Anti-epileptic medication is used to treat neuropathic pain, sometimes in combination with other medication and in concert with physical and cognitive therapies. This class of medication was previously referred to as anticonvulsive medication. Neuropathic pain arises from injured nerves caused by disease or trauma. This pain is different to nociceptive pain eg musculoskeletal pain and requires different medication to treat it. Simple medication such as paracetamol or ibuprofen may not be effective for neuropathic pain, while medicines that are used to treat epilepsy can be very effective in some people with neuropathic pain.
Fibromyalgia is a widespread pain condition and evidence is lacking as to whether it has a neuropathic pain component, but fibromyalgia can also respond to anti-epileptic medication in some people.
A systematic review of anti-epileptics in chronic pain identified various anti-epileptics such as carbamazepine, gaberpentin and pregabalin being effective for chronic pain conditions, particularly neuropathic pain and headaches.
Carbmazepine (Tegretol) is used to control sudden attacks of facial pain (trigeminal neuralgia) by regulating nerve function in the body. The Cause of trigeminal neuralgia is idiopathic, that is , in most cases, it is unknown. However, other causes may be a compressed nerve, aneurysm or tumour. The pain of trigeminal neuralgia is severe and may be an isolated episode or recurrent eg every few hours, minutes or seconds. Sometimes there are months or years between attacks although in some patients it can become chronic, interfering with daily life. Though it can affect people of any age, trigeminal neuralgia tends to affect people older than 60 years of age.
Gaberpentin (Neurontin, Gantin, Gabahexal) may be used to treat shingles pain and other neuropathic pain conditions such as diabetic neuropathy, peripheral neuropathy, trigeminal neuralgia and restless legs syndrome. In animal studies, gabapentin could prevent allodynia (pain in response to a normally non painful stimulus) and hyperalgesia (exaggerated response to a painful stimulus).
Pregabalin (Lyrica) is effective in some people with neuropathic pain conditions such as post herpetic neuralgia and cancer related neuropathic pain and can also improve sleep. There is evidence of effectiveness in central neuropathic pain eg pain after stroke as well as in fibromyalgia. The drugs can work very well in some people with these conditions. Pregabalin has been associated with less side-effects and it may also mean that less analgesics eg opioids can be used.
If Epilim or Tegretol are prescribed, then you will have tests performed for the first couple of months to check your blood count and liver function, to make sure you're not developing any unwanted, but uncommon side effects to this medication. Gaberpentin and pregabalin do not require this monitoring and are frequently prescribed at public hospitals pain management clinics.
Somnolence (feeling sleepy) and dizziness are the most common minor adverse events with anti-epileptics.
Avoid eating grapefruit or drinking grapefruit juice while using carbamazepine unless your doctor or pharmacist says you may do so safely. Grapefruit can increase the chance of side effects with this medicine. Ask your doctor or pharmacist for more information.
Take anti-epileptic medication regularly to get the most benefit from it. To help you remember, take it at the same time each day. It is important to continue taking this medication even if you feel well.
Do not stop taking the anti-epileptic medication without consulting your doctor. Some conditions may become worse when the drug is suddenly stopped. Your dose of the medication may need to be gradually decreased.