Tadalafil (Cialis), currently marketed for erectile dysfunction, also may be used to treat benign prostatic hyperplasia (BPH), the FDA said.
The newly approved indication includes both prostate enlargement by itself and when it occurs along with erectile dysfunction.
Two clinical trials demonstrated the drug's effectiveness in BPH, the agency said. Men who took 5 mg of tadalafil once daily showed a significant reduction in total International Prostate Symptom Score.
In a third study of men with concomitant erectile dysfunction and prostate enlargement, the 5-mg/day dose improved symptoms of both conditions, according to the FDA.
Tadalafil is the first phosphodiesterase-5 inhibitor to be approved for BPH. Eight other drugs are currently available for the condition, all of which are either alpha-adrenergic blockers or 5-alpha-reductase inhibitors.
As with other drugs in its class, tadalafil should be avoided in patients taking nitrates. Combining tadalafil with alpha blockers also is not recommended because such pairings have not been evaluated adequately and hypotension could result, the FDA indicated.
For erectile dysfunction, tadalafil's recommended initial dosing is 10 mg when used intermittently prior to anticipated sexual activity, and 2.5 mg/day when taken on a daily basis. The maximum daily dose for erectile dysfunction is 5 mg/day.