A phase II study of venlafaxine for the treatment of hot flashes in men undergoing androgen deprivation for prostate cancer

Abstract

8148 \(\underline{\mathrm{Background:}}\)Vasomotor hot flashes are a common and distressing problem in men undergoing androgen deprivation therapy (ADT) for prostate cancer. Venlafaxine reduces both the incidence and severity of hot flashes in women with breast cancer. Data in men with prostate cancer on ADT are scarce. \(\underline{\mathrm{Methods:}}\) Eligible patients underwent ADT and had at least 14 hot flashes per week of sufficient severity to desire intervention. The initial daily dose was 75 mg, but the study was amended after enrolling the first 4 patients to 37.5 mg because of grade 2 toxicity by one patient. Data was collected by daily questionnaires during an initial 1-week baseline period and then weekly for the first 4 weeks during treatment with venlafaxine. Primary end point was reduction of greater than 50% in the weekly hot flash score (a composite score of number of hot flashes and severity), during the last week as compared to baseline. Toxicity data was collected each week. Patients completed a Beck Depression Inventory (BDI) and a single-item global quality-of-life (QOL) question each week. All outcomes were analyzed using repeated measures analysis of variance models. \(\underline{\mathrm{Results:}}\) Twenty patients were enrolled. Three patients did not complete any of the weekly questionnaires and were inevaluable. Of the 17 evaluable patients, 12 (70.6%) had more than 50% reduction in the hot flash score. Weekly hot flash scores were reduced by an average of 58% (95% C.I. 0.49–0.66) from baseline to end of study. The average weekly frequency of hot flashes was 58.6 at baseline and was reduced to 29 by end of study (p<.0001). Overall QOL data was available for 15 patients, and increased from baseline to end of study by an average of 1.3 points (p=.01). BDI scores were available for 11 patients and improved by an average of 3.5 points (p=.011). Only one patient had grade 2 dizziness and fatigue toxicity. Thirteen of the 17 patients (76.4%) said they would wish to continue the medication at the end of the study. \(\underline{\mathrm{Conclusions:}}\) Venlafaxine was well tolerated and effective in mitigating hot flashes in this patient population. No significant financial relationships to disclose.