Does amitriptyline improve the quality of life of adolescents with newly diagnosed irritable bowel syndrome?

In this small, short-term study, some adolescents with newly diagnosed irritable bowel syndrome experience improved quality of life when treated with amitriptyline (Elavil). (LOE = 2b)

Bahar RJ, Collins BS, Steinmetz B, Ament ME. Double-blind placebo-controlled trial of amitriptyline for the treatment of irritable bowel syndrome in adolescents. J Pediatr 2008;152:685-689.  [PMID:18410774]

Randomized controlled trial (double-blinded)

Foundation

Uncertain

Outpatient (specialty)

This 13-week study had 3 phases: 2 weeks of enrollment and baseline assessments; 8 weeks of intervention (amitriptyline or placebo); and 3 weeks of washout and final assessments. The 33 patients in this study, newly diagnosed with irritable bowel syndrome according to the Rome II criteria, were between the ages of 12 years and 18 years and were not receiving any treatment for depression, anxiety, or chronic pain. The amitriptyline dose, given at bedtime, was weight based: Patients weighing 30 kg to 50 kg received a 10-mg capsule; those weighing 50 kg to 80 kg received 20 mg; and those heavier than 80 kg received 30 mg. Each patient completed a set of self-administered inventories assessing quality of life, specific symptoms, pain impact scales, and visual analog scales for pain intensity and frequency. The authors don't report if they used intention to treat to analyze the data. Two patients dropped out of the study. The main outcome was improvement in overall quality of life. The baseline quality of life scores were significantly lower for the patients treated with amitriptyline. The authors report that the proportion of patients achieving at least a 15% improvement in quality of life scores was greater in patients receiving amitriptyline. (Many researchers believe that the minimum clinically important difference is between 15% and 20%.) Unfortunately, the authors present their outcomes in a crude graph that makes estimating the effectiveness difficult. It appears that at 6 weeks, 20% of patients treated with placebo improved compared with 40% of patients treated with amitriptyline. For weeks 10 and 13, it appears that no patients taking placebo improved, while 40% then 50% of patients treated with amitriptyline improved. The graph suggests the numbers needed to treat are 5, 2, and 2, respectively. Although these were statistically significant, the confidence intervals are likely to be wide because of the small size of the study. Finally, the authors report that fewer than half the eligible patients participated in the study; the negative publicity about antidepressants in adolescents limited participation.