Calcipotriol has become a first-line treatment for psoriasis. Its efficacy and safety have been shown in many comparative clinical trials carried out in outpatients. In a comparative study in patients visiting the outpatient department once every 14 days, it was shown that calcipotriol was more effective and better tolerated compared with dithranol.
To compare the clinical efficacy of calcipotriol ointment with that of dithranol cream in a supervised treatment regimen.
In a multicentre randomized controlled trial in six centres in the Netherlands, 106 patients with chronic plaque psoriasis were included, 54 receiving calcipotriol ointment twice daily and 52 dithranol cream once daily. Patients were treated at the day-care centre, using the care instruction principle of daily visits during the first week and twice-weekly visits subsequently for up to 12 weeks.
This study failed to prove that calcipotriol is as efficacious as dithranol when used in a day-care setting (noninferiority test). The mean percentage reduction in Psoriasis Area and Severity Index from baseline to end of treatment was 57.0% in the calcipotriol group vs. 63.6% in the dithranol group. However, the two-sided test for superiority indicated no statistically significant difference between the treatment groups (P = 0.39). At the end of treatment, 15% of the patients treated with calcipotriol ointment and 25% of those treated with dithranol cream did not require any further treatment. Although calcipotriol ointment appeared to be more effective during the first 8 weeks, a difference was no longer apparent at 12 weeks. In comparison with the high number of drop-outs due to cutaneous side-effects in the calcipotriol group, the frequency of a tolerable degree of irritation appeared to be higher in patients treated with dithranol. However, concomitant corticosteroid treatment of dithranol irritation in seven patients may have contributed to this difference between both treatments. Moreover, patients receiving therapy with calcipotriol ointment experienced fewer application-related skin and subcutaneous tissue disorders than patients treated with dithranol cream: 21 of 53 (40%) and 37 of 52 (71%), respectively. This difference is statistically significant (P = 0.001).
The hypothesis that calcipotriol ointment might be at least as effective as dithranol cream in the day-care setting could not be proven in the present study. Whereas calcipotriol has become a mainstay in the routine outpatient treatment of psoriasis not requiring a day-care setting, dithranol treatment, being difficult as a routine outpatient therapy, has increased efficacy and improved tolerability if the treatment is carried out in a day-care setting.