The findings of this review indicate that the number of systemic and topical drugs used for the different subforms of pruritus is increasing. Different interventions have been shown to be effective in the treatment of pruritus of different origins. Nevertheless, an optimal therapy for pruritus is constrained due to the limited understanding of crucial itch mediators and receptors in the various subforms of itch. Ideal antipruritic therapies are still lacking, especially for palliative care patients.
This systematic review also indicates that there is insufficient evidence to give any concrete recommendations regarding treatment of pruritus in palliative care patients. Due to the very small sample sizes and poor methodological quality of the majority of studies that were included, the results of this review need to be interpreted with caution. Furthermore, the generalizability is questionable. Additional studies, and particularly carefully designed treatment trials, are needed to provide valid evidence for adequate treatment of pruritus in palliative care patients.
Low-dose doxepin for treatment of pruritus in patients on hemodialysis.
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.
                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.
                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.
                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.