Blepharospasm, hemifacial spasm

Active Ingredient: Botulinum toxin type A

Indication for Botulinum toxin type A

Population group: only adults (18 years old or older)
Therapeutic intent: Curative procedure

For this indication, competent medicine agencies globally authorize below treatments:

1.25-2.5 Units once every 3 months


Dosage regimens

Intramuscular, between 1.25 international units botulinum toxin type A and 2.5 international units botulinum toxin type A, once every 3 months.

Detailed description

Recommended needle: Sterile, 27-30 gauge/0.40-0.30 mm needle.

Administrative guidance: Electromyographic guidance is not necessary.

Recommended dose: The initial recommended dose is 1.25-2.5 Units (0.05-0.1 ml volume at each site) injected into the medial and lateral orbicularis oculi of the upper lid and the lateral orbicularis oculi of the lower lid. Additional sites in the brow area, the lateral orbicularis and in the upper facial area may also be injected if spasms here interfere with vision.

The following diagrams indicate the possible injection sites:

Maximum dose: The initial dose should not exceed 25 Units per eye. In the management of blepharospasm total dosing should not exceed 100 Units in total every 12 weeks.

Additional information: Avoiding injection near levator palpebrae superioris may reduce the complication of ptosis. Avoiding medial lower lid injections, and thereby reducing diffusion into the inferior oblique, may reduce the complication of diplopia.

In general, the initial effect of the injections is seen within three days and reaches a peak at one to two weeks post-treatment. Each treatment lasts approximately three months, following which the procedure can be repeated indefinitely. Normally no additional benefit is conferred by treating more frequently than every three months.

At repeat treatment sessions, the dose may be increased up to two-fold if the response from the initial treatment is considered insufficient – usually defined as an effect that does not last longer than two months. However, there appears to be little benefit obtainable from injecting more than 5 Units per site.

Patients with hemifacial spasm or VIIth nerve disorders should be treated as for unilateral blepharospasm, with other affected facial muscles being injected as needed. Electromyographic control may be necessary to identify affected small circumoral muscles.

Dosage considerations

Total dosing should not exceed 100 Units in total every 12 weeks.

Active ingredient

Botulinum toxin type A

Botulinum toxin type A is a protein complex derived from Clostridium botulinum. The protein consists of type A neurotoxin and several other proteins. Under physiological conditions it is presumed that the complex dissociates and releases the pure neurotoxin. Intramuscular injection of the neurotoxin complex blocks cholinergic transport at the neuromuscular junction by preventing the release of acetylcholine. The nerve endings of the neuromuscular junction no longer respond to nerve impulses and secretion of the chemotransmitter is prevented (chemical denervation).

Read more about Botulinum toxin type A

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