The evidence for noncosmetic uses of botulinum toxin
Botulinum toxin has been studied for a variety of uses beyond the cosmetic. Here’s what you need to know about which uses are worth considering for your patient.
PRACTICE RECOMMENDATIONS
› Do not use botulinum toxin for episodic migraine, tension headache, or cluster headaches. B
› Consider off-label use of botulinum toxin for select patients with occipital and trigeminal neuralgia, gastroparesis, vaginismus, benign prostatic hypertrophy, neonatal brachial plexus palsy, post-stroke spasticity, and hemifacial spasm. B
› Consider the use of botulinum toxin as an adjunct in chronic low back pain management. B
Strength of recommendation (SOR)
A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series
Dysfunctional voiding, urethral sphincter overactivity, and Fowler syndrome involve urethral sphincter spasticity with difficulty passing urine and possibly retention. Urethral sphincter injections of 100 U BoNT-A improved flow rates and decreased residual volume. A randomized, double-blinded, placebo-controlled study showed a significantly improved International Prostate Symptom Score (IPSS), quality of life index, maximum flow rate, voided volume, and decreased detrusor voiding pressure at 1 month.29
Benign prostatic hypertrophy (BPH) is a very common condition leading to outlet obstruction. The mainstays of treatment are 5-α-reductase inhibitors, α-adrenergic blockers, and surgical removal.
Gynecologic disorders
Vaginismus is the involuntary, recurrent, or persistent contraction of the perineal muscles surrounding the outer third of the vagina; it is classified by 4 progressively more severe degrees of intensity. Levator ani, bulbospongiosus, bulbocavernosus, pubococcygeus, and/or puborectalis muscle BoNT-A injections have shown benefits in decreasing resistance to vaginal exams (95.8%) and the ability to achieve satisfactory sexual intercourse after first injection (75%-100%). Effects were transient for up to 15.4% of patients requiring repeat injections.28
Vulvodynia is vulvar pain and orgasmic difficulties and has been treated with bulbospongiosus muscle BoNT-A injections in retrospective studies. A single randomized, double-blinded, placebo-controlled study showed significantly improved pain scores after 1 to 2 injection series.28
Chronic pelvic pain is a syndrome of somatic functional or regional pain, which can be caused by the spasm of the pelvic musculature with or without trigger points. Patients with pain refractory to treatment have been treated with levator ani injections. A retrospective cohort study found 79.3% of patients experienced pain relief and 20.7% reported improved symptoms. In a double-blind, randomized, placebo-controlled trial, pelvic floor muscles were injected with 80 U BoNT or saline, and symptoms were evaluated along with vaginal manometry. BoNT was associated with a reduction in some pain but not as much as placebo, while vaginal pressures decreased more with BoNT than with placebo.28
Blake Busey, DO, FAAFP, Texas Tech University of Health Sciences El Paso–Transmountain, 2000B Transmountain Road, Suite B400, El Paso, TX 79911; blake.busey@ttuhsc.edu
