Improvement in pelvic pain with botulinum toxin type A – Single vs. repeat injections
Highlights
► BOTOX is effective in reducing pain in women with pelvic floor hypertonicity. ► We examine outcomes for repeat dosing in this patient cohort. ► BOTOX was effective at reducing pain with repeat dosing. ► BOTOX was effective at reducing vaginal pressure with repeat dosing.
Introduction
Botulinum toxin type A produces localised muscle weakness or paralysis through biochemical denervation and is used for the treatment of many neuromuscular disorders, as well as chronic pelvic pain and pelvic floor overactivity (Jankovic and Brin, 1991; Maria et al., 2000; Abbott, 2009; Bjornson et al., 2007). Reduction in pain is associated with a return to normal physical activity, mood and quality of life (Stones et al., 2000). Clinical effects are often seen within 1 week of injection, and benefits typically last from 3 to 6 months. Multiple dosing is utilised to extend the treatment effect and has been demonstrated to be beneficial in neuromuscular disorders, muscle spasticity and detrusor overactivity (Bakheit et al., 2001).
There are limited data on the long-term effects of recurrent dosing with botulinum toxin type A, however there is concern with regards to potential toxicity, antibody formation and secondary failure of botulinum toxin type A treatment (Lange et al., 2009). Given the proximity of pelvic sphincters to the injection site for gynaecological applications of botulinum toxin type A, the effects of long-term muscle wasting and remodelling on both target- and non-target muscles is critical in the evaluation of this treatment (Fortuna et al., 2011).
Our unit has previously conducted a series of studies demonstrating that the use of botulinum toxin type A improved pelvic pain and vaginal pressures in women with pelvic floor muscle hypertonicity (Abbott et al., 2006; Jarvis et al., 2004). This study aims to report the longitudinal outcomes for repeat injections of botulinum toxin type A into the pelvic floor muscles of women with objective pelvic floor muscle overactivity, as well as the interval to re-injection, pain outcomes and vaginal pressures with repeated injections.
Section snippets
Materials and methods
This is a prospective cohort study carried out at the Department of Endo-Gynaecology, Royal Hospital for Women, Sydney, Australia. This study received approval from the institutional scientific and ethics committees (HREC ref 03/102).
Demographics
Thirty-seven women, aged 21–52 years were recruited to the study. The demography and history of the participants requiring single injection and multiple injections were similar and are outlined in Table 1. There were 66 distinct injections of botulinum toxin type A administered to 37 women over the study period. Twenty-six women (70%) had one injection of botulinum toxin type A and 11 (30%) had two or more injections. The median number of repeat injections was 3 (range 2–6). Median time to
Single vs. repeat injections
Following failure of conservative treatment for chronic pain, botulinum toxin type A has been successfully used (Abbott, 2009; Abbott et al., 2006; Jarvis et al., 2004; Thomson et al., 2005), however there are few long-term clinical results available. Repeat injections are described for muscle overactivity including stroke patients and cerebral palsy (Bjornson et al., 2007; Bakheit et al., 2001), cervical dystonia causing migraine (Truong et al., 2008; Blumenfeld et al., 2003; Binder et al.,
Conclusion
In conclusion, botulinum toxin type A is an effective treatment for pelvic floor muscle overactivity, in both single and multiple dosing regimes. Long-term side effects seen in other non-gynaecological studies of repeat botulinum toxin type A injections seem to be associated with higher dosing and shorter treatment intervals making toxicity and the development of antibodies unlikely for current gynaecological indications. Local muscle effects of remodelling and atrophy could be of some concern
References (20)
Gynecological indications for the use of botulinum toxin in women with chronic pelvic pain
Toxicon
(2009)- et al.
Pelvic pain scores in women without pelvic pathology
Journal of the American Association of Gynecologic Laparoscopists
(2002) - et al.
Botulinum toxin type A (BOTOX) for treatment of migraine
Disease-A-Month
(2002) - et al.
Changes in contractile properties of muscles receiving repeat injections of botulinum toxin (Botox)
Journal of Biomechanics
(2011) - et al.
Efficacy of botulinum toxin-A for treating idiopathic detrusor overactivity: results from a single center, randomized, double-blind, placebo controlled trial
Journal of Urology
(2007) - et al.
Botulinum toxin therapy for neurogenic detrusor overactivity
Urologic Clinics of North America
(2010) - et al.
Psychosocial and economic impact of chronic pelvic pain
Best Practice and Research Clinical Obstetrics and Gynaecology
(2000) - et al.
Efficacy and safety of purified botulinum toxin type A (Dysport) for the treatment of benign essential blepharospasm: a randomized, placebo-controlled, phase II trial
Parkinsonism & Related Disorders
(2008) - et al.
Botulinum toxin type A for chronic pain and pelvic floor spasm in women: a randomized controlled trial
Obstetrics & Gynecology
(2006) - et al.
A randomized, double-blind, placebo-controlled study of the efficacy and safety of botulinum toxin type A in upper limb spasticity in patients with stroke
European Journal of Neurology
(2001)
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2023, European Journal of Obstetrics and Gynecology and Reproductive BiologyEvidence for increased tone or overactivity of pelvic floor muscles in pelvic health conditions: a systematic review
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The Benefits and Harms of Botulinum Toxin-A in the Treatment of Chronic Pelvic Pain Syndromes: A Systematic Review by the European Association of Urology Chronic Pelvic Pain Panel
2022, European Urology FocusCitation Excerpt :The characteristics of the included studies and their patient demographics are summarised in Table 1. Seven studies (five RCTs [14–18] and two NRSs [19,20]) assessed the use of BTX-A in bladder pain syndrome (BPS), four studies (three RCTs [21–23] and one NRS [24]) in gynaecological pelvic pain (GPP), three studies (two RCTs [25,26] and one NRS [27]) in prostate pain syndrome (PPS), one study (NRS [28]) in patients with chronic anal fissures, and one study (RCT [29]) in patients with myofascial pelvic pain (MPP). Insufficient data were provided about funding sources and conflicts of interest.
Botulinum toxin to treat pelvic pain
2018, Toxicon