Comparison of Calcipotriene (Dovonex) With a Coal Tar Emulsion (Exorex) in Treating Psoriasis in Adults: A Pilot Study
Authors and Description
Veronikis, IE, Malabanan, AO, Holick, MF. A preliminary study comparing calcipotriol (Dovonex) and coal tar emulsion (Exorex) in the treatment of psoriasis in adults. Arch Dermatol.1999; 135: 474-475.
Coal tar, a mixture of at least 10,000 components, has long been shown to have efficacy in the treatment of psoriasis.1 Exorex (IMX Pharmaceuticals Inc, Boca Raton, Fla) is a new coal tar–based, Food and Drug Administration–sanctioned psoriasis medication deemed safe for sensitive skin. Calcipotriene (Dovonex; Westwood-Squibb Pharmaceuticals, Buffalo, NY) is an active cholecalciferol analog, useful in psoriasis therapy, but which can cause dermatitis in sensitive areas.2 We conducted a pilot study comparing the therapeutic efficacy and safety of Dovonex (hereinafter, “calcipotriene”) and Exorex (hereinafter, “1% coal tar emulsion”) in treating psoriasis.
Patients and Methods
Twenty adult patients with plaque-type psoriasis (16 men and 4 women, aged 18-75 years) were enrolled in this single-blind intrapatient comparison study. Five dropped out after baseline evaluation. Each patient underwent a blood chemistry analysis, a complete blood cell count, and urinalysis at baseline and monthly through the study’s duration. Two similar 50-cm2 psoriatic lesions were selected in each patient for twice-daily treatment with either 0.1 g of calcipotriene or 0.1 g of the 1% coal tar emulsion followed 2 minutes later by application of moisturizing cream (Exorex Stabilizing Cream; IMX Pharmaceuticals Inc). All treated lesions were photographed at baseline and at every visit. Erythema, scaling, and plaque thickness of the treated lesions were evaluated using a 4-point scale (0, no lesion; 2, mild; 4, moderate; 6, severe). After 2 months, 4-mm punch biopsy specimens were taken of the lesions treated with calcipotriene, those treated with the 1% coal tar emulsion, and normal skin.The patients were treated for a mean ( SD) 64.47.92 days (range, 12-125 days). Statistical significance was assessed by the 2-tailed Student t test for paired differences.
The mean SD pretreatment severity scores for erythema, scaling, and plaque thickness were 4.1 0.3, 4.1 0.4, and 3.7 0.4, respectively. After treatment with the 1% coal tar emulsion, the scores for erythema, scaling, and plaque thickness decreased to 2.2 0.3 (a 41% 8% decrease; P<.001), 1.9 0.5 (a 56% 10% decrease; P<.01), and 2.4 0.4 (a 31% 13% decrease; P<.05), respectively. After treatment with calcipotriene, scores for erythema, scaling, and plaque thickness decreased to 2.1 0.2 (a 42% 8% decrease; P<.001), 1.6 0.4 (a 63% 9% decrease; P<.001), and 1.7 0.3 (a 47% 9% decrease; P<.001). No significant intertreatment difference was observed in improvement of scaling, erythema, or plaque elevation. No adverse effects or laboratory abnormalities were noted after treatment with either medication.
This pilot study suggests that this preparation of 1% coal tar emulsion is about as effective as calcipotriene in treating psoriasis. In this study, which was not vehicle controlled, the clinical improvement with either medication was comparable and substantial after 1 month of treatment. Long-term effects of 1% coal tar emulsion are not yet known, and further studies are indicated.
Irini E. Veronikis, MD
Alan O. Malabanan, MD
Michael F. Holick, PhD, MD
Department of Medicine
Boston University School of Medicine
715 Albany St, M-1013
Boston, Mass 02118
1. Silverman A, Menter A, Hairston JL. Tars and anthralins. Dermatol Clin. 1995;13:817-833. MEDLINE
2. Kragballe K. Treatment of psoriasis by the topical application of the novel cholecalciferol analogue calcipotriol. Arch Dermatol. 1989;125:1647-1652. MEDLINE
3. British Journal of Dermatology. Volume 149 (2003), pages 350-353.
Supported in part by grant M01RR00533 from the National Institutes of Health, Bethesda, Md, and funding from IMX Pharmaceuticals Inc, Boca Raton, Fla.
Presented in part at the 58th Annual Meeting of the Society for Investigative Dermatology, Washington, DC, April 26, 1997.