Bad News Continues for Non-Opioid Analgesics
/By Pat Anson
The bad news keeps piling up for non-opioid analgesics that are often touted as safer and more effective alternatives to opioid pain medication.
A large new study found that pregabalin (Lyrica) raises the risk of heart failure in older patients, while Vertex Pharmaceuticals said it was stopping development of an experimental drug for post-operative pain because it was less effective than a low dose of hydrocodone.
The pregabalin study, recently published in JAMA Network Open, compared the drug to gabapentin (Neurontin) among Medicare patients with chronic non-cancer pain. Both pregabalin and gabapentin are gabapentinoids, a class of nerve medication that was originally developed to prevent seizures in epileptic patients.
Because they are not opioids and widely perceived as safer, both drugs are now widely prescribed for a variety of pain conditions, usually off-label.
In a subset of patients with cardiovascular disease, researchers found that hospitalizations and emergency department visits for heart failure were more common in pregabalin users compared to patients on gabapentin. The difference wasn’t significant (18.2 visits vs 12.5 per 1,000 person-years), but it was enough for researchers to recommend caution when prescribing pregabalin.
“Practicing clinicians should undertake a careful assessment of ongoing cardiovascular risk factors and perform adequate risk-benefit counseling for older patients before prescribing pregabalin for chronic pain,” wrote lead author Elizabeth Park, MD, Columbia University Irving Medical Center.
Pregabalin is believe to be riskier because it binds to calcium channels associated with heart failure and arrhythmias. Both the American Heart Association and European Medicines Agency already list pregabalin as a drug that increases the risk of heart failure.
"The study serves as an important reminder that not all gabapentinoids are created equal and that in the pursuit of safer pain control, vigilance for unintended harms remains paramount," said Robert Zhang, MD, and Edo Birati, MD, in an accompanying editorial.
"For older adults with chronic pain, particularly those with cardiovascular disease, clinicians should weigh the potential cardiovascular risks associated with pregabalin against its analgesic benefits. This is particularly relevant given the growing use of gabapentinoids in older populations and ongoing polypharmacy issues in this age group."
The research doesn’t give gabapentin a clean bill of health, since it also raises the risk of heart failure in older patients – just not as much as pregabalin. Last month another study found that gabapentin increases the risk of dementia and cognitive impairment.
Researchers have long been concerned about the effects of gabapentinoids on the brain, while many patients have complained the drugs cause brain fog, dizziness, weight gain and mood changes. Despite warnings that they are overprescribed for conditions they were never intended to treat, the use of gabapentinoids continues to grow in the United States.
New Analgesic No Better Than Vicodin
The new analgesic being developed by Vertex Pharmaceuticals – called VX-993 -- will apparently never reach patients, after the company announced disappointing results from a Phase Two clinical trial. VX-993 is a non-opioid that blocks pain signals in peripheral nerves before they reach the brain, which means it doesn’t have the same “liking” effects of opioids, which can lead to addiction.
When given to patients recovering from bunionectomy surgery, VX-993 was slightly more effective than a placebo in reducing post-operative pain, but provided less pain relief than a low dose of a hydrocodone/acetaminophen combination (Vicodin).
“Based on these results, as well as the totality of preclinical data and results from our previous bunionectomy clinical studies, VX-993 is not expected to be superior to our existing NaV1.8 inhibitors and therefore we will not be advancing it as monotherapy in acute pain,” Carmen Bozic, MD, Executive Vice President and Chief Medical Officer at Vertex, said in a statement.
VX-993 acts similarly to Journavx (suzetrigine), a non-opioid also developed by Vertex that acts on peripheral nerves. Journavx was recently approved by the FDA to treat moderate to severe acute pain, despite lackluster results in clinical trials that also showed it was no more effective than Vicodin.
The FDA’s approval of Journavx coincides with implementation of the NOPAIN Act, which makes non-opioid analgesics in outpatient surgical settings eligible for higher Medicare reimbursement rates. Journavx costs about three times as much as Vicodin.
