Cialis and Heart Conditions: How it Started
Cialis is meant to affect your cardiovascular system. When you get an erection, the arteries in your penis relax and open up, allowing more blood flow in. At the same time, the veins in that area close up. Once blood is in the penis, the pressure traps it within your corpora cavernosa (a.k.a. your erectile tissue). This is what makes your penis expand.
Cialis is a phosphodiesterase-5 (PDE5) inhibitor, and it works by preventing a particular enzyme found in blood vessel walls from working, thereby causing them to relax. Voila: your erection.
In fact, Cialis — and other well-known ED drugs like it — actually owe their existence to heart condition treatments. Scientists were investigating the effectiveness of PDE5 inhibitors in treating cardiovascular diseases, in particular angina, when they discovered men in clinical trials overwhelmingly reported increased erections as a side-effect. No one was thinking about ED, but the effectiveness as a treatment became impossible to ignore.
All this is to say that Cialis’ effect on your cardiovascular system is well-known — and that’s the point, as Cialis has to impact blood pressure to cause an erection. However, while Cialis and heart conditions have a history, they’re not always a great mix, as we’ll discover in the next section.
Cialis and Heart Medications
Cialis is safe for men with healthy hearts, but anyone with cardiovascular disease should take special precautions, and some men cannot use Cialis under any circumstances. This is because Cialis can amplify the effects of some medications for heart conditions.
Organic nitrates are widely used to treat heart conditions — predominantly Angina — to help lower blood pressure and widen blood vessels. They do this by increasing the supply of nitric oxide to arteries.
Nitric oxide activates guanylate cyclase, which helps convert guanosine triphosphate (GTP) into cyclic guanosine monophosphate (cGMP), which supports vasodilation. However, PDE5 inhibitors (like Cialis) interact with nitrates to create more cGMP. So if you mix heart medication consisting of nitrates with Cialis, your arteries will get a far stronger hit of cGMP, and you risk a significant drop in blood pressure.
Even healthy men given a mix of a PDE5 inhibitor with a nitrate medication saw their blood pressure drop by 25–51 mm Hg, a potentially dangerous amount. The possible effects of this are dizziness, fainting, heart attack, or a stroke.
Cialis stays active in your body for about two days after you’ve taken it, but longer if you have problems with your kidney or liver. Sometimes additional medications can make you metabolise Cialis more slowly, too. It’s therefore very important that you avoid taking nitrates and Cialis within 24–48 hours of each other.
It’s also very important that you tell your healthcare provider that you are taking Cialis, in case you ever need emergency medical care for a heart problem. If you believe you’re having acute heart problems, don’t waste time: contact a medical professional immediately.
Mixing Cialis and… Anything Else?
You should always avoid nitrates with Cialis, but you might not know if what you’re taking is a nitrate. After all, not all nitrates are used as heart medications. And is there anything else you should look out for?
Here’s a guide for what to avoid when taking Cialis:
- Poppers. Amyl nitrate or amyl nitrite, commonly known as poppers, are dangerous when mixed with Cialis.
- All preparations of nitroglycerin (including tablets or sprays).
- Long-acting nitrates (isosorbide dinitrate or Isordil, Sorbitrate, isosorbide mononitrate, Imdur, ISMO, and others).
- Alcohol. Combining this with Cialis can also lower your blood pressure.
- Large amounts of grapefruit juice. This decreases your gut’s ability to process Cialis.
- Men taking erythromycin, certain antifungal and anti-HIV medications should use Cialis in low doses.
- Men with significant kidney or liver disease should avoid larger doses of Cialis.
The Normal Side Effects
Cialis has some mild side effects. These usually go away by themselves within 48 hours. The most commonly reported are:
- Headache
- Flushing
- Muscle pain
- Back pain
- Indigestion
- Stuffy nose
- A small number of people also experience abnormal vision.
