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.
Topical capsaicin for treatment of hemodialysis-related pruritus.
Pruritus is a significant problem for many patients undergoing long-term hemodialysis. Topical capsaicin depletes and prevents the reaccumulation of substance P in peripheral sensory neurons. Substance P functions in the transmission of pain and probably itch sensations. An open-label, uncontrolled trial and a double-blind, vehicle-controlled trial were conducted to evaluate the efficacy and safety of capsaicin 0.025% cream in the treatment of localized areas of pruritus in patients undergoing long-term hemodialysis. Eight of nine evaluable patients in the open-label trial reported marked relief or complete resolution of itching during the study period, and two of five evaluable patients in the double-blind trial reported complete resolution of itching in the capsaicin-treated arm with no or minimal improvement in the vehicle-treated arm. Twelve patients in the open-label trial and two in the double-blind trial were unevaluable. No serious treatment-related adverse reactions occurred.