Topical Tricyclic Antidepressants

Few classes of drugs are more extensively used in the management of chronic pain conditions than the tricyclic antidepressants (TCAs). Substantial and convincing evidence supports their use in a variety of pain conditions including neuropathic pain and the pain associated with fibromyalgia. Their use is so common that it is now normal for them to be initiated by General Practitioners. The pain relief that may be apparent is independent of their antidepressant effects but any mood improvement...

Clinical use of 5HT3 antagonists

While 5HT3 antagonists may ultimately find a place in the management of metastatic bone pain and in reducing opioid tolerance at present this use would be speculative. Their use in the other circumstances mentioned above is more firmly based. From a practical perspective the following guidelines for use is suggested and are based on my own personal experience of use of these drugs. Use of a 5HT3 antagonist in the treatment of neuropathic pain may be reserved for management of a flare-up in view...

Tropisetron

Tropisetron belongs to the 5HT3 antagonist group of drugs. This group has been marketed for its antiemetic effect which is most well established in the fields of postoperative nausea and vomiting and in chemotherapy-induced nausea. More recently it has been shown that 5HT3 antagonists, when given systemically, can also have an analgesic effect on the pain associated with fibromyalgia and irritable bowel syndrome and even in patients with neuropathic pain. This effect is produced by their...

Parenteral Antiepileptics

Those involved in neurology and neurosurgical practice will be familiar with the use of intramuscular and intravenous (IV) anti-epileptic drugs (AEDs) for the treatment and prevention of epileptic seizures. Their use by those in purely pain practice is much less common. Historically the first AED to be used in the treatment of pain was when phenytoin was used in the treatment of facial neuralgia in the early 1940s. Since that time oral phenytoin has been shown to be effective for the treatment...

Human studies

While extensive animal evidence points to an opioid enhancing effect of CCK antagonists with an additional effect on antinociceptive tolerance, the human literature is slight and somewhat contradictory. The suggested use of CCK antagonists, and in particular proglumide, is based on extensive clinical use, rather than on the weight of human scientific evidence. A number of human studies have examined the effect of the mixed CCK A and B antagonist proglumide. They have shown that it enhances the...

Bibliography

Bernstein ZP, Yucht S, Battista E et al. Proglumide as a morphine adjunct in cancer pain management. J Pain Symptom Manage 1998 15 314-20. Bodnar RJ, Paul D, Pasternak GW. Proglumide selectively potentiates supraspinal mu opioid analgesia in mice. Neuropharmacology 1990 29 507-10. Bras JM, Laporte A-M, Benoliel JJ et al. Effects of peripheral axotomy on cholecystokinin neurotransmission in the rat spinal cord. J Neurochemistry 1999 72 858-67. Coudore-Civiale MA, Courteix C, Boucher M et al....

Side effects of antiepileptic drugs

When we consider drug side effects, much of the available evidence comes from drug studies which are almost universally of short duration. Therefore side effects recorded are the acute side effects and not those associated with long-term therapy. Since neuropathic pain, the primary indication for AED use is often long term if not lifelong, consideration should be given not only to the acute side effects associated with the use of a particular drug, but also to the long-term consequences of its...

Conditions which may benefit from topical TCA

The use of a topical TCA is only appropriate when the area over which pain is felt is relatively limited. If applied over too wide an area, systemic uptake will occur with an increased likelihood of systemic side effects. Uses are not limited just to neuropathic pain conditions The use of a topical TCA for urinary frequency and dysuria requires some explanation. In those who have to intermittently self-catheterize their bladders, dysuria and frequency can complicate repeated catheterization. If...

Treatment

All treatment comes with the proviso that active mobilization is an essential facet of treatment. In some individuals a single cause of back pain can be identified, while in others several structures generate pain and specific treatment of each will be required to increase the chance of therapeutic success. In still further cases, when an individual type of pain originating from a single structure is identified and treated, further sources of pain become obvious either because they were masked...

Neuropathic pain

Pain arising from injury or irritation of neural tissue may result in neuropathic pain. This pain has characteristic features which distinguish it from pain arising from noxious stimulation of other non-neural structures. Accepted treatment for neuropathic pain involves the use of three distinct classes of medication 2 Antidepressants - Tricyclic antidepressants TCAs and serotonin norepinephrine reuptake inhibitors SNRIs While other types of medication are used, these three groups form the...

Gabapentinoids

The gabapentinoids, gabapentin, and pregabalin exert their analgesic effect by interaction with the a-52 sub-unit of the calcium channel and are known to have an anti-allodynic and anti-hyperalgesic effect when used in the treatment of neuropathic pain. It is now known that these drugs can also reduce postoperative pain, reduce postoperative opioid requirement, and consequently reduce opioid-related side effects. Interestingly, the current evidence would suggest that the opioid-sparing effect...

Topical options Glyceryl trinitrate

We have seen earlier that the topical application of nitrates in the form of glyceryl trinitrate GTN can have both an analgesic and anti-inflammatory Corticosteroid injection repeated X 1, if necessary if no relief and in case of calcific tendonitis Glyceryl trinitrate patch, 5 mg per 24 h, 1 4 to 1 2 patch topically daily. A 0.025 capsaicin topically four times daily for at least 1 month. A 5 doxepin cream topically four times daily for at least 1 month. For example, triamcinolone acetonide...