1. Treatment of erectile dysfunction
2. Benign prostatic hyperplasia

Tadalafil is a reversible, selective phosphodiesterase type 5 (PDE-5) inhibitor. It increased levels of c-GMP in the corpus cavernosum, resulting in smooth muscle relaxation and inflow of blood to the corpus cavernosum.

Onset: within1 hour
Time to peak: 2hr
Duration: Up to36 hrs
Protein binding: 94%
Metabolism: Hepatic via CYP3A4
Elimination half-life: 17.5 hr.

concomitant use of nitrates (any form) either regularly or intermittently, hypersensitivity to tadalafil, known serious; Stevens-Johnson syndrome and exfoliative dermatitis have been reported.

Headache, dyspepsia, flushing, CPK increased, myalgia, abnormal liver function tests, blurred vision, dizziness, fatigue, insomnia, postural hypotension, GTP increased.

Erectile dysfunction:
2.5 mg ORALLY once daily at the same time each day; may increase to 5 mg ORALLY once daily based on efficacy and tolerability.
Benign prostatic hyperplasia:
Initial 2.5 mg QD, may increase to 5 mg ORALLY once daily at the same time each day.
Concomitant strong CYP3A4 inhibitor use (eg, ketoconazole, itraconazole, ritonavir) (erectile dysfunction and/or BPH): once daily use, MAX 2.5 mg ORALLY once daily.
Concomitant alpha blocker use (BPH): avoid use.

Severe renal impairment: ClCr <30 ml/min or hemodialysis:
Erectile dysfunction、BPH : once daily use, not recommended.
Erectile dysfunction: as needed use, MAX dose is 5 mg ORALLY

Severe hepatic impairment (Child-Pugh Class C) (erectile dysfunction and/or BPH): not recommended.