Low-dose doxepin for treatment of pruritus in patients on hemodialysis

Abstract

Introduction: Pruritus is one of the frequent discomforting complications in patients with end-stage renal disease. We prospectively evaluated the effectiveness of doxepin, an H1-receptor antagonist of histamine, in patients with pruritus resistant to conventional treatment.

Materials and methods: A randomized controlled trial with a crossover design was performed on 24 patients in whom other etiologic factors of pruritus had been ruled out. They were assigned into 2 groups and received either placebo or oral doxepin, 10 mg, twice a day for 1 week. After a 1-week washout period, the 2 groups were treated conversely. Subjective outcome was determined by asking the patients described their pruritus as completely improved, relatively improved, or remained unchanged/worsened.

Results: Complete resolution of pruritus was reported in 14 patients (58.3%) with doxepin and 2 (8.3%) with placebo (P < .001). Relative improvement was observed in 7 (29.2%) and 4 (16.7%), respectively. Overall, the improving effect of doxepin on pruritus was seen in 87.5% of the patients. Twelve patients (50.0%) complained of drowsiness that alleviated in all cases after 2 days in average. One patient refused to continue the treatment due to its sedative effect.

Conclusions: We suggest that doxepin, a tricyclic antidepressant with anti-H1 receptor effect, can help improve pruritus resistant to antihistamines in end-stage renal disease patients who undergo hemodialysis. A low dose of doxepin is safe while effective and its main adverse effect, drowsiness, is temporary and can be easily tolerated by the patients.