Low-dose amitriptyline as an adjunct to opioids for postoperative orthopedic pain: a placebo-controlled trial

Tricyclic antidepressants (TCAs) have been found to be useful in the management of a variety of chronic pain conditions, although there is little published regarding the potential efficacy of this class of drug as an adjunct for the control of acute postoperative pain and related symptoms. Twenty-eight patients undergoing total hip or knee arthroplasty completed a randomized, placebo-controlled, double-blinded trial of 50 mg of amitriptyline p.o. HS on postoperative days 1, 2 and 3 while using patient-controlled morphine or meperidine analgesia (PCA). Visual analog (VAS) and numerical verbal (NVS) pain ratings, sedation scores, sleep quantity/quality scores, and sense of well-being scores were assessed twice daily on each of the days succeeding amitriptyline/placebo use. Hourly opioid use was recorded and transcribed from the memory of the PCA devices in use. Mean scores in the amitriptyline group for pain NVS were greater (P < 0.05) (higher score = greater pain) on day 1 and greater on day 2 for the pain VAS. Mean scores for sense of well-being were greater (P < 0.05) (higher score = better sense of well-being) for the placebo group on days 1 and 2. On days 2 and 3, sleep scale variable mean scores were worse in the placebo group (P < 0.025). There were no other statistically significant differences between the control and active drug groups for any of the outcome variables measured. We conclude that amitriptyline at the dose prescribed is no different than placebo in altering the majority of postoperative symptom variables studied in the sample study population but caused no significant adverse effects.(ABSTRACT TRUNCATED AT 250 WORDS)