Combining morphine and nortriptyline has been found to successfully relieve chronic neuropathic pain in 87% of patients, and significantly better than with either drug alone, according to a study published in the journal Pain.

“Chronic pain is an increasingly common problem and can exert disastrous personal, societal, and socio-economic impacts on patients, their families, and their communities,” said lead author Ian Gilron, MD, Queen’s University School of Medicine, and Kingston General Hospital, Kingston, Ontario. “Current neuropathic pain treatments are ineffective or intolerable for many sufferers so this new evidence supporting the morphine-nortriptyline combination is important news for patients.”

During the study, average daily pain was measured using a patient’s numerical rating of pain on a validated scale from 0 to 10. It was found that average daily pain before treatment was 5.6, which dropped to 2.6 when the patient was receiving the drug combination. On average, patients taking nortriptyline and morphine alone rated their pain at 3.1 and 3.4, respectively.

Common side effects for both drugs, which can include constipation and dry mouth, did not worsen during the combination treatment.

“It’s important to remember that we don’t want to completely eliminate patients’ ability to sense pain as it’s a warning system for us, but we do want to find the right balance of pain relief and drug side effects,” said Dr. Gilron. “Morphine and nortriptyline are excellent candidates for pain management because of the extensive research conducted on them, their low cost, and widespread availability all over the world.”

In the double-blind, randomised crossover study, every patient had the opportunity to try every 1 of the 3 treatments — the combination, morphine alone or nortriptyline alone — in each of the three 6-week treatment periods. Throughout each treatment period, patients attended follow-up assessments to record their pain levels and side effects.