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.
Gabapentin in patients with the pruritus of cholestasis: a double-blind, randomized, placebo-controlled trial.
Pruritus is defined as the second order of nociception, the first being pain; thus, there is a rationale to study gabapentin, a drug that increases the threshold to experience nociception. The aim of this double-blind, randomized, placebo-controlled trial was to study the effect of gabapentin on the perception of pruritus and its behavioral manifestation, scratching, in cholestasis. The participants were 16 women with chronic liver disease and chronic pruritus. Hourly scratching activity (HSA) was continuously recorded for up to 48 hours at baseline and on treatment for at least 4 weeks in an inpatient setting. The perception of pruritus was assessed by interviews and by a visual analog score (VAS) of pruritus recorded every hour while patients were awake. Patients were randomized to the study drug (gabapentin or placebo) at a starting dose of 300 mg orally per day in divided doses to a maximum of 2,400 mg or until relief from pruritus. Gabapentin was associated with an increase in mean HSA, in contrast to the placebo, which was associated with a decrease. The mean VAS decreased significantly among those taking the placebo and in some patients on gabapentin. In conclusion, gabapentin did not provide a significant therapeutic advantage over the placebo; in fact, it was associated with an increase in the perception of pruritus and in HSA in some patients.