Both amitriptyline and duloxetine ease diabetic neuropathy
Reuters Health • The Doctor's Channel Daily Newscast
NEW YORK (Reuters Health) – Pain associated with diabetic neuropathy is improved to a similar degree with daily amitriptyline or duloxetine, according to the results of a cross-over trial conducted in India.
While both the tricyclic antidepressant, amitriptyline, and the selective serotonin norepinephrine reuptake inhibitor, duloxetine, are approved by the US Food and Drug Administration for the treatment of painful diabetic neuropathy, “An extensive search of literature did not reveal any head-to-head comparison of duloxetine with amitriptyline,” the authors comment in their paper.
To compare the efficacy and safety of the two agents, Dr. Anil Bhansali at the Postgraduate Institute of Medical Education and Research, Chandigarh, and colleagues conducted a 14-week trial involving 58 type-2 diabetic patients with painful diabetic neuropathy for at least a month.
Patients received each drug in random order for 6 weeks with a 2-week washout between switch-over. The medications were taken once daily at bedtime, and could be up-titrated at 2-week intervals from 10 to 50 mg for amitriptyline and from 20 to 60 mg for duloxetine.
The primary end point was the reduction in pain measured on a 0-100 visual analog scale. “Median pain score reductions of >50%, 25–50%, and
With amitriptyline, 55% of patients showed good improvement, 24% had moderate improvement, and 16% showed mild improvement, according to the report. Corresponding rates while receiving duloxetine were 59%, 22% and 9%.
“Overall pain relief of >30% was observed in 64 and 62% of patients with duloxetine and amitriptyline, respectively,” the authors note. While 48% of the patients said they preferred duloxetine and 36% preferred amitriptyline, the difference was not statistically significant.
Dry mouth was more often associated with amitriptyline than duloxetine (55% vs. 24%), while the most common adverse effects with duloxetine were constipation and somnolence, the researchers found.
All other secondary measures, such as sleep score and improvement in A1C, were similar with both drugs.
“In conclusion,” Dr. Bhansali and colleagues write, “both amitriptyline and duloxetine demonstrated comparable efficacy, safety, and tolerability in the management of painful diabetic neuropathy.” They add that a larger trial might possibly show one drug to be superior to the other.
Diabetes Care 2011.