Duration of improvement in psoriasis after treatment with tazarotene 0.1% gel plus clobetasol propionate 0.05% ointment: comparison of maintenance treatments

Fifty patients were enrolled in a double-blind, randomized, parallel-group study designed to determine whether tazarotene may have a role in maintenan ce therapy for psoriasis. The patients had stable moderate-to-severe plaque psoriasis on up to 15% of their body surface area, on sites other than the face and scalp. Their mean age was 55 years and the majority had had psori asis for more than 10 years. Washout periods were: 2 weeks for topical drug s, 4 weeks for UVB or PUVA treatment, and 8 weeks for systemic drugs that m ight, alter the course of psoriasis. For the initial open-label treatment phase, patients applied tazarotene 0.1 % get plus clobetasol propionate 0.05% ointment for 6 weeks. The frequency of application of both medications was initially once daily and then was ta pered to ensure gradual weaning. Thus, during weeks 1 and 2, patients appli ed tazarotene each morning and clobetasol propionate each evening. During w eeks 3 and 4, patients applied tazarotene each morning and clobetasol propi onate each Tuesday, Thursday, and Saturday evening. Finally, during weeks 5 and 6, patients applied tazarotene each Monday, Wednesday, and Friday morn ing, and clobetasol propionate each Tuesday and Thursday evening. For the subsequent double-blind maintenance phase, patients were randomized to receive one of three maintenance regimens for 20 weeks - tazarotene/clo betasol (tazarotene 0.1% gel on Monday, Wednesday, and Friday mornings, plu s clobetasol propionate 0.05% ointment on Tuesday and Thursday evenings), t azarotene/vehicle (tazarotene 0.1% get on Monday, Wednesday, and Friday mor nings, plus white petrolatum on Tuesday and Thursday evenings), and vehicle (tazarotene gel vehicle on Monday, Wednesday, and Friday mornings plus whi te petrolatum on Tuesday and Thursday evenings). Patients were instructed to apply a thin film of medication to their psoria tic plaques. Emollient use was permitted, but other topical formulations an d excessive exposure to ultraviolet light were not. Efficacy was evaluated - at baseline, every 2 weeks during the initial trea tment phase, and every 4 weeks during the maintenance phase - in terms of o verall disease severity, plaque elevation, scaling, erythema, pruritus, and global response to treatment. The first four of these were rated by the ph ysician as 0 = none, 2 = mild, 4 = moderate, 6 = severe, and 8 = very sever e. Pruritus was rated as 0 = none, 1 = trace, 2 = mild, 3 = moderate, 4 = m arked, and 5 = severe. Global response was rated as 0 = cleared, 1 = almost cleared (similar to 90% improvement), 2 = marked (similar to 75%) improvem ent, 3 = moderate (similar to 50%) improvement, 4 = slight (similar to 25%) improvement, 5 = unchanged, and 6 = worse. Analysis of variance and the Student's t-test were used to compare maintena nce regimens (P less than or equal to 0.05). In the maintenance phase, the last recorded score for each patient was carried forward to all subsequent visits.