Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 2/8/2022
Erectile dysfunction (ED) is one of the most common forms of sexual dysfunction in men, with an estimated 30 million men affected in the United States.
If you have ED, you might find it difficult to get an erection at all, or maintain an erection that’s firm enough to have penetrative sex.
Erectile dysfunction is treatable with medication. ED medications such as sildenafil (the active ingredient in Viagra®), tadalafil (Cialis®) and others have been around for more than a decade, with millions of users and proven safety records.
For most healthy men without cardiovascular health conditions, ED medications are thoroughly tested and viewed as safe to use.
However, if you have cardiovascular disease, hypertension or other heart health issues, it may not be safe to use ED medication.
Below, we’ve explained how ED medications like sildenafil work, as well as their effects on the cardiovascular system.
We’ve also explained what you can do to treat erectile dysfunction if you have a cardiovascular health issue, or if you’ve previously suffered from a heart attack or other cardiovascular event.
Most erectile dysfunction medications belong to a class of drugs called PDE5 inhibitors. They work by inhibiting the enzyme phosphodiesterase-5, which is responsible for controlling blood flow to the erectile tissue inside your penis.
Erections are all about blood flow. When you’re sexually aroused, blood begins to flow to your penis, creating a firm, enlarged erection that allows you to have sex.
By inhibiting PDE5, ED medications make it easier for blood to flow to your penis, allowing you to get hard and stay hard during sex.
Most ED medications start working quickly and produce a noticeable change in sexual function within one hour.
One common misconception is that ED medications make your penis hard all the time, even if you aren’t sexually aroused.
This isn’t accurate. While ED medications do make it easier to get an erection when you feel in the mood for sex, they don’t have any known effect on the psychological side of sexual arousal and won’t cause you to get an erection if you aren’t sexually stimulated.
Are Viagra and other ED medications bad for your heart? Luckily, most ED medications are safe for men with heart disease. However, there are some issues that you should know about before using these medications if you have heart disease, hypertension or another cardiovascular health issue.
By targeting PDE5, ED medications dilate the blood vessels that supply blood to your penis and make it easier to get and maintain an erection.
However, they can also cause blood vessels in other parts of your body to dilate. For example, a similar effect can occur in your lungs, where the pulmonary arteries -- the blood vessels that are responsible for transporting blood from the heart to the lung capillaries -- also dilate.
This increase in blood vessel diameter can cause a reduction in blood pressure. For this reason, some PDE5 inhibitors are used to treat pulmonary hypertension -- a form of high blood pressure that affects the blood vessels in the lungs.
So, how does this affect your heart health? Although PDE5 inhibitors are safe for most men with heart disease, when they’re used with medications called nitrates, they can cause a severe drop in blood pressure that may be dangerous.
Nitrates are commonly prescribed to lower blood pressure and reduce stress on the heart. Your healthcare provider may prescribe a nitrate if you have hypertension (high blood pressure), or if you have reduced blood flow caused by coronary heart disease.
Most ED medications also affect the cardiovascular system through an increase in nitric oxide production.
Nitric oxide is a signaling molecule released by arteries to dilate blood vessels. ED medications work by increasing the body’s production of nitric oxide, which boosts blood flow to areas of the body like the soft tissue of the penis.
Nitrates and related medications that can interact with ED drugs include nitroglycerin, isosorbide dinitrate and isosorbide mononitrate.
Other medications that can interact with ED drugs include alpha-blockers and non-nitrate drugs used to control high blood pressure. Some recreational “poppers,” also contain nitrates such as amyl nitrite or amyl nitrate, which can also interact with ED medications.
To put this potential drop in blood pressure into perspective, consider that most ED medications cause a temporary reduction in blood pressure of around 5 to 8 mmHg. This decrease occurs in all men, including those without heart disease.
When the ED medication Viagra is combined with nitroglycerin, this decrease in blood pressure grows to 25 to 51 mmHg -- an amount that can be dangerous.
In short, if you use nitrates to treat angina, high blood pressure or other heart health issues, you cannot and should not take ED medication.
If you suffer from heart disease and erectile dysfunction and wish to learn more about treatment options, you should speak to your healthcare provider about safe treatments.
Even if you don’t use nitrates, you should be extremely cautious about taking ED medication if you’re affected by heart disease.
The FDA recommends caution in men who’ve suffered from cardiovascular events in the past six months. These include myocardial infarction (heart attack), stroke and other disturbances of the heart’s rhythm and function.
Caution is also recommended for men with uncontrolled hypertension, men with clinically low blood pressure, and men with a history of congestive heart disease and/or angina.
Many of these conditions are quite common. For example, almost 37 million American adults have uncontrolled hypertension with a blood pressure of 140/90 mmHg or higher.
If you have any of these conditions, or if you have concerns about your heart function, it’s best to talk to your healthcare provider about your safety before considering using any medications for ED.
Your healthcare provider will be able to assess your cardiovascular function and, if appropriate, prescribe a medication that’s suitable for you. If ED medication isn’t appropriate, they may also be able to suggest an alternative treatment.
If you’ve had a heart attack, it’s important to talk to your healthcare provider before you use any type of medication to treat ED, including oral PDE5 inhibitors.
Most of the time, you should be able to resume your usual sex life after successfully recovering from a heart attack. If your healthcare provider allows it, all ED medications, including sildenafil, tadalafil, vardenafil and avanafil, should be safe to use as prescribed.
Interestingly, some research suggests that using ED medication after a heart attack may reduce your risk of being hospitalized for heart failure in the future.
There’s no “best” ED medication for use after a heart attack. As always, it’s important to talk to your healthcare provider and work out the most appropriate medication for you based on your needs, lifestyle and expectations.
While oral medications like sildenafil may be the most well-known form of treatment for erectile dysfunction, they’re not the only options available.
Other options for treating ED include injectable medication and psychotherapy for issues such as psychological erectile dysfunction. Certain lifestyle changes, such as quitting smoking, can also improve your erectile function naturally.
In addition to oral PDE5 inhibitors, other medications are available to treat ED. One medication that’s often used is alprostadil -- an injectable medication that works by relaxing the local blood vessels and muscle tissue inside the penis.
Alprostadil is also available as a suppository, which is inserted into the urethra. Your healthcare provider may prescribe alprostadil if other ED medications aren’t suitable for you to use or don’t produce the intended effects.
Although lifestyle changes alone aren’t always enough to treat severe ED, changing your habits can often strengthen your erections and improve your sexual performance. Try the following tips and lifestyle changes for better erections and sexual performance:
Quit cigarette smoking
Limit your alcohol intake or stop drinking alcohol
Avoid using illicit drugs
Get regular physical activity and exercise
Maintain a healthy body weight
Our list of natural ways to protect your erection goes into more detail about how you can reduce the severity of ED naturally.
Many cases of ED are psychological, meaning they’re caused primarily by mental or emotional issues rather than physical ones.
If your erectile dysfunction has a psychological cause, you may benefit from counseling to work on anxiety, stress or depression. You can talk to a counselor locally or online using our mental health services.
Erectile dysfunction can have a serious impact on both your sexual function and your quality of life. Luckily, even if you have heart disease or specific cardiovascular risk factors, ED is almost always a treatable condition.
If you’re affected by erectile dysfunction, it’s best to talk to your healthcare provider about your options. You can also access our full range of FDA-approved ED treatments online, following a private online consultation with a licensed healthcare provider.
Worried your physical health may be contributing to ED? Our guide to the most common causes of erectile dysfunction explains how ED usually develops, as well as the steps that you can take to improve your erections and sexual health.