Below are the symptoms of a heart attack. They’re quite different. If you’re experiencing a mix of these, it’s time to call a medical professional:
- Chest pain — pressure, tightness or squeezing
- A sensation of pain travelling from your chest to one or both arms
- Pain in other parts of the body, such as jaw, neck, back or abdomen
- Feeling dizzy
- Sweating
- Shortness of breath
- Nausea or vomiting
- A sensation of extreme anxiety
- Coughing or wheezing
Can Cialis be Good for Your Heart?
All experts agree that men who are taking nitrates cannot use Cialis. But could Cialis and heart conditions ever be a good mix?
One study found that men prescribed a PDE5 inhibitor after their first heart attack were 38% less likely to die from any cause than those not taking any ED drugs. They were also 40% less likely to hospitalised for heart failure. However, this could simply indicate a more active sex life, which could contribute towards or indicate a healthier overall lifestyle.
Another study measured the effects of Cialis on sheep that were implanted with a pacemaker that mimicked the effect of heart failure. The hearts of sheep treated with Cialis retained the ability to pump blood, and the sheep displayed less of the breathing difficulties seen in the untreated animals. However, more research is needed into whether Cialis could help in treating humans with heart failure.
The Key Takeaways
Cialis widens your blood vessels, which is what allows more blood to flow to the penis and cause an erection. However, wider blood vessels mean a drop in blood pressure. This is perfectly safe for most men, but if you take Cialis in combination with other drugs that lower blood pressure, it could drop too low.
There’s some evidence that Cialis could help treat heart conditions — but not enough to be confident. It’s therefore very important that anyone who has suffered heart attacks, stroke, or serious cardiovascular disturbances in the last six months, has low blood pressure, or uncontrolled high blood pressure approaches Cialis with extreme caution.
If your heart’s healthy, however, Cialis is a safe, effective and proven way to treat erectile dysfunction.
¹Phauk.org- What are phosphodiesterase 5 inhibitors? – https://www.phauk.org/treatment-for-pulmonary-hypertension/oral-therapies/phosphodiesterase-5-inhibitors/
²Ian H. Osterloh. The discovery and development of Viagra® (sildenafil citrate): https://link.springer.com/chapter/10.1007/978-3-0348-7945-3_1
³Dr. Biji Soman, Prof. Govindan Vijayaraghavan. The role of organic nitrates in the optimal medical management of angina (2017). https://www.escardio.org/Journals/E-Journal-of-Cardiology-Practice/Volume-15/The-role-of-organic-nitrates-in-the-optimal-medical-management-of-angina
⁴BHF.org.uk – Angina medication: Questions about nitrates answered – https://www.bhf.org.uk/informationsupport/heart-matters-magazine/medical/drug-cabinet/nitrates
⁵www.ebmconsult.com – How does Nitroglycerin Interact with Type 5 Phosphodiesterase Inhibitors (PDE5; Avanafil, Sildenafil, Tadalafil, Vardenafil) to Cause Hypotension? – https://www.ebmconsult.com/articles/nitrates-ntg-pde-inhibitors-drug-interaction-mechanism-blood-pressure
⁶drugs.com – Cialis: 7 things you should know – https://www.drugs.com/tips/cialis-patient-tips
⁷drugs.com – Cialis (tadalafil) and Alcohol/Food Interactions – https://www.drugs.com/food-interactions/tadalafil,cialis.html
⁸Drugs.com – Drug Interactions between Cialis and grapefruit – https://www.drugs.com/drug-interactions/cialis-with-grapefruit-2144-1395-2624-0.html
⁹NHS.com – Symptoms–Heart attack – https://www.nhs.uk/conditions/heart-attack/symptoms/
¹⁰American College of Cardiology Foundation – Erectile Dysfunction Drugs Are Safe, Possibly Beneficial After Heart Attack – https://www.acc.org/about-acc/press-releases/2017/03/09/14/25/erectile-dysfunction-drugs-are-safe-possibly-beneficial-after-heart-attack
While we've ensured that everything you read on the Health Centre is medically reviewed and approved, information presented here is not intended to be a substitute for professional medical advice, diagnosis, or treatment. It should never be relied upon for specific medical advice. If you have any questions or concerns, please talk to your doctor.
