About 20.1 million adults 20 years and older in the United States have coronary artery disease, and chest pain can be an unpleasant frequent reality for many of those people.

There are many different reasons for chest pain, but the type called angina is typically caused by narrowing blood vessels that supply blood to your heart. If you’re experiencing angina pain, there are medications available to help treat it. Isosorbide mononitrate is one such medication.

If a doctor or healthcare professional has recommended you take isosorbide mononitrate, this article can provide more information on how this medication works and what the potential side effects are.

Isosorbide is classified as a nitrate medication. It works by releasing nitric oxide, which causes your blood vessels to widen. This is also known as vasodilation.

There are two forms of isosorbide: mononitrate and dinitrate. Isosorbide mononitrate differs from isosorbide dinitrate in the way it’s metabolized by your liver. Isosorbide mononitrate doesn’t undergo a first pass of your liver and lasts many hours longer before it’s eliminated.

Isosorbide mononitrate relaxes your blood vessels and increases the supply of blood and oxygen to your heart. This helps to reduce your heart’s workload. But isosorbide mononitrate doesn’t cure coronary artery disease.

Isosorbide mononitrate can be found under a variety of brand names including Imdur, Monoket, and Ismo. This medication is available in immediate-release tablets as well as extended-release capsules.

Isosorbide mononitrate tablets are frequently prescribed to be taken two or three times daily, while the extended-release option may only be taken once a day. It’s important to follow a doctor’s prescription exactly. The pills should be taken whole and not crushed.

Isosorbide mononitrate is used to manage chest pain in people with coronary artery disease. It can also be used in combination with other medications to help treat heart failure.

Those who live with obesity and diabetes and who smoke are also at an increased risk of chest pain. But isosorbide mononitrate isn’t designed to treat these issues.

One thing to keep in mind is that this medication doesn’t work fast enough to help with a heart attack. It also isn’t designed to be taken right before physical activity to prevent chest pain. Other medications may be prescribed and used in these situations.

Isosorbide mononitrate can cause nausea, and you should notify a doctor if this becomes severe.

Headaches or dizziness may also occur. For some people, headaches may be severe or occur daily, but this can actually mean the isosorbide is working properly. It’s important not to stop taking isosorbide mononitrate as prescribed without discussing it with a doctor. Before taking any headache-relieving medications, you should also discuss potential implications with a doctor.

You should notify a doctor if you experience rashes, hives, or itching. You should call 911 or local emergency services if you experience worsening chest pains or difficulty breathing and swallowing.

Alcohol can make the side effects of isosorbide worse, so you may wish to refrain from drinking or limit your drinking while on this medication.

You shouldn’t take an erectile dysfunction medication such as Viagra while taking isosorbide mononitrate. Taking both together can cause a sudden, serious decrease in blood pressure.

It’s important to discuss any plans to discontinue your use of isosorbide mononitrate with a doctor, as stopping suddenly can result in a severe angina attack. (It’s a good idea to fill your prescription before you run out to prevent missing a dose.)

Isosorbide mononitrate may not work as well if you’ve taken it for a long time or if you’ve taken too many doses. To help prevent this, a doctor will plan your doses so that there’s a period of time during the day when you’re not exposed to the medication.

Isosorbide mononitrate is a generic medication prescribed for chest pain related to heart disease. It’s classified as a nitrate and can be found under many different brand names including Imdur, Monoket, and Ismo.

Isosorbide mononitrate isn’t an emergency rescue medication and shouldn’t be used to treat heart attacks. If you’re experiencing sudden, severe chest pain or showing other symptoms of a heart attack, call 911 or local emergency services immediately.