Important Safety Information — Tadalafil

Indications

Tadalafil is a phosphodiesterase type 5 (PDE5) inhibitor indicated for the treatment of erectile dysfunction (ED). Tadalafil has a longer duration of action (up to 36 hours) compared to other PDE5 inhibitors, allowing for more flexibility in timing of sexual activity.

Contraindications

• Nitrates: Administration to patients using any form of organic nitrates is contraindicated. Tadalafil potentiates the hypotensive effect of nitrates, which can result in a severe and potentially fatal drop in blood pressure.
• Guanylate cyclase (GC) stimulators: Concomitant use with soluble GC stimulators (e.g., riociguat) is contraindicated due to risk of hypotension.
• Known serious hypersensitivity to tadalafil or any component of the formulation (e.g., angioedema, Stevens-Johnson syndrome, exfoliative dermatitis)

Warnings and Precautions

• Cardiovascular risk: Serious cardiovascular events, including myocardial infarction, sudden cardiac death, stroke, chest pain, palpitations, and tachycardia, have been reported in temporal association with tadalafil use. Most, but not all, of these patients had preexisting cardiovascular risk factors.
• Hypotension: Tadalafil has vasodilatory properties resulting in mild, transient decreases in blood pressure. Ensure patients are hemodynamically stable before prescribing.
• Priapism: Prolonged erections greater than 4 hours and priapism (painful erections greater than 6 hours) have been reported rarely. Seek immediate medical attention if an erection lasts longer than 4 hours.
• Vision loss (NAION): Non-arteritic anterior ischemic optic neuropathy (NAION) has been reported rarely. Discontinue and seek immediate medical attention if sudden vision loss occurs.
• Sudden hearing loss: Sudden decrease or loss of hearing, sometimes with tinnitus and dizziness, has been reported. Stop tadalafil and seek medical attention immediately.
• Alpha-blockers: When used in combination, additive effects on blood pressure may be anticipated. Patients should be stable on alpha-blocker therapy prior to initiating tadalafil at the lowest recommended dose.
• Renal impairment: Dose adjustments may be needed for patients with creatinine clearance less than 30 mL/min or on hemodialysis.
• Hepatic impairment: Exposure is increased in patients with hepatic impairment. Dose limitation recommended.

Common Side Effects

• Headache
• Dyspepsia (indigestion)
• Back pain
• Myalgia (muscle pain)
• Nasal congestion
• Flushing
• Pain in limbs

Serious Side Effects

Seek medical attention immediately if you experience any of the following:

• An erection lasting longer than 4 hours (priapism)
• Sudden loss of vision in one or both eyes
• Sudden decrease or loss of hearing, with or without ringing in the ears or dizziness
• Chest pain, dizziness, or nausea during sexual activity
• Severe hypotension (lightheadedness, fainting)
• Signs of a serious allergic reaction (rash, hives, swelling of face/lips/tongue/throat, difficulty breathing)
• Seizures

Drug Interactions

• Nitrates: Absolutely contraindicated. Potentiates hypotensive effects with risk of cardiovascular collapse.
• GC stimulators (riociguat): Contraindicated due to additive hypotensive effects.
• Alpha-blockers: Both are vasodilators with blood-pressure-lowering effects. Additive effect on blood pressure may be anticipated.
• CYP3A4 inhibitors (e.g., ketoconazole, ritonavir, itraconazole): Increase tadalafil exposure. Maximum recommended dose is 10 mg every 72 hours for potent inhibitors.
• CYP3A4 inducers (e.g., rifampin, carbamazepine, phenytoin, phenobarbital): May decrease tadalafil exposure and effectiveness.
• Antihypertensives: Additional blood pressure reduction is possible. Monitor blood pressure.
• Alcohol: Substantial consumption (5 or more units) can increase risk of orthostatic signs and symptoms including increased heart rate and decreased standing blood pressure.
• Other PDE5 inhibitors: Do not use with sildenafil, vardenafil, or avanafil.

Use in Specific Populations

• Pregnancy: Tadalafil for ED is not indicated for use in women.
• Pediatric use: Not indicated for use in pediatric patients.
• Geriatric use: No dose adjustment required solely based on age, but consider the greater frequency of comorbidities in elderly patients.
• Hepatic impairment: For mild-to-moderate impairment (Child-Pugh Class A or B), dose should not exceed 10 mg. Not recommended for severe hepatic impairment.
• Renal impairment: For creatinine clearance 30-50 mL/min, a starting dose of 5 mg is recommended, with max of 10 mg not more than once every 48 hours. For clearance less than 30 mL/min or on hemodialysis, max dose is 5 mg.