Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug are: riociguat, vericiguat.

Tadalafil can cause a serious drop in your blood pressure when used with nitrates, which can lead to dizziness, fainting, and rarely heart attack or stroke. Do not use any of the following with tadalafil or within 48 hours of your last dose of tadalafil: certain drugs used to treat chest pain/angina (nitrates such as nitroglycerin, isosorbide), recreational drugs called "poppers" containing amyl or butyl nitrite.

If you are also taking an alpha blocker medication (such as doxazosin, tamsulosin) to treat an enlarged prostate/BPH or high blood pressure, your blood pressure may get too low which can lead to dizziness or fainting. Your doctor may start treatment with a lower dose of tadalafil or adjust your alpha blocker medication to minimize your risk of low blood pressure.

Other medications can affect the removal of tadalafil from your body, which may affect how tadalafil works. Examples include azole antifungals (such as itraconazole, ketoconazole), macrolide antibiotics (such as clarithromycin, erythromycin), HIV protease inhibitors (such as fosamprenavir), rifampin, ritonavir, among others.

Do not take this medication with any other product that contains tadalafil or other similar medications used to treat erectile dysfunction-ED or pulmonary hypertension (such as sildenafil, vardenafil).