Introduction to treatments for shingles pain (post-herpetic neuralgia)
based on the 4-page Guidelines for doctors by
Dr Mick Serpell, MA, MD, PhD, FRCPed, FRCPath, consultant anaesthiologist (pain specialist)
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EXPLANATION
Shingles pain may get better by itself, but in some cases it can continue for years. As we get older, it becomes more likely that this pain or discomfort may be long lasting, particularly in patients who are over 60. It is then called postherpetic neuralgia (PHN) For some, this may continue indefinitely. If it prevents you from living a normal life, you should arrange to start treatment as soon as possible.
PHN is the result of nerves being irritated or damaged by the chickenpox virus when it causes a shingles outbreak. Not only does the function of the damaged nerve become abnormal, as is shown by the loss of ordinary sensation, changes seem also to affect the spinal cord or central nervous system as well. We know this because, unfortunately, cutting the affected nerve is unlikely to cure the pain of PHN - the severed nerve ends still transmit pain signals to the brain. (This is similar to ghost pain felt by people who have had a limb amputated.) Doctors Kanazi, Johnson and Dworkin report that “the use of sympathetic nerve blocks [injections] do not appear to provide prolonged relief in patients with longstanding PHN.”
TREATMENTS
Ordinary painkillers such as co-codamol or co-proxamol have little effect on PHN. You may want to ask the doctor for stronger prescription drugs that have been shown to help – these are codeine, tramadol and other ‘opiods’. These are short-term treatments: they work immediately but then they wear off in a few hours.
The best treatments set up a long-term pain-block. A common treatment is amitriptyline or another similar antidepressant drug. These drugs are now mainly used as pain treatments. Other drugs like gabapentin and pregabalin are also being used. People who are already taking several different tablets or who are bothered be side effects, may prefer to try a chilli pepper cream or an anaesthetic patch. These treatments are not traditional painkillers so they do not give immediate relief and may take several weeks to become fully effective.
PILLS:
1. Antidepressant drugs such as amitriptyline or nortriptyline are started at a low dose, usually 10 mg, and gradually increased to 50 mg or even 75mg. If you get a ‘dry mouth’ sensation, try sipping water or fruit juice, or sucking a sweet. (NB you can buy sugar-free or diabetic sweets if you are controlling your weight.) Side effects usually wear off as you get used to the treatment. As Mrs S. reported: ‘... it did ease the dreadful pain. I had one or two side effects when taking the pills but I could cope with them … to ease the pain was the main thing and amitriptyline did that.
2. Anti-epileptic drugs such as gabapentin and pregabalin are now widely used for treating neuropathic pain such as PHN. Usually gabapentin is started off with a low dose and increased to 400mg, 3 times a day; dosage can be up to 800 mg, 3 times a day. The dosage for pregabalin is between 75 and 300 mg twice a day. These drugs do not interfere with other medication and should have few side effects.
CREAM
3. Axsain cream (capsaicin – or chilli pepper cream) has been proven to be effective at stopping the pain. You massage it onto (or near to) the painful place, that is, in the same dermatome region. This could be on the forehead or cheek if the pain is near your eye or under your hair. Use a small (pea sized) amount 3 or 4 times a day for about 3 weeks. Axsain stops the pain for seven out of ten people.
Note that the cream can sting so some people use an anaesthetic cream first to numb the area – about 15 minutes before applying Axsain. Use Instillagel 2% gel or lidocaine 5% ointment – they are not expensive and no prescription is needed; or try Xylocaine 10% (also no prescription). Your chemist should be able to get it for you. These items can also be prescribed by your doctor.
PATCH
4. Anaesthetic plaster, “Versatis” is a new treatment: a patch that you apply to the affected area for 12 hours on, 12 hours off every day. If you wish you can try wearing it up to 36 hours on and then 12 hours off – it will still be effective.
5. Chilli pepper patch. Qutenza (capsaicin) 8% is a skin patch containing a synthetic equivalent of the naturally occurring capsaicin compound found in chilli peppers. A doctor or nurse will numb the area using an anaesthetic cream and the patch is then applied for one hour. This process should reduce or eliminate the pain for three months, after which the treatment can be repeated if required. This is a new treatment, so healthcare workers in specialist centres around the country are being trained in the use of this patch.
RARE COMPLICATIONS
Two groups focus on conditions that sometimes occur: Trigeminal Neuralgia, PO Box 413, Bromley, BR2 9XS (www.tna.org.uk) 020 84462 9122; Bell’s Palsy (www.bellspalsy.org.uk) 0870 44 45 460.
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"NEWS!!! FLASH NEWS!!! NEWS!!!
A vaccine will soon be available to prevent shingles. The Department of Health has said that when agreement is reached with the supplier, it will be made available to 70-79 year olds. People outside that age-group may be able to ask their GPs for it, or pay for it privately.
To encourage action on this: PLEASE write to your MP and ask him/her to write to the Health Minister to find out when this shingles vaccine will be available to others. If you can add a bit to the letter about why you think this is a good idea, then so much the better.
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This page was last updated on 9-2-2011. It is is due for review no later than 9-2-2013.
