Neuropathic pain (NP) is difficult to treat. Multiple mechanisms are involved in the pathophysiology of NP and there is a rationale for combining analgesics with different modes of action.
Building on earlier reports supporting combination therapy, US researchers evaluated the combination of morphine, a narcotic pain reliever, and nortriptyline, a tricyclic antidepressant, in 39 patients with NP.
Results of this randomised, double-blind, crossover study, published in Pain
, found that average daily pain scores were reduced significantly more with combination therapy than with either nortriptyline or morphine alone. Scores on the Brief Pain Inventory (average and present pain) were also significantly lower for combination versus monotherapy. The most frequent adverse events were constipation, dry mouth and somnolence.