Ticagrelor is a prescription oral medication sold under the brand name Brilinta. It is classified as an antiplatelet agent, a type of drug sometimes referred to as a blood thinner. This medication prevents platelets, a type of blood cell involved in clotting, from grouping together to form unwanted blood clots.
Medical Uses of Ticagrelor
Doctors prescribe ticagrelor primarily to lower the risk of stroke, heart attack, or other serious cardiovascular problems in people with a history of these events. It is frequently used for patients with acute coronary syndrome (ACS), a term for situations where blood supply to the heart muscle is suddenly blocked. ACS includes recent heart attacks or unstable angina, which is chest pain caused by reduced blood flow to the heart.
The medication also prevents blood clots in patients with stents in their heart arteries. A stent is a small mesh tube that holds an artery open, and ticagrelor helps maintain blood flow through it. Additionally, it may be prescribed for individuals with coronary artery disease (CAD) who are at a high risk of having a first heart attack or stroke. In cases of acute ischemic stroke or a high-risk transient ischemic attack (TIA), often called a mini-stroke, ticagrelor can be used to reduce the chance of a subsequent stroke.
How Ticagrelor Works
When a blood vessel is injured, platelets normally stick together to form a clot and stop bleeding. However, these clots can sometimes form inside arteries, blocking blood flow to the heart or brain. Platelets are activated to clump together by a substance called adenosine diphosphate (ADP).
Ticagrelor blocks a specific receptor on the surface of platelets called the P2Y12 receptor. It binds to this receptor, preventing ADP from attaching to it and signaling for platelets to aggregate. Unlike some other antiplatelet drugs, ticagrelor’s connection to the receptor is reversible, meaning its effect wears off as the drug leaves the system. This mechanism prevents the initial steps of clot formation without requiring the drug to be activated by the body’s metabolism first.
Potential Side Effects
Because ticagrelor prevents blood clots, its most common side effect is an increased tendency to bleed. This can manifest as nosebleeds, easier bruising, or cuts that take longer to stop, and it requires caution in daily activities to avoid injury. Another frequently reported side effect is shortness of breath, known as dyspnea. This sensation is typically mild and often resolves on its own, frequently occurring within the first week of treatment.
Less common side effects can include headache, dizziness, nausea, and joint pain. Serious side effects are uncommon but require immediate medical attention. Signs of major bleeding are emergencies and include:
- Red or black tarry stools
- Pink or brown urine
- Coughing up blood
- Vomit that looks like coffee grounds
Any symptoms of a bleed on the brain, such as a sudden severe headache, weakness on one side of the body, or difficulty speaking, require calling 999 immediately.
Important Drug and Food Interactions
Combining ticagrelor with other medications that affect bleeding significantly increases this risk. This includes other blood thinners like warfarin or apixaban, as well as common over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and naproxen. If a pain reliever is needed, acetaminophen is generally considered a safer option.
Certain prescription medications can interfere with how the body processes ticagrelor. Some antifungal medications, antiviral drugs for HIV, and certain antibiotics can increase the drug’s concentration in the bloodstream, raising the bleeding risk. Conversely, some seizure medications may make ticagrelor less effective. Grapefruit and grapefruit juice can also block an enzyme needed to break down the medication, leading to higher levels in the body and an increased chance of bleeding.
Administration and Dosage Guidelines
Ticagrelor treatment often begins in a hospital with a one-time higher loading dose of 180 mg to help it start working quickly. Following this, the standard maintenance dose is 90 mg taken twice daily for the first year after an event like a heart attack. For long-term prevention in patients with a history of heart attack, the dose may be reduced to 60 mg twice daily.
Ticagrelor is almost always prescribed with a low-dose aspirin (75-100 mg daily), and higher doses of aspirin should be avoided as they can make ticagrelor less effective. If a dose is missed, skip it and take the next one at its regularly scheduled time. Do not stop taking ticagrelor suddenly without consulting a doctor, as this significantly increases the risk of a heart attack or stroke.