Botulinum toxin for severe anorectal pain

Rectal enema of bupivacaine in cancer patients with tenesmus pain - case series

Introduction: Rectal tenesmus pain in cancer patients most frequently appears in patients with colon cancer, and as a consequence of radiotherapy of the hypogastrium region. Treatment with opioids and adjuvant analgesics is often ineffective. Patients and methods: Here, we report on two female patients diagnosed with colon and ovary cancer, respectively, who had very severe tenesmus pain (numerical rating scale 8-10) despite using high doses of opioids, including methadone with corticosteroids, anticonvulsants, antidepressants and ketamine. Results: In both patients, bupivacaine was administered via a rectal enema. In the first patient, bupivacaine was administered at a dose of 100 mg 0.1% (100 mL), and subsequently 100 mg 0.2% (50 mL), leading to effective analgesia for 8 and 12 hrs, respectively. In the second patient, 100 mg 0.1% (100 mL) was initially administered, followed by 100 mg 0.2% (50 mL), leading to effective analgesia for 12 and 17 hrs, respectively, with only dull abdominal pain reported that was relieved by 100 mg IV ketoprofen and complete disappearance of tenesmus pain. Rectal bupivacaine administration did not cause neurologic adverse effects, heart function disturbances or decreased blood pressure. A volume of 50 mL was enough to cover a painful area in the colon. Initial bupivacaine concentrations in the blood serum did not exceed 50 ng/mL and eventually dropped to 20 ng/mL and below. Conclusions: Administration of 100 mg bupivacaine as a rectal enema is safe and provides effective analgesia, and this procedure may be conducted in hospital departments and out-patient clinics. Furthermore, this procedure in the case of pain recurrence, can be repeated, and by providing effective pain relief often allows time for the patient to be transferred to a specialized pain center.

Interventional Pain Management in Multidisciplinary Chronic Pain Clinics: A Prospective Multicenter Cohort Study with One-Year Follow-Up

Background

Interventional Pain Management (IPM) is performed in multidisciplinary chronic pain clinics (MCPC), including a range of invasive techniques to diagnose and treat chronic pain (CP) conditions. Current patterns of use of those techniques in MCPC have not yet been reported.

Objective

We aimed to describe quantitatively and qualitatively the use of IPM and other therapeutic procedures performed on-site at four Portuguese MCPC.

Methods

A prospective cohort study with one-year follow-up was performed in adult patients. A structured case report form was systematically completed at baseline and six and 12 months.

Results

Among 808 patients referred to the MCPC, 17.2% had been prescribed IPM. Patients with IPM were on average younger and had longer CP duration and lower levels of maximum pain and pain interference/disability. The three main diagnoses were low back pain (n = 28), postoperative CP, and knee pain (n = 16 each). From 195 IPM prescribed, nerve blocks (n = 108), radiofrequency (n = 31), and viscosupplementation (n = 22) were the most prevalent. Some IPM techniques were only available in few MCPC. One MCPC did not provide IPM.

Conclusions

IPM are seldom prescribed in Portuguese MCPC. Further studies on IPM safety and effectiveness are necessary for clear understanding the role of these techniques in CP management.

Botulinum toxins: mechanisms of action, antinociception and clinical applications

