What is the FDA-approved use of tadalafil? 

Tadalafil is a phosphodiesterase-5 (PDE5) inhibitor indicated for the treatment of erectile dysfunction (ED). 

Who should not use tadalafil? 

Do not use tadalafil if: 

• You are taking a class of medications called nitric oxide donors, including organic nitrates or organic nitrites in any form. Tadalafil can increase the blood pressure-lowering effect of nitrates. 
• You have a known allergy to tadalafil. 
• You are taking a class of medications called guanylate cyclase (GC) stimulators, such as riociguat. Tadalafil can increase the blood pressure-lowering effects of these medications. 

How should I take tadalafil? 

Tadalafil can be taken with or without food. Limit the amount of alcohol to <5 drinks. 

• As-needed use: Take about 30 minutes before anticipated sexual activity. 
• Daily use: Take once daily at about the same time every day, without regard to the timing of sexual activity. 

Do not take tadalafil more than once in a 24-hour period or within 24 hours of any other ED medications or PDE-5 inhibitors. 

You should take the medication exactly as prescribed. If your symptoms are not improving or you have any questions about changing or stopping medication, reach out to your Ro-affiliated provider for guidance. 

What should I tell my DPC-affiliated provider before using tadalafil? 

Tadalafil has certain drug interactions. It’s important to tell your DPC-affiliated provider all of the medications you are currently taking, including prescription, over-the-counter medications, vitamins, and herbal and dietary supplements.  

Some medications to watch out for include: 

• Nitrates, alpha-blockers, and antihypertensives: When these medications are taken with tadalafil, a sudden drop in blood pressure can occur. 
• CYP3A4 inhibitors, such as ritonavir, ketoconazole, itraconazole, and erythromycin: These medications increase tadalafil levels in the bloodstream, which can cause a sudden drop in blood pressure and prolonged erection. 
• Alcohol: Drinking large amounts of alcohol (>5 units) with tadalafil can increase the potential for a sudden drop in blood pressure. 

It’s important to share your entire medical history with your provider. In particular, tell your provider if you have or have a past history of: 

• Cardiovascular risk that prevents you from partaking in sexual activity 
• Chest pain requiring nitroglycerin 
• Predisposition to priapism (painful erection that lasts >4 hours) 
• Benign prostatic hyperplasia (BPH) and are being treated with alpha-blockers  
• Ventricular outflow obstruction (e.g. aortic stenosis, idiopathic hypertrophic subaortic stenosis) 
• Severely impaired autonomic control of blood pressure 
• Myocardial infarction, stroke, or life-threatening arrhythmia  
• Low or high blood pressure 
• Cardiac failure or coronary artery disease causing unstable angina 
• Anterior ischemic optic neuropathy (NAION) or a “crowded” optic disc. 
• Bleeding disorders or ulcers 
• Kidney or liver disease 
• Pulmonary hypertension 
• Retinitis pigmentosa 

Withholding or providing inaccurate information about your health and medical history in order to obtain treatment may result in harm, including, in some cases, death. 

What are the most serious side effects that I or a caregiver should monitor for when taking tadalafil? 

If you are experiencing a medical emergency, call 911 or seek immediate medical attention. 

You or a caregiver should carefully monitor for these side effects, especially at the beginning of treatment. 

• Cardiac risk of sexual activity: ED medication should not be used by men for whom sexual activity is not advised because of their underlying cardiovascular status.  
• Prolonged erections: Seek immediate emergency treatment for an erection lasting more than 4 hours. 
• Effects on the eye: Seek medical care and stop medication if you experience a sudden loss of vision in one or both eyes. Sudden loss of vision could be a sign of non-arteritic anterior ischemic optic neuropathy (NAION). 
• Sudden hearing loss: Stop medication and seek prompt medical attention if you experience a sudden decrease or loss of hearing, which may be accompanied by ringing in the ears.   
• Co-administering with alpha-blockers or other blood pressure-lowering drugs: If you are taking a medication to lower your blood pressure or taking an alpha-blocker, tadalafil may increase the blood-pressure-lowering effect, leading to a sudden drop in blood pressure. When starting tadalafil, monitor carefully for signs of low blood pressure, including dizziness, light headedness, or fainting. 
• Kidney impairment: Talk to your DPC -affiliated provider about the appropriate dose of tadalafil if you have kidney impairment.  
• Liver impairment: Talk to your DPC-affiliated provider about the appropriate dose of tadalafil if you have liver impairment.  
• Alcohol: Drinking large amounts of alcohol (>5 units) with tadalafil can increase the potential for a sudden drop in blood pressure. 
• Co-administering with CYP3A4 inhibitors: Talk to your DPC-affiliated provider about the appropriate dose of tadalafil if you are taking potent inhibitors of CYP3A such as ritonavir, ketoconazole, and itraconazole. 
• Combination with other PDE-5 inhibitors: Do not take tadalafil more than once in a 24-hour period or within 24 hours of any other ED medications or PDE-5 inhibitors. 
• Effects on bleeding: Tadalafil did not affect bleeding time when taken alone or with aspirin. Tell your DPC-affiliated provider if you have a bleeding disorder or ulcers. 
• Sexually transmitted infections: Tadalafil does not protect against sexually transmitted diseases. Use safe sex practices. 

What are the most common side effects of tadalafil? 

• Headache 
• Indigestion 
• Back pain 
• Muscle pain 
• Nasal congestion 

• Flushing 
• Pain in limb 

You are encouraged to report negative side effects of prescription products to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088.