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.
A product that may interact with this drug is:
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 tadalafil with any of the following:
- 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, ritonavir), hepatitis C virus protease inhibitors (such as boceprevir, telaprevir), rifampin, 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).
Tadalafil may interact with other medications
Tadalafil oral tablet can interact with other medications, vitamins, or herbs you may be taking. An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well.
To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking. To find out how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.
Examples of drugs that can cause interactions with tadalafil are listed below.
Angina drugs (nitrates)
If you take tadalafil with nitrates, your blood pressure could suddenly drop to dangerously low levels. This could make you dizzy or cause you to faint. Examples of nitrates include:
- nitroglycerin
- isosorbide dinitrate
- isosorbide mononitrate
- amyl nitrite
- butyl nitrite
High blood pressure or prostate drugs (alpha blockers)
If you take tadalafil with certain alpha blockers, your blood pressure could suddenly drop to low levels that are dangerous. This could make you dizzy or cause you to faint. Examples of these drugs include:
- terazosin
- tamsulosin
- doxazosin
- prazosin
- alfuzosin
Certain HIV drugs
Taking tadalafil with certain HIV drugs could increase tadalafil levels in your blood. This can lead to low blood pressure, dizziness and fainting, and vision problems. In men, it can also lead to priapism. These drugs are protease inhibitors and include:
- ritonavir
- lopinavir/ritonavir
Oral antifungal drugs
Taking certain antifungal drugs with tadalafil may increase levels of tadalafil in your blood. This can lead to low blood pressure, dizziness and fainting, and vision problems. In men, it can also lead to priapism. Examples of these drugs include:
- ketoconazole
- itraconazole
Antibiotics
Taking certain antibiotics with tadalafil may raise the level of tadalafil in your blood. This can lead to low blood pressure, dizziness and fainting, and vision problems. In men, it can also lead to priapism. Examples of these drugs include:
- clarithromycin
- erythromycin
- telithromycin
Other types of antibiotics may lower the level of tadalafil in your blood. This could prevent tadalafil from working well. These drugs include:
Other erectile dysfunction (ED) drugs
These medications work in the same way as tadalafil. If you take them with tadalafil, it increases your risk of side effects. Examples of these drugs include:
Other pulmonary arterial hypertension (PAH) drugs
If you take tadalafil with other types of PAH drugs, your blood pressure could suddenly drop to dangerously low levels. Examples of these drugs include:
Stomach acid drugs
Taking these medications with tadalafil may keep your body from absorbing tadalafil well. Examples of these drugs include:
- magnesium hydroxide/aluminum hydroxide
Epilepsy drugs
Taking certain anti-seizure drugs with tadalafil may lower the level of tadalafil in your blood. This could prevent tadalafil from working well. Examples of these drugs include:
- carbamazepine
- phenytoin
- phenobarbital
