When people experience neuropathic pain it may be due to damage to the nerves that control pain and sensation. Unfortunately our bodies are not very good at repairing damaged nerves. In some people, their bodies create inflammation and different chemicals to try and repair the nerve. These chemicals can lead to ‘turning up’ the volume on these nerves turning your pain from a 2 to a 10.
If you are someone whose pain is worsened by these chemicals, then we can try to dampen the signal with medications. For some people, we can give medications by mouth to help. These medications can work very well for some people, but unfortunately some people may experience side effects such as sedation or nausea which prevents them taking the medication. They may also have other reasons why they cannot have oral medication such as renal or liver problems.
We can attempt to use these same medications in a cream form which can be very effective for some people. As everyones pain is different, skin is different, and chemicals are different, performing standardised research studies has been difficult and this is an evolving area of research. Some studies have shown benefit while other studies have not. It is clear that using these creams for everyone, for every pain condition, is unlikely to be of benefit.
Will this definitely work for me? Not necessarily. Absorption of medicine through the skin is variable so it can be hard to predict. But for some people it can be effective. As pain specialists our role is to help guide whether we think this sort of medication may be useful for one person, but less helpful for another. Your doctor will help guide whether you are more likely to gain benefit than someone else.
Are there down sides with trying it? Possibly. Creams cost between $40-$100 and require you to put them on two to three times a day. If they do not work for you, then unfortunately it has cost you a small amount of money. Many people decide that the possible benefit is worth trying the medication for. You also need to do this for at least 3-4 weeks to build up enough medication in the area to see if it works for you. Rarely you can have a skin reaction if you have allergic tendencies. This settles usually with ceasing the cream.
Are there different formulations? Yes. We have some with amitriptyline, clonidine, lignocaine, NSAIDs, ketamine and gabapentin, capsaicin and baclofen. Your doctor can advise which formulation is most likely to help you.