 months. Therapy including stretching, splinting and strengthening may prolong the effect of muscle relaxation. Realistic goal setting before treatment is vital.