Gabapentin And Lyrica Not Effective For Some Pain, But Over-Prescribed And Increasingly Abused, Says Researchers
According to Canadian researchers, there is little evidence that medications intended to treat nerve pain, such as Lyrica (pregabalin) and Neurontin (gabapentin) are effective at managing lower back pain.
The research, which was recently published in the journal PLoS Medicine, reviewed eight clinical studies, and investigators also found that the drugs have a “significant risk of adverse effects.”
These medications are in a class of drugs called gabapentinoids and are often used as alternatives to opioids in the treatment of neuropathic pain, such as fibromyalgia. However, they have been increasingly been prescribed for other pain conditions, such as chronic pain, despite the lack of evidence for their effectiveness.
Lead author Harsha Shanthanna, MD, an assistant professor at McMaster University in Hamilton, Ontario:
“Despite their widespread use, our systematic review with meta-analysis found that there are very few randomized controlled trials that have attempted to assess the benefit of using gabapentin or pregabalin in patients with chronic low back pain.”
“They necessitate prolonged use and are associated with adverse effects and increased costs. Recent guidelines from the National Health Service (NHS), England, expressed concerns on their off-label use, in addition to the risk of misuse.”
Researchers revealed in the study that gabapentin resulted in “minimal improvement” in back pain and that pregabalin was “inferior” to other analgesics. Although there were no fatalities or hospitalizations reported in any of the data, both drugs were linked to increased risk of dizziness, fatigue, vision problems, and reduced mental activity.
About Gabapentin And Lyrica
Both Gabapentin and Lyrica are manufactured by Pfizer and are two of the company’s top selling drugs. The Food and Drug Administration approved Lyrica to treat fibromyalgia, diabetic nerve pain, post-herpetic neuralgia, and spinal cord injuries.
As noted, it is often prescribed off-label to treat other types of chronic pain, such as lower back pain.
Similarly, Neurontin is also indicated by the FDA for the treatment of neuropathic pain due to shingles and is also approved to treat epilepsy. Still, it is often prescribed off-label to treat attention deficit hyperactivity disorder, depression, migraines, and fibromyalgia.
In fact, according to some data, more than 90% of Neurontin sales may be for off-label usage, and Pfizer has paid nearly $1 billion in fines to settle civil and criminal allegations that it has marketed Neurontin to treatment conditions unapproved by the FDA.
Recently public health outcry over the opioid epidemic, addiction, and overdoses has, in part, helped to drive up the sales of both pregabalin and gabapentin. Indeed, the Centers for Disease Control and Prevention have recommended both drugs as alternative treatments to opioid medication. Prescriptions for gabapentin increased by nearly 50% to 64 million from 2001-2016.
FDA Seeks Public Comment on Abuse of Lyrica
In related news, last week the FDA announced that it was seeking public comment on reports that pregabalin is being misused.
This action came as a response from the World Health Organization, who stated it might put international restrictions on the drug to decrease abuse and diversion. The FDA has until the end of next month to respond.
The FDA stated the following in a notice published in the Federal Register:
“Reports indicate that patients are self-administering higher than recommended doses to achieve euphoria…While effects of excessively high doses are generally non-lethal, gabapentinoids…are increasingly being identified in post-mortem toxicology analyses.”
Pregabalin is currently classified as a Schedule V controlled substance under the Controlled Substances Act, which indicates that it tends to have a low potential for misuse.
Are Pregabalin and Neurontin Dangerous? Are They Really Being Abused?
Although these medications do not tend to cause euphoria on their own, some patients have found they enhance the effects of other drugs, such as prescription opioids and heroin, and they are sometimes found in toxicology reports as a contributing factor to overdose.
As reported in the journal Addiction, overdose fatalities related to both opioids and gabapentoids increased to 137 in 2015, up from less than one death per year on average before 2009. The spike also closely aligned with a significant increase in the number of both pregabalin and gabapentin prescriptions.
The study concluded:
“For heroin users, the combination of opioids with gabapentin or pregabalin potentially increases the risk of acute overdose death through either reversal of tolerance or an additive effect of the drugs to depress respiration.”
Recently, a small study of pain clinic patients revealed that as many as 1 in 5 patients are taking gabapentin illicitly (without a prescription).
Poluru Reddy, Ph.D., at the annual meeting of the American Association for Clinical Chemistry in Philadelphia:
“The high rate of misuse of this medication is surprising, and it is also a wakeup call for prescribers. Doctors don’t usually screen for gabapentin abuse…[but] these findings reveal that there is a growing risk of abuse and a need for more robust testing.”
~ G. Nathalee Serrels, M.A., Psychology
https://s3.amazonaws.com/public-inspection.federalregister.gov/2017-17119.pdf Gabapentin and Lyrica