In 47 patients with
postherpetic neuralgia (PHN) who had never had an adequate trial of any
antidepressant, we performed a randomized, double-blind, parallel design trial comparing
desipramine,
amitriptyline, and
fluoxetine. Patients were titrated to a maximum of 150 mg/day for
desipramine and
amitriptyline and 60 mg/day for
fluoxetine over a 3-week period and then treated for an additional 3 weeks before tapering off study medication. A total of 38 subjects (81%) completed the entire trial. The modified intent-to-treat analysis of percent change in daily diary
pain intensity scores showed no significant differences among the 3 drugs (ANOVA P = .120).
Desipramine produced the greatest reduction in
pain intensity (47%), followed by
amitriptyline (38%) and
fluoxetine (35%). Clinically meaningful
pain relief (moderate or better) was significantly more likely with
desipramine (12/15 patients) than with
amitriptyline (9/17) or
fluoxetine (5/15); chi(2)P = 0.036). The 11 subjects using
opioids at study entry had smaller reductions in
pain than those not using concomitant
opioids. The
fluoxetine group had the highest noncompletion rate (33%), with 1 subject hospitalized for
hyponatremia. Although the magnitude of
pain reduction and the category
pain relief rating was not significantly different among the 3 drugs, the tricyclics
desipramine and
amitriptyline were well tolerated and provided clinically meaningful
pain relief in 53% to 80% of subjects.
PERSPECTIVE: