Botulinum Toxin Type A (Botox® ) Studies conducted at the Royal Hospital for Women (RHW), Sydney, NSW, Australia
The Department of Endo-Gynaecology, RHW has conducted two studies that have examined the effect of Botox® injected into the pelvic floor muscles of women who suffer from chronic pelvic pain and have co-existing pelvic floor muscle spasm. These two studies reported a significant benefit for this type of treatment with few side effects.
Women who participated in the pilot study (2002 – 2003) and the double-blind placebo-controlled study (2004 – 2005) are now participating in a third study: an open label longitudinal study (2005 – ongoing) to investigate the long-term response of women re- injected with Botox® over time.
Botox® is a selective neuromuscular blocking agent, acting by binding to receptor sites on motor nerve terminals, entering the nerve terminals and inhibiting the release of acetylcholine. When injected intramuscularly at therapeutic doses, Botox® produces a localized partial, but reversible chemical denervation of the muscle, resulting in localized muscle weakness or paralysis.
Clinical effects are often seen within 1 – 2 weeks of injection, and benefits typically last from 3-6 months. This long-lasting but reversible effect has made Botox ® an important tool in the management of a wide variety of neuromuscular disorders where over contraction of certain muscle groups leads to dysfunction.
