Observer-blind, randomized, intrapatient comparison of a novel 1% coal tar preparation (Exorex®) and Calcipotriol Cream (Dovonex®) in the treatment of plaque type psoriasis.
Authors: S. Tzaneva, H. Hönigsmann, A. Tanew.
Division of Special and Environmental Dermatology, Department of Dermatology, University of Vienna Medical School, Austria.
In a recent pilot study a novel, patented fatty acid-based 1% coal tar preparation (Exorex®) has been found to be similar in efficacy to Calcipotriol Cream in the treatment of psoriasis.
Our aim was to investigate the therapeutic efficacy, safety and cosmetic acceptability of the new 1% coal tar preparation Exorex®, in comparison with Calcipotriol Cream in a larger patient cohort.
Patients and methods
Fourty patients with chronic plaque type psoriasis were included in this randomized, observer-blind, intrapatient comparison trial. In each patient two comparable target plaques were treated twice daily with 1% coal tar preparation or Calcipotriol Cream. At the onset of therapy and at weeks 2, 4, 6 and 8, the response to treatment was determined by the psoriasis severity index (PSI) that assesses the degree of erythema, infiltration and scaling of the psoriatic lesions on a five-point scale.
In addition, all treatment-related side-effects were recorded and cosmetic acceptability of both treatments was rated every second week by the patients. After complete or near complete clearing the patients were followed up until relapse or for a maximum period of 18 months.
Thirty-eight patients completed the study. At termination of the trial the mean ± SD baseline PSI score of 9.2 ± 1.5 was reduced to 3.0 ± 2.9 by 1% coal tar preparation and to 2.8 ± 2.7 by Calcipotriol Cream.
The mean PSI reduction between baseline and final assessment did not differ significantly between 1% coal tar preparation and Calcipotriol cream (P = 0.77). The mean intraindividual difference in reduction of PSI score between 1% coal tar preparation and calcipotriol was 0.1 score points (95% confidence interval -0.84 to +0.63). No difference between either preparation was observed with regard to time until relapse. Itching was caused by 1% coal tar preparation in four patients and by Calcipotriol Cream in one patient. Unpleasant odour or staining of the 1% coal tar preparation was reported by six patients, whereas one patient complained about the smell of the Calcipotriol Cream.
The novel 1% coal tar preparation was found to be comparably as effective as Calcipotriol Cream in treating psoriasis. Tolerability and cosmetic acceptability was better for Calcipotriol Cream. Taking into consideration that the coal tar preparation is considerably less expensive than Calcipotriol Cream this new product appears as a very useful topical medication for chronic plaque type psoriasis.
This study was supported by a grant from Meyer Zall Laboratories, Owner and Patent Holder of the Exorex® and Linotar® brands, George, South Africa.
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Source: British Journal of Dermatology. Volume 149 (2003), Pages 350-353.
Web link to full text: https://pubmed.ncbi.nlm.nih.gov/12932242/