Targeted Use of Placebo Effects Decreases Experimental Itch in Atopic Dermatitis Patients: A Randomized Controlled Trial.

Abstract

Evidence from pain research shows that the effectiveness of active pharmacological treatments can be enhanced by placebo effects. The "open drug administration" is superior to "hidden drug administration.​" In a randomized controlled trial, we aimed to show that the targeted use of placebo effects increases the efficacy of an antihistamine (dimetindene) infusion in participants with atopic dermatitis. We openly infused dimetindene (drug) in full sight with information (intervention group 1: OPEN-DRUG+INST), openly infused drug with an additional classical conditioning learning experience (intervention group 2: OPEN-DRUG+INST+COND) or infused drug without any information or sight (i.e., hidden administration (control group 1: HIDDEN-DRUG)). Control group 2 received a placebo infusion (saline) declared as dimetindene and also experienced the conditioning experience (PLAC+INST+COND). Itch was experimentally induced with histamine via a skin prick test. Outcome was assessed at the subjective (primary end point: experimental itch intensity, numeric rating scale), and objective level (secondary end point: wheal size, mm2 ). Experimental-induced itch intensity decreased in all groups but at different rates (P < 0.001). The groups with the open administration, whether it was dimetindene or placebo, had significantly stronger reductions in itch compared to the HIDDEN-DRUG group (OPEN-DRUG+INST+COND: P < 0.001; OPEN-DRUG+INST: P = 0.009; and PLAC+INST+COND: P < 0.001). Additional drug conditioning mediated via expectation led to a stronger reduction of itching (P = 0.001). Results on wheal size were similar (P = 0.048), however, no significant difference between the HIDDEN-DRUG group and the PLAC+INST+COND group (P = 0.967) was found. We conclude that specifically generated targeted placebo effects can significantly increase the action of a drug (dimetindene) and should be used in clinical practice.

• Authors: Ariane Sölle, Margitta Worm, Fabrizio Benedetti, Theresa Sabine Bartholomäus, Lena Schwender-Groen, Regine Klinger
• Journal: Clinical pharmacology and therapeutics (Clin Pharmacol Ther) Vol. 110 Issue 2 Pg. 486-497 (08 2021) ISSN: 1532-6535 [Electronic] United States
• PMID: 33894061 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
• Copyright: © 2021 The Authors. Clinical Pharmacology & Therapeutics published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.

Chemical References

• Histamine H1 Antagonists, Non-Sedating
• Dimethindene
• Histamine

Topics

• Adolescent
• Adult
• Aged
• Conditioning, Classical
• Dermatitis, Atopic (complications, drug therapy, physiopathology)
• Dimethindene (administration & dosage, therapeutic use)
• Double-Blind Method
• Female
• Histamine
• Histamine H1 Antagonists, Non-Sedating (administration & dosage, therapeutic use)
• Humans
• Infusions, Intravenous
• Male
• Middle Aged
• Placebo Effect
• Pruritus (chemically induced, drug therapy, physiopathology)
• Skin (pathology)
• Treatment Outcome
• Young Adult