Tadalafil

Indications

Tadalafil is used for: Erectile dysfunction, signs and symptoms of benign prostatic hyperplasia (BPH)

Adult Dose

Oral Erectile dysfunction Adult: For Use as Needed The recommended starting dose of Tadalafil for use as needed in most patients is 10 mg, taken prior to anticipated sexual activity. The dose may be increased to 20 mg or decreased to 5 mg, based on individual efficacy and tolerability. The maximum recommended dosing frequency is once per day in most patients. For Once Daily Use The recommended starting dose of Tadalafil for once daily use is 2.5 mg, taken at approximately the same time every day, without regard to timing of sexual activity. The IntimateTM dose for once daily use may be increased to 5 mg, based on individual efficacy and tolerability. Benign Prostatic Hyperplasia Treatment of signs and symptoms of benign prostatic hyperplasia (BPH); daily use also indicated for treatment of patients with both BPH and erectile dysfunction BPH: 5 mg PO once daily BPH with erectile dysfunction: 5 mg PO once daily, taken at approximately same time each day without regard to timing of sexual activity With finasteride for BPH: tadalafil 5 mg plus finasteride 5 mg PO once daily for <26 weeks Pulmonary Arterial Hypertension 40 mg PO once daily; dividing dose for more frequent dosing is not recommended Patients also taking ritonavir: 20 mg PO once daily initially for >1 week; may be increased to 40 mg/day on basis of tolerability Hepatic impairment (erectile dysfunction) Mild-to-moderate (Child-Pugh class A or B): Not to exceed 10 mg PO once daily Severe (Child-Pugh class C): Not recommended Hepatic impairment (pulmonary arterial hypertension) Mild-to-moderate (Child-Pugh class A or B): Consider starting dosage of 20 mg PO once daily Severe (Child-Pugh class C): Avoid use

Child Dose

Renal Dose

Renal impairment (erectile dysfunction) Mild (CrCl >51 mL/min): No dosage adjustment needed Moderate (CrCl 30-50 mL/min): Not to exceed 5 mg PO once daily initially; maximum dosage, 10 mg PO q48hr Severe (CrCl <30 mL/min and on hemodialysis): Not to exceed 5 mg PO q72hr Renal impairment (pulmonary arterial hypertension) Mild-to-moderate (CrCl 31-80 mL/min): 20 mg PO once daily initially; may be increased to 40 mg once daily on basis of tolerability Severe (CrCl <30 mL/min and on hemodialysis): Avoid use

Administration

May be taken with or without food. In order for Tadalafil to be effective, sexual stimulation is required. It can be taken from 30 minutes to 12 hours prior to sexual activity. Efficacy of Tadalafil may persist up to 24 hours post-dose.

Contra Indications

Concurrent use of organic nitrates, nitrates and nitric oxide donors. Men with cardiac disease for whom sexual activity is inadvisable. Recent MI (within 90 days) or stroke (within last 6 mth), hypotension (<90/50 mm Hg), unstable angina, heart failure, uncontrolled arrhythmias or hypertension.

Precautions

Use caution in patients with anatomic deformation of penis, cardiovascular disease, left ventricular outflow obstruction, myocardial infarction in preceding 90 days, unstable angina, angina occurring during sexual intercourse, NYHA class 2 or greater heart failure in preceding 6 months, uncontrolled arrhythmias, hypotension, uncontrolled hypertension, cerebrovascular accident in preceding 6 months, bleeding disorders, active peptic ulcer disease, liver disease, renal impairment, conditions predisposing to priapism, concomitant use of CYP3A4 inhibitors Hepatic or renal impairment; CV diseases; anatomical penile deformation; predisposition to priapism; child <18 yr. Discontinue and seek medical advice if there is sudden vision loss or decreased vision in one or both eyes or tinnitus, dizziness or sudden loss or decrease in hearing, while taking Tadalafil. Seek immediate medical advice if erection last > 4 hr.

Pregnancy-Lactation

Interactions

Concurrent use increased risk of hypotension with beta-blockers; increased risk of priapism with other drugs for erectile dysfunction, e.g. alprostadil; increased heart rate with theophylline; decreased tadalafil serum concentration with CYP 3A4 inducers e.g. rifampicin, efavirenz, carbamazepine, nevirapine, barbiturates, phenobarbital, phenytoin, ribabutin; increased tadalafil serum concentration with CYP3A4 inhibitors e.g. azole antifungals, protease inhibitors, cimetidine, macrolides. Potentially Fatal: Enhanced hypotensive effect with nitrates and nicorandil.

Adverse Effects

Side effects of Tadalafil : >10% Headache (11-42%),Myalgia (1-14%),Respiratory tract infection (3-13%),Nasopharyngitis (2-13%),Dyspepsia (1-13%),Flushing (1-13%),Back pain (2-12%),Nausea (10-11%) 1-10% Nasal congestion (<9%),Gastroesophageal reflux disease (1-3%),Hypertension (1-3%),Bronchitis (<2%),Genitourinary tract infection (<2%) <1% Amnesia,Angina pectoris,Arthralgia,Change in color vision,Conjunctival hyperemia,Dyspnea,Epistaxis Potentially Fatal: Stevens-Johnson syndrome, exfoliative dermatitis, severe cardiovascular events e.g. MI, stroke, sudden cardiac death;

Mechanism of Action

Tadalafil is a phosphodiesterase type-5 inhibitor.