As effective as combination treatment with anticholinergic agents for BPH storage symptoms.
Naftopidil is effective first-line monotherapy for patients with storage symptoms associated with benign prostatic hyperplasia (BPH), according to researchers in Japan.
Naftopidil is a second-generation a1-adrenoceptor antagonist with a high affinity for the a1d-adrenoceptor subtype. Naftopidil has been proven effective in the treatment of bladder outlet obstruction in pa-tients with BPH and is approved in Japan for clinical use in patients with
BPH. It is not yet available in the United States.
In a recent study, 101 patients with BPH and storage symptoms as the chief complaint were randomized to receive 25-75 mg/day of naftopidil with or without an anticholinergic agent (10-20 mg/day of propiverine hydrochloride or 2-6 mg/day of oxybutynin hydrochloride) for 12 weeks.
Therapeutic efficacy was determined using the International Prostate Symptom Score (IPSS), quality of life (QOL) index, maximum flow rate (Qmax), and residual urine volume (RUV) measured by transabdominal ultrasonography.
Significant improvements in IPSS scores for incomplete emptying, urinary frequency, nocturia, and weak urinary stream were achieved in both the naftopidil monotherapy and combination therapy groups with no significant differences between the groups, the researchers reported in the International Journal of Urology (2006;13:1280-1285).
Significant improvements in urgency and straining were observed in the combination therapy group, but not in the monotherapy group. Conversely, intermittency was significantly improved in the monotherapy group, but not in the combination therapy group.
For both groups, total IPSS was significantly improved between pre- and post-treatment. The QOL index was improved in the monotherapy and combination therapy group. Qmax and RUV tended to improve in both groups with no significant differences between the groups during treatment, according to Yoshio Kawachi, MD, of Juntendo University Urayasu Hospital in Chiba, and his colleagues.
At the end of treatment, median RUV was significantly greater in the combination therapy group than in the naftopidil monotherapy group (45.0 vs. 13.5 mL). An increase in RUV of greater than 50 mL was observed in 5% of the monotherapy group and 22.9% of the combination treatment group.
The frequency of adverse events did not differ significantly between the monotherapy and combination therapy group (4.4% and 7.3%, respectively). All adverse events were mild, and the most frequently reported adverse events were nausea, dizziness, and abdominal fullness.
Naftopidil monotherapy was equally effective compared with combination therapy and was more tolerable in BPH patients who had storage symptoms, the study said.