Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.

Botox (Allergan Australia)

vials containing 100 units of toxin, 0.5 mg human albumin and 0.9 ing sodium chloride as lyophilised powder

Indication: blepharospasm

Clostridium botulinum produces a neurotoxin which blocks the release of acetylcholine in cholinergic nerves.

By blocking transmission at the neuromuscular junction, the toxin causes paralysis.

Small amounts of the toxin injected into muscles cause weakness and atrophy. The muscles only recover when new nerve terminals grow, a process which takes several months.

Botulinum toxin injections have been used clinically in several conditions characterised by muscle spasm. The treatment is particularly effective (>90%) in the treatment of blepharospasm. It has been approved for use by patients over the age of 12 years with blepharospasm associated with dystonia, including benign blepharospasm and VII cranial nerve disorders (hemifacial spasm). The treatment may be repeated when the muscle recovers, but the long term effects of repeated injections are unknown.

The toxin must be injected by a practitioner with a detailed knowledge of the anatomy in the orbital region. Adverse effects can occur due to the spread of the toxin from the injection site. Ptosis is a common adverse effect.