Dual antiplatelet therapy (DAPT) combines medications used to treat conditions associated with blood clotting like a heart attack or stroke. These medications can also help prevent complications from other conditions or procedures, but they have a few risks.

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Dual antiplatelet therapy (DAPT) combines medications designed to thin your blood and prevent clotting. DAPT is usually used to treat or prevent problems associated with heart attacks or certain kinds of strokes.

DAPT aims to thin your blood if you have certain implants or another condition that makes developing a blood clot in the wrong place particularly dangerous.

Aspirin is the most common choice, and DAPT is usually a combination of low dose aspirin, (between 75 and 100 mg, typically 81 mg) combined with another medication. Over-the-counter (OTC) aspirin tends to be sold at 325 mg strength for pain relief.

One of the most common uses for DAPT is to prevent the formation of clots after the implantation of stents.

People who’ve had a stent installed

Stents are tiny tubes placed inside the vessels that supply blood to your heart. People who need stents have narrowing or blockages in their blood vessels that could stop the blood supply to the heart, causing a heart attack.

When foreign objects of any kind are implanted into your body, there’s a risk that your body will try to coat or cover that device somehow.

Platelets are a type of sticky cell in your blood that forms clots to help close wounds and stop bleeding when you get hurt. While platelets serve an important function on their own, they can cause serious problems in certain situations. In the case of stent placement, platelets can build up on stents, creating the same type of blockages they were implanted to prevent.

People who’ve had a heart attack

These medications help treat or prevent heart attacks even if you don’t have a stent, especially if you’re at risk of developing blood clots that could travel to the vessels that supply your heart.

People who’ve had a stroke

DAPT is also used to treat or prevent certain types of strokes. Strokes caused by blood clots are usually treated with blood-thinning medications, but the leading risk factor for a stroke is having already had one. A doctor may prescribe ongoing antiplatelet therapy to help prevent the formation of additional blood clots that could develop into strokes.

What do antiplatelet medications treat?

To understand why you might need DAPT, it can help to know the uses of antiplatelet medications.

Some conditions treated with antiplatelet medications include:

Using a single antiplatelet medication with any of these conditions is possible, but there’s also a chance a doctor could add a second medication to your regimen.

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Using DAPT may pose a risk for some people. Injuries, falls, or bleeding disorders may be more dangerous if you take DAPT.

A healthcare professional will evaluate your need for DAPT on a case-by-case basis, considering both your medical needs and your individual risk factors.

Some reasons not to take DAPT include:

If you’re high risk, a doctor may want you to take DAPT for a shorter period of time.

Antiplatelet medications fall into a few categories based on how they work inside the body. The common goal of any of these medications is to prevent platelets from sticking to themselves or other things.

By preventing platelets from sticking together, or aggregating, clots are not formed. Preventing platelets from sticking to other things, like stents or implants, may also prevent blood clot formation.

There are several categories of antiplatelet medications. Each prevents platelets from sticking together. DAPT often includes aspirin and other medications. Medications you may see prescribed alongside aspirin as a part of DAPT include:

The main benefit of DAPT is that it prevents blood clots from forming by preventing platelets from sticking to each other or other things. Blood clots can cause problems in most body areas, but they are especially dangerous when they develop in the brain, heart, or lungs.

Since antiplatelet medications used in DAPT work by preventing platelets from clumping together, people who take these medications run the risk of having bleeding that’s difficult to control. A small cut may bleed more than usual, and larger injuries or conditions like a hemorrhagic stroke could be catastrophic.

Drug interactions

Because there may be a number of specific drug interactions for antiplatelet medication, your doctor will likely advise you to avoid medications that may increase your risk of bleeding. This includes things like nonsteroidal anti-inflammatory drugs (NSAIDs).

A study from 2013 suggests that there may also be a risk from taking certain OTC proton pump inhibitors (PPI), such as the antacids Nexium or Prilosec OTC. However, more research is needed.

Talk with a doctor about any prescription or OTC medications you’re taking or may start taking to be sure there’s no possible interaction with your DAPT.


Everyone’s body responds to medications in different ways. Even if you’re taking DAPT as prescribed, if you have a stronger response, the effects could become more potent in your body.

It’s also possible to accidentally overdose on DAPT, especially if you take several medications daily. Reports from national poison centers revealed that in 2018, there were more than 300 overdoses reported for antiplatelet medications, with 16 cases involving severe hemorrhage and two resulting in death.

Other interactions

In addition to certain medications, there are foods and supplements you may need to avoid on DAPT.

Avoid eating grapefruit when taking DAPT, and talk with a doctor about any nutritional or herbal supplements you take or before you start taking them.

Bleeding is the main side effect and complication associated with antiplatelet medications. This bleeding can take several forms:

  • nosebleeds
  • gastrointestinal bleeding
  • intracranial hemorrhage
  • retroperitoneal bleeding

Talk with the doctor who prescribed your DAPT immediately if you have:

  • concerns you may be having excessive bleeding
  • symptoms of a stroke
  • vomit or stools that are maroon or resemble coffee grounds.

There may be other things to avoid during antiplatelet therapy. You may also want to consider your activities and daily habits.

If you’re prone to falls, take extra precautions while using antiplatelet medications. You may also want to avoid contact or competitive sports that could increase your risk of injury. Even shaving can present risks to people on antiplatelet medications.

When to seek emergency care

If you develop sudden heavy bleeding, seek emergency medical care immediately.

A hemorrhagic stroke — or bleeding in your brain — can appear with weakness on one side of your body, slurred speech, and confusion, among other symptoms.

A gastrointestinal bleed could cause your vomit to resemble coffee grounds or turn your bowel movements a purple or maroon color.

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How long do I have to take DAPT?

The length of time you need DAPT will depend on many factors, such as your specific health, bleeding risk, and medical conditions. The time you need DAPT can vary from 1 month to several years. Some people may need DAPT indefinitely. Talk with a doctor about how long you can expect to be on DAPT.

What happens if I stop taking DAPT?

Never stop taking prescription medications without talking with a doctor first. If you’re on DAPT, you risk developing blood clots, so stopping the medication could result in the formation of a serious — even fatal — blood clot.

Do you need a prescription for DAPT?

DAPT medications are available only by prescription. While aspirin is available as an OTC medication and is usually a part of DAPT, talk with your doctor before starting to take aspirin on a regular basis.

Can DAPT be reversed?

Some antidotes can reverse DAPT medications, but these vary depending on the specific medication. If you experience heavy bleeding during DAPT, you may also be given other treatments, such as vitamin K or an infusion of donated platelets.

DAPT is a specialized treatment that may be used if you are at high risk of developing dangerous blood clots.

You may need DAPT a cardiac catheterization procedure in which you get a stent. You may also need DAPT to help prevent and treat certain types of strokes.

Talk with a doctor about your specific risk factors and other things you need to know about the specific DAPT combination you’re prescribed.