Intermittent high-dose dexamethasone-cyclophosphamide therapy for pemphigus

Abstract

Since 1982, we have treated 79 pemphigus patients with an arbitrarily designed regimen of 100 mg dexamethasone dissolved in 5% glucose given by an intravenous infusion over 1 h, daily on 3 consecutive days and in addition, 500 mg cyclophosphamide on day 1 only. The intermittent high doses (IHD) of dexamethasone are repeated every 2-4 weeks, and the patient continues to take 50 mg/day oral cyclophosphamide. This treatment is divided into four phases. During Phase I, the patient continues to develop relapses of pemphigus a variable number of days after IHD, but the lesions heal up quickly after IHD. These relapses become progressively milder and stop after a few months, but the IHD are continued once a month for 6-9 months (Phase II). In the next phase (Phase III), the monthly IHD are stopped, and the patient continues to tak 50 mg/day cyclophosphamide orally. After approximately 1 year this maintenance treatment is withdrawn and the patient is observed for any relapse (Phase IV). Of the 79 patients treated, 10 patients have been lost to follow-up and two have died, one due to leukopaenia caused by inadvertent additional administration of methotrexate, and the other of an unknown cause. Of the remaining 67 patients, 25 are off treatment (Phase IV), 25 are taking only 50 mg cylcophosphamide daily (Phase III), ten are also in remission, but still receiving intermittent high doses of dexamethasone-cyclophosphamide (Phase II), and seven still have active disease (Phase I). The remissions are long lasting, being already more than 2 years in 17 patients (maximum 46 months), 1-2 years in 11 and less than 1 year in 32. Side-effects of corticosteroids and cyclophosphamide are minimal and not clinically significant except for increased susceptibility to infections.