Treatment of recurrent oro-genital ulceration with low dose of thalidomide. Pilot study in 17 patients

Purpose. - Though thalidomide in a dosage of 100 mg/day is the standard tre atment for recurrent oral and genital ulcers (OGU), its toxicity would be l ess important with lower dosage, while its efficacy would be identical. Fur thermore, duration of treatment might be a major risk factor for the develo pment of subsequent polyneuropathy. To determine the dosage of thalidomide leading to the best efficacy/toxicity ratio, a pilot study was conducted fr om 1993 to 1996. Methods. - Seventeen patients with OGU (mean age: 43 years, sex-ratio: 12:5 ) were included in the study and presented either recurrent oral ulceration s (8 patients), oro-genital ulcerations (3 patients), Behcet disease (4 pat ients), or recurrent OGU associated with leukemia (2 patients). The initial dosage of thalidomide was 50 mg/day (1 tablet) for 1 month. If the patient 's condition improved, the dosage was reduced to one tablet every other day for 1 month and one tablet every 3 days thereafter. Nerve conduction studi es (EMG) were performed at inclusion in the study and every 6 months therea fter. Results. - Among the 17 patients, remission was observed in ten patients wi thin the first month of treatment and the condition of seven patients impro ved. Complete remission was observed in six patients after a 2-month treatm ent and in one patient after 4 months. A 200-mg/8 days dosage induced prolo nged remission in 12 patients. Among them, ten patients received a 150-mg d osage over 8 days thereafter and disease relapsed in four of them. Among th e six patients who received a 100-mg dosage over 8 days, only one relapse w as observed. EMG showed a decrease in sensory nerve action potentials in si x patients after 8 months and a half on average. Only three patients had to discontinue their treatment due to the occurrence of either paresthesia (2 patients) or areflexia (1 patient). Our study shows that initially a 50-mg /day dose is efficacious in the treatment of OGU and that administration of one tablet every 2 or 3 days is efficacious in more than 60% of the patien ts to maintain remission. Conclusion. - A dosage of 50 mg/day is initially efficacious in most cases, provided that the patient is carefully followed up to allow early detectio n of potential peripheral neuropathy.