Placebo Effects in the Pharmacological Treatment of Uncomplicated Benign Prostatic Hyperplasia

Abstract

In order to establish accurately the exact effect of any drug therapy for symptomatic benign prostatic hyperplasia (BPH) it is important to define the effect of placebo treatment. This effect was assessed by thoroughly analyzing the placebo arm, which included 101 patients, from a randomized, double-blind, placebo-controlled trial of the selective alpha-blocker alfuzosin and comparing the data with those of a variety of independent studies which followed a placebo group of patients with clinical BPH. Following 16 weeks of placebo treatment a decrease of 24% (p < 0.05) in Madsen-Iversen score and an increase of 14% (p < 0.05) in peak flow rate was demonstrated. The percentages of patients who reported worsening, improvement or no change in symptoms were 9.2%. 73.6% and 17.2% respectively. The maximal effect of placebo, approximately 40% reduction in symptom scores, is likely to be achieved within the first four to six months. After this, the placebo effect stabilizes and gradually wears off but is still present following 12 months of treatment. The duration of the placebo effect and the time until it has totally worn off, if ever, remains to be studied in long-term, placebo-controlled trials, including an untreated cohort. The present study emphasizes the importance of properly designed, double-blind, placebo-controlled studies in evaluating any pharmacological intervention in clinical BPH.

Key-words:

• benign prostatic hyperplasia (BPH)
• pharmacological treatment
• placebo
• natural history