A study exploring Flivas (naftopidil) in 117 patients with benign prostatic hyperplasia (BPH) demonstrates that long-term outcomes of the treatment vary widely.
The report, “Three-year outcome analysis of alpha 1-blocker naftopidil for patients with benign prostatic hyperplasia in a prospective multicenter study in Japan,” published in the journal Patient Preference and Adherence, indicated, however, that some of the participants quit the study once their problems disappeared.
Researchers at Sapporo Medical University in Japan attempted to analyze the outcomes of three years of treatment in men who had prostate symptoms graded as eight or higher on the international prostate symptom scores (IPSS), and were older than 50. Patients took either 50 or 75 mg of Flivas per day.
Only 21.4 percent of the initial 117 patients continued taking the medication throughout the length of the study. Among them, the prostate symptom scores, quality of life, BPH-associated problems, and maximum urinary flow rate were significantly improved.
Researchers also analyzed why the remaining 78.6 percent did not continue the study to its end, showing that 40.2 percent quit without stating a reason, while 38.5 percent provided reasons for leaving the study.
Most patients, 28.2 percent, quit because their symptoms improved. A large group, 17.9 percent, started taking another α1-blocking drug, and some added a 5α reductase inhibitor, or opted for surgery because the Flivas treatment was not sufficiently managing their symptoms.
Only 5.1 percent quit the study because of adverse events. The side effects experienced by those patients were postural hypotension, dizziness, and stomach discomfort.
In addition to the patients mentioned above who chose other treatments, Flivas failed to improve symptoms in 35 percent of patients. An analysis showed that age, prostate volume, and serum prostate-specific antigen (PSA) could each predict treatment failure. A more extensive analysis taking all the factors into account showed that only serum PSA levels predicted treatment failure.
Of the 50 patients who stopped taking Flivas during the study, only 26 percent reported that they needed additional treatment with α1-blocking drugs or surgery within three years. The other 74 percent reported that they did not experience severe symptoms such as acute urinary retention, and did not need additional treatment for their symptoms.