A drug used to treat epilepsy and chronic pain after shingles also appears to be effective for another persistent condition: chronic cough.
About 1 in 10 people suffers from chronic cough, and for many the cause is unknown.
Chronic cough is a cough that lasts for longer than eight weeks. Treatment tends to focus on the underlying cause of the cough, which may be due to conditions like asthma, acid reflux, or postnasal drip. The condition is increasingly common, poorly understood, and difficult to treat, experts tell WebMD.
"Chronic cough can have a profound impact on quality of life, but most people, including many physicians, know very little about it," says cough researcher Kian Fan Chung, MD, of Imperial College in London. He was not involved with the research.
Chronic Cough Improved With Gabapentin
In the new study, published in the journal Lancet, researchers in Australia report that the epilepsy drug gabapentin (Neurontin) reduced cough severity in many people with chronic cough who did not respond to other treatments.
The drug may work by calming overstimulated nerves believed to play a role in chronic cough, researchers say.
Gabapentin can also be used to treat postherpetic neuralgia (chronic pain after shingles), in which abnormal sensitivity to pain is thought to be caused by increased excitability of the central nervous system.
Because unexplained chronic cough shares many characteristics with these pain conditions, researchers speculated that the drugs may work for cough as well as pain.
The study included 62 people with chronic cough of at least eight weeks' duration. Most did not improve with other treatments, and many had no identified cause for their coughs.
They were assigned to receive either gabapentin or a placebo for 10 weeks.
Gabapentin Well-Tolerated
After treatment, more gabapentin-treated patients reported reductions in cough frequency and severity.
Noticeable improvements in quality-of-life scores were reported in 74% of the gabapentin-treated patients vs. 46% of those in the placebo group.
"Gabapentin is effective, well-tolerated, and has few drug interactions," writes researcher Nicole M. Ryan of the University of Newcastle in New South Wales, Australia. Nausea and fatigue were the most commonly reported side effects.
She added that because the drug's safety is well-established, it should be considered for patients whose chronic cough does not respond to other drugs.
In an editorial published with the study, Chung agreed.
"These results suggest that gabapentin is worth trying in patients with [difficult-to-treat] chronic cough and should provide the impetus to pursue similar trials of other drugs developed to suppress cough sensation pathways," he writes.
Chung says more effective treatments for chronic cough are badly needed.
"The treatments we have been using really don't work very well for some patients," he says.
The study was funded by the National Health and Medical Research Council of Australia and the Hunter Medical Research Institute in Newcastle, Australia.
Salynn Boyles - WebMD
