To treat neuropathic pain
, drug treatments are oftentimes the best strategy, particularly when coupled with other available therapies for pain management. The current drug treatments for neuropathic pain
are focused on dampening the neuronal input to patient consciousness. This is done by suppressing axonal function. It is also achieved by interfering with neurotransmission.
The drugs used to treat neuropathic pain can be divided into two types:
- Medications that treat other conditions (but also useful in neuropathic pain)
Often working out a better management system for the causative disease or disorder can, in turn, reduce its neuropathic pain. Efficient management of the condition also has the potential to prevent further nerve damage.
Unfortunately, neuropathic pain often responds poorly to over the counter pain treatments. For some patients, their pain can worsen and turn into a serious disability. Combining therapies have been found to offer the best result in providing relief from neuropathic pain.
Medications for the treatment of Neuropathic Pain
To relieve the discomfort from neuropathic pain, some patients opt to use non-steroidal anti-inflammatory drugs. This may work for a select few, but many patients find the relief to be mild and of little consequence. Examples of this kind of medication:
Most patients experiencing neuropathic pain require a medication that packs more punch. To gain this kind of pain relief, many will consume medications containing morphine.
Anticonvulsant medications (neuroleptic drugs)
- valproic acid
Antidepressant drugs called tricyclic antidepressants (TCA’s)
Local anaesthetics (intravenous application)
Other treatments available to relieve neuropathic pain:
- Physical therapy
- Working with a counsellor
- Relaxation therapy
- Massage therapy
- Implantable Device – electrical stimulation of nerves
Medical Cannabis Treatment for Neuropathic Pain
Endocannabinoid System and Pain
Cannabinoid receptors, specifically CB1 are well distributed throughout the endogenous pain modulation pathway. Key areas in pain transmission include the periaqueductal grey matter, rostral ventromedial medulla and the primary afferent neurones. Studies have shown that up-regulation of the endocannabinoid system is known to produce an analgesic effect.
Primary Afferent Neurons
Studies in mice in which CB1 receptors were removed from primary afferent nociceptive sensors showed an increased sensitivity to noxious stimuli. From this, the researchers proposed CB1 receptors are involved in primary pain transmission from the periphery to the spine. Furthermore, these rats were found to be hypersensitive to noxious stimuli, which supports the hypothesis. Transient potential vanilloid receptors are also found on the primary afferent neurones and suggested to work synergistically with cannabinoid receptors to reduce pain transmission when activated by cannabinoids.
Periaqueductal Gray Matter
The PAG is considered the relay centre for pain in the brain. PAG electrical stimulation is well known to produce analgesic effects in rats. CB1 receptors are densely concentrated through the PAG. Studies have shown that injection of cannabinoids into the PAG produce a similar analgesic effect that was reversed by a CB1 antagonist. Analgesic effect is generated in PAG via transmission of pain signals to the descending nociceptive pathway. The degree to which pain is modulated in this area of the brain is determined by GABA and glutamate excitation. Glutamate stimulation is known to have an analgesic effect. Conversely, GABA excitation is inhibitory to the descending antinociceptive pathway. Traditional opioid analgesics produce a slightly stronger antinociceptive effect than cannabinoids. Opioid treatment results in a decrease of spinal opioid receptors, whereas CB1 receptors are unregulated in neuropathic pain.
Rostral Ventromedial Medulla
RVM contains two cell types which are know to influence the descending antinociceptive pathway. ON cells are associated with increased pain signalling. OFF cells are associated with the analgesic effect. Cannabinoid receptor agonists have been shown to reduce the ON cell burst and decrease the OFF cell pause.
Statistics for Neuropathic Pain in Australia
29 percent of Australians experience chronic pain., which if you think about it, this means around three out of every ten people are suffering in some way, shape or form. (Stollznow Research for Pfizer Australia, 2010).