Psychotropics in different causes of itch: systematic review with controlled studies

Abstract

Among the wide range of symptoms neglected or resistant to conventional treatments in clinical practice, itch is emerging gradually as a theme to be studied. Itch complaints and the negative effects in the quality of life are observed in several medical fields. Although the partially obscure pathophysiology, some researchers decided to check and test the use of psychotropic drugs in resistant itch to conventional topical treatments and antihistamines. The objective of this study was to evaluate scientific evidence in psychotropic use in the treatment of itch of various causes. This is a systematic review of scientific literature. The following databases were used: PubMed, Web of Science, Scopus and Scielo. Randomized controlled trials that should focus on treatment with psychotropic drugs of pruritus of various causes were the inclusion criteria. All articles were analyzed by the authors, and the consensus was reached in cases of disagreement. Fifteen articles were included after analysis and selection in databases, with the majority of clinical trials focusing on psychopharmacological treatment of itch on account of chronic kidney disease. Clinical trials with psychotropic drugs mostly indicated significant improvement in the itching. In most trials of chronic kidney disease as basal disease for itch, greater effectiveness was observed with the use of psychotropic drugs compared with placebo or other antipruritic. However, the small amount of controlled trials conducted precludes the generalization that psychiatric drugs are effective for itch of various causes.

European S2k Guideline on Chronic Pruritus

“…Antidepressants. Recent systematic reviews demonstrate evidence that antidepressants are effective particularly in refractory pruritus, pruritus in CKD, cholestasis or neoplasm (306), as well as in other forms of CP (307,308). Psycho-emotional factors are known to modulate the "itch threshold" (309).…”

Estrogen alleviates acute and chronic itch in mice

“…More in-depth subsequent studies are needed to clarify this issue. Furthermore, different animal models\interventions\observation methods affect the effects of estrogen ( 48 , 49 ), and there are some differences in the present and previous studies ( 30 ): i) The experimental animals in previous studies were rats, but mice were used in the current study; ii) The previous researchers used estradiol from 15 mm Silastic capsules containing crystalline 17β-estradiol with the blood concentrations of estradiol within the normal range of the estrus cycle in adult female rats from the previous studies. One to two months after surgery, rats were used for behavioural analysis.…”

“…The acute chemical itch can be relieved by scratching or antihistamine therapy, but the chronic itch is challenging to cure because the mechanisms are unclear, and the chronic itch is resistant to conventional treatments (e.g., antihistamines) ( 29 , 30 ). Numerous patients suffer from chronic itch, and the development of effective antipruritic drugs is imminent ( 31 ).…”