Important Safety Information for Tadalafil

What is Tadalafil?

Tadalafil is a prescription medication belonging to a class of drugs called phosphodiesterase type 5 (PDE5) inhibitors. It is used to treat erectile dysfunction (ED) in men by increasing blood flow to the penis during sexual stimulation. Tadalafil is also used to treat benign prostatic hyperplasia (BPH) and pulmonary arterial hypertension under different brand names. Tadalafil does not cure ED or increase sexual desire—it helps achieve and maintain an erection when you are sexually aroused.

Critical Warning: Nitrate Interaction

Do not take tadalafil if you use any form of nitrate medication. The combination of tadalafil with nitrates can cause a sudden, severe, and potentially fatal drop in blood pressure.

Nitrate medications include:

• Nitroglycerin (Nitrostat, Nitrolingual, Nitro-Dur, others)
• Isosorbide dinitrate (Isordil, Dilatrate)
• Isosorbide mononitrate (Monoket, Imdur)
• Amyl nitrite or amyl nitrate ("poppers")

If you have taken tadalafil and need emergency cardiac care, inform medical personnel immediately so they can avoid administering nitrates.

Who Should Not Use Tadalafil?

Do not use tadalafil if you:

• Take any nitrate medications for chest pain or heart conditions
• Use recreational drugs called "poppers" containing amyl nitrite or amyl nitrate
• Take riociguat (Adempas) or other guanylate cyclase stimulators
• Are allergic to tadalafil or any ingredient in the medication
• Have been advised by a doctor to avoid sexual activity due to heart problems
• Have had a heart attack within the past 90 days
• Have unstable angina or angina that occurs during sexual activity
• Have uncontrolled high or low blood pressure
• Have had a stroke within the past 6 months
• Have severe liver disease
• Have end-stage kidney disease requiring dialysis
• Have retinitis pigmentosa (a rare inherited eye condition)

Warnings and Precautions

1. Cardiovascular RiskSexual activity puts strain on the heart. Tadalafil should not be used by men for whom sexual activity is inadvisable due to underlying cardiovascular conditions. Before starting tadalafil, your healthcare provider should evaluate your cardiovascular health. If you experience chest pain, dizziness, or nausea during sexual activity, stop and seek medical help immediately.

2. Sudden Vision Loss (NAION)A rare condition called non-arteritic anterior ischemic optic neuropathy (NAION) has been reported in men taking PDE5 inhibitors, including tadalafil. This can cause sudden, partial or complete vision loss in one or both eyes. Stop taking tadalafil and seek immediate medical attention if you experience sudden vision loss. You may be at increased risk if you have had NAION before, have certain eye conditions, or have risk factors like heart disease, diabetes, high blood pressure, high cholesterol, or smoking.

3. Sudden Hearing LossSudden decrease or loss of hearing, sometimes with ringing in the ears (tinnitus) or dizziness, has been reported with PDE5 inhibitors. If you experience sudden hearing problems, stop taking tadalafil and contact your healthcare provider immediately.

4. Priapism (Prolonged Erection)Tadalafil can cause a painful erection lasting more than 4 hours. This is a medical emergency. If not treated promptly, priapism can permanently damage the penis. Seek immediate medical care if you have an erection lasting more than 4 hours. You may be at higher risk if you have sickle cell anemia, multiple myeloma, leukemia, or Peyronie's disease.

5. Blood Pressure EffectsTadalafil can lower blood pressure. This effect is increased when combined with alpha-blockers (medications for prostate problems or high blood pressure). If you take alpha-blockers, your doctor may start you on a lower dose of tadalafil. Symptoms of low blood pressure include dizziness, lightheadedness, and fainting.

6. Alcohol InteractionDrinking excessive alcohol while taking tadalafil may increase the risk of headache, dizziness, low blood pressure, and rapid heartbeat. Limit alcohol consumption while using this medication.

Common Side Effects

The most frequently reported side effects include:

• Headache
• Indigestion or upset stomach
• Back pain
• Muscle aches
• Flushing (warmth or redness in the face, neck, or chest)
• Stuffy or runny nose
• Pain in arms or legs
• Dizziness
• Nausea

Back pain and muscle aches typically occur 12-24 hours after taking tadalafil and usually resolve within 48 hours.

Drug Interactions

Tell your healthcare provider about all medications you take, especially:

• Nitrates – Contraindicated; can cause dangerous blood pressure drop
• Alpha-blockers (tamsulosin, doxazosin, alfuzosin) – Increased risk of low blood pressure; dose adjustments may be needed
• Other PDE5 inhibitors (sildenafil, vardenafil, avanafil) – Do not combine
• Riociguat – Contraindicated
• HIV protease inhibitors (ritonavir, saquinavir) – May increase tadalafil levels; dose adjustment required
• Certain antifungal medications (ketoconazole, itraconazole) – May increase tadalafil levels
• Certain antibiotics (erythromycin, clarithromycin) – May increase tadalafil levels
• Blood pressure medications – May have additive blood pressure-lowering effects

Do not eat grapefruit or drink grapefruit juice while taking tadalafil, as it may increase medication levels in your blood.

Dosing Information

Tadalafil is available in different dosing options:

As-needed dosing: Take 10-20 mg at least 30 minutes before sexual activity. Do not take more than one dose in 24 hours.

Daily dosing: Take 2.5-5 mg at the same time each day, regardless of timing of sexual activity.

Your healthcare provider will determine which dosing approach is right for you based on your health conditions and other medications.

Special Populations

Kidney impairment: Dose adjustments may be necessary.

Liver impairment: Use with caution; dose adjustments may be needed.

Elderly patients: No dose adjustment required based on age alone, though elderly patients may be more sensitive to effects.

Storage

Store at room temperature between 59°F and 86°F (15°C to 30°C). Keep away from moisture and heat. Keep out of reach of children.

Important Reminders

• Tadalafil does not protect against sexually transmitted infections including HIV
• Tadalafil requires sexual stimulation to work—it does not cause automatic erections
• Do not share tadalafil with others, even if they have similar symptoms
• Inform all healthcare providers that you take tadalafil, especially before surgery or emergency care

When to Seek Emergency Medical Care

Get emergency help immediately if you experience:

• Chest pain during or after sexual activity
• Sudden vision loss in one or both eyes
• Sudden hearing loss or ringing in the ears
• An erection lasting more than 4 hours
• Signs of allergic reaction (rash, hives, swelling of face/lips/tongue/throat, difficulty breathing)
• Fainting or severe dizziness

Reporting Side Effects

Report side effects to the FDA at www.fda.gov/medwatch or call 1-800-FDA-1088.

This information is not comprehensive. Consult your healthcare provider for complete prescribing information about tadalafil.