Botulinum toxin (BoNT) is a potent neurotoxin that is produced by the gram-positive, spore-forming, anaerobic bacterium, Clostridum botulinum. There are 7 known immunologically distinct serotypes of BoNT: types A, B, C1, D, E, F, and G. Clostridum neurotoxins are produced as a single inactive polypeptide chain of 150kDa, which is cleaved by tissue proteinases into an active di-chain molecule: a heavy chain (H) of ∼100 kDa and a light chain (L) of ∼50 kDa held together by a single disulfide bond. Each serotype demonstrates its own varied mechanisms of action and duration of effect. The heavy chain of each BoNT serotype binds to its specific neuronal ecto-acceptor, whereby, membrane translocation and endocytosis by intracellular synaptic vesicles occurs. The light chain acts to cleave SNAP-25, which inhibits synaptic exocytosis, and therefore, disables neural transmission. The action of BoNT to block the release of acetylcholine botulinum toxin at the neuromuscular junction is best understood, however, most experts acknowledge that this effect alone appears inadequate to explain the entirety of the neurotoxin's apparent analgesic activity. Consequently, scientific and clinical evidence has emerged that suggests multiple antinociceptive mechanisms for botulinum toxins in a variety of painful disorders, including: chronic musculoskeletal, neurological, pelvic, perineal, osteoarticular, and some headache conditions.

[Long-term treatment of phantom- and stump pain with Botulinum toxin type A over 12 months. A first clinical observation]

Recently we were able to describe the successful treatment of phantom pain and stump pain with botulinum toxin A in a first pilot study. This case report over a 1-year period now demonstrates that long-term treatment for this indication is possible. We injected 4 x 25 IU of botulinum toxin A (Botox) into trigger points of the stump muscles of a lower limb amputee who suffered from severe phantom and stump pain. With four injections performed every 3 months, the patient became almost completely pain-free, and his intrathecal morphine therapy could be reduced to 40% of the initial dose. Intrathecal clonidine was eliminated completely, as were the oral analgesics. A surgical treatment suggested for the stump pain was no longer necessary, and we suppose that botulinum toxin can also improve the tolerance of artificial limbs in cases of stump pain.

Noncosmetic uses of botulinum toxin

In conclusion, botulinum toxin usage over the past 2 to 3 decades has expanded exponentially. Almost every discipline in medicine has found some therapeutic use for this toxin. Botulinum toxin has been shown to be safe, effective, and relatively easy to administer with proper training.

Treatment with botulinum neurotoxin of gastrointestinal smooth muscles and sphincters spasms

Local injections of botulinum neurotoxin are now considered an efficacious treatment for neurological and non-neurological conditions. One of the most recent achievements in the field is the observation that botulinum neurotoxin provides benefit in diseases of the gastrointestinal tract. Botulinum neurotoxin inhibits contraction of gastrointestinal smooth muscles and sphincters; it has also been shown that the neurotoxin blocks cholinergic nerve endings in the autonomic nervous system, but it does not block nonadrenergic responses mediated by nitric oxide. This aspect has further promoted the interest to use botulinum neurotoxin as a treatment for overactive smooth muscles, such as the anal sphincters to treat anal fissure and outlet-type constipation, or the lower esophageal sphincter to treat esophageal achalasia. Knowledge of the anatomical and functional organization of innervation of the gastrointestinal tract is a prerequisite to understanding many features of botulinum neurotoxin action on the gut and the effects of injections placed into specific sphincters. This review presents current data on the use of botulinum neurotoxin to treat diseases of the gastrointestinal tract and summarizes recent knowledge on the pathogenesis of disorders of the gut due to a dysfunction of the enteric nervous system.

Noncosmetic uses of botulinum toxin

Since the introduction of botulinum toxin (BTX) as a therapeutic tool in the 1970s, the number of uses for this substance has increased exponentially. BTX's mechanism of action involves degrading the SNARE proteins blockading the release of acetylcholine into the neuromuscular junction. In many body systems, decrease of contractility, strength, and tension of certain muscle groups result in improved clinical outcomes. Applications now include cosmetic, gastroenterologic, otolaryngologic, genitourinary, neurologic, and dermatologic uses. In fact, BTX can be considered as a potential treatment in any situation involving inappropriate or exaggerated muscle contraction. Currently, the FDA has approved BTX-A (Botox) for treating glabellar lines, blepharospasm, strabismus, hemifacial spasm, cervical dystonia, and spasticity. With the addition of cosmetic applications to the FDA's approval list, the use of BTX has increased dramatically.