Gabapentin has been described as a ‘wonder drug’ for its ability to treat unpleasant nerve pain (neuropathic pain). In the UK, pregabalin and gabapentin prescribing has increased by 350% and 150% respectively in the last 5 years. Few of us realise that it was however first invented to treat epilepsy. Gabapentin belongs to a group of medicines called anticonvulsants which are also used to treat epilepsy but don’t be alarmed by this.
Gabapentin was invented in 1974 by the pharmaceutical drug company Parke-Davis (now a division of Pfizer) and it was developed initially specifically as an anti-seizure drug. The reasons for its development was that researchers wanted to find something that would help influence the presence of a neurotransmitter called GABA (gamma-aminobutyric acid) in our brain. It had long been suspected that epileptic patients had a deficiency of GABA. The main issue at that point in time was that GABA could not cross the blood-brain barrier so it had to be combined into another chemical structure. This was how gabapentin was born. Significantly gabapentin was close to ideal as it remained unmetabolised as it passed through our body meaning that it had fewer interactions and therefore less side affects.
Following further research and clinical trials it was approved for use in America in 1993 under the brand name Neurotonin and by 2001 sales had reached $1.2 billion. By the mid 1990’s it was also becoming obvious that neurotonin also had an a good effect on nerve/neuropathic pain. This is type of specific pain is hard to treat. Most analgesics based on opioids (such as codeine) and others such as paracetomol are not effective.
As neurotonin had a good safety profile and with few side effects, it posed minimum risk to patients participating in clinical trials undertaken to assess it’s efficacy alleviating neuropathic pain. Subsequent successful trials were well documented in pain management journals and conferences at the time. By 2002 the treatment of neuropathic (or nerve) pain with neurotonin had been officially approved both in the United States and the UK and by the following year 83% of Neurontin prescriptions were for non-epilepsy conditions. In 2004, Pfizer released pregabalin, a version of gabapentin that is absorbed more efficiently across the gut. I
Since these early times as the use of gabapentin has risen dramatically a more sinister side developed. Both gabapentin and pregabalin can produce feelings of relaxation, calmness and euphoria. By 2010, pregabalin had been listed as a new recreational psychoactive substance by EU agencies and in 2014, Public Health England and NHS England wrote to prescribers calling for a balanced and rational use of these medicines among fears the pregabalin was being sold on the black market by those in receipt of GP prescriptions.