I was in central Glasgow last week. On my rainy travails down Buchanan Street, I came across a tent pitched just beside the statue of Donald Dewar. Beside that was a mat on the ground with pictures of hot coals on it, that invited people to try and experience the trial of “chronic pain”. The smiling ladies giving out leaflets were wearing t-shirts saying “Still in pain? Take Control”. The leaflets asked “Are you still suffering?” and offered “Help on discussing neuropathic pain with your doctor”.
Here are some quotes from the leaflet
“When will I feel better? … The ‘right treatment’ for you may mean speaking with your doctor to identify other treatments that may provide greater, long-term, pain relief or fewer side effects. Your doctor may have to prescribe more than one treatment before they find the one that is right for you and this may take time.”
“Keep talking to your doctor. If you are still in pain or have experienced side effects that make you want to stop your treatment, you should go and see your doctor as they may choose to alter the dose or prescribe another treatment.”
“If you are still experiencing pain or the side effects of your current medication are causing you problems, you should visit the doctor as there may be other treatment options available that better suit you.”
“Discuss your pain regularly with your doctor, especially if it is not improving or you have concerns.”
The conversation I had went like this:
“Could I have a leaflet please?”
“Certainly. Have you heard much about chronic pain?”
“That’s great, most people haven’t heard of it.”
“So what are Pzifer promoting?”
“Nothing, this is just an awareness campaign.”
“Yeah, but Pfizer must be promoting something. What is it?”
“It’s a patient awareness campaign.”
“Oh I know. It’s pregabalin that Pfizer make, isn’t it?”
Pregabalin is sold under the trade name Lyrica, which is made by Pfizer. Pfizer also make Gabapentin, under the trade name Neurotonin. Gabapentin is now off-patent, and is available as a generic, cheaper, unbranded drug, for use in chronic pain. I do not like conflict. Doctors should naturally be on the same side as the patient. I want my patients to have the best possible care, and best possible care means fair information, and realistic expectations.
So what is fair information about pregabalin?
The Drugs and Therapeutics Bulletin, which is an independent mini-journal, wrote about pregabalin in October 2006. They noted that it was licensed for treating neuropathic pain. Compared to gabapentin, its older but similar drug cousin, it seemed, in both in-vitro and animal studies, to bind well to pain relief receptors. However, they noted that it was “unclear whether this translates into a clinical advantage”. It is also very useful to note that the timing of the “launch of pregabalin co-incided with gabapentin’s imminent availability as a generic” – which would have been cheaper for the NHS to prescribe.
So is pregabalin better than gabapentin? Looking at the evidence on PubMed reveals very few head-to-head trials; instead, most compare pregabalin with placebo. The same paper in the Drugs and Therapeutics Bulletin noted that largest study comparing pregabalin to both gabapentin and amitriptyline (an older drug which works in small doses as a painkiller for nerve pain, and in larger doses as an antidepressant) was done in patients with nerve pain due to diabetes. The reduction in pain score was not significant in the case of pregabalin, but were significant for amitriptyline compared to placebo.
Additionally, the side effects of pregabalin compared to gabapentin have also been found to be similar. The Bulletin concludes that “neuropathic pain is an area where there are few licensed alternatives” but also that “there is no evidence to use pregabalin instead of the now much cheaper, similar, generic, gabapentin”. A further review examining uses of pregabalin in 2008 in the European Journal of Pain concluded that “there are a lack of studies comparing gabapentin and pregabalin in treating neuropathic pain in spinal cord injury”. The Scottish Medicines Consortium (the northern NICE equivalent) said last year that “pregabalin (Lyrica), for the treatment of central neuropathic pain in adults, should not be recommended for use within NHS Scotland” because “clinical and cost effectiveness have not been demonstrated”. In other words, there is no evidence that pregabalin is going to be a better drug than the cheaper generic gabapentin along with the older drugs that are used for treating chronic pain.
I can’t imagine, though, that is the kind of conclusion that Pfizer were hoping for.