Ticagrelor may cause serious (sometimes fatal) bleeding. Before taking this medication, tell your doctor your medical history, especially about any bleeding problems. Also, before having any surgery, tell your doctor or dentist about all the products you use, especially ticagrelor. Your doctor or dentist will give you specific directions for when to stop taking this medication before your surgery. See also Precautions section. This medication is usually taken with low-dose aspirin, usually 75-100 milligrams once a day. Unless otherwise directed by your doctor, do not take more than 100 milligrams of aspirin daily. Doing so may make ticagrelor work less well. Ask your doctor or pharmacist for details.

Shortness of breath, headache, dizziness, nausea, and nosebleed may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly. Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Although unlikely, serious bleeding may occur. Tell your doctor right away if you have any serious side effects, including: easy bruising/bleeding, bleeding that is severe or that you cannot control (such as a severe nosebleed that you cannot stop), bloody/black stools, vomit with blood or that looks like coffee grounds, bloody/red/pink/dark urine. Tell your doctor right away if you have any serious side effects, including: interrupted breathing during sleep. Get medical help right away if you have any very serious side effects, including: fast/slow/irregular heartbeat, fainting, confusion, trouble speaking, vision changes, signs of a blood clotting problem (such as red/purple pinpoint-sized spots on the skin, fever). A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Some products that may interact with this drug include: mifepristone, other drugs that can cause bleeding/bruising (including other antiplatelet drugs such as clopidogrel, NSAIDs such as ibuprofen/naproxen, "blood thinners" such as dabigatran/warfarin). Other medications can affect the removal of ticagrelor from your body, which may affect how ticagrelor works. Examples include dexamethasone, nefazodone, ritonavir, telithromycin, azole antifungals (such as itraconazole, ketoconazole), HIV protease inhibitors (such as atazanavir), macrolide antibiotics (such as clarithromycin), rifamycins (such as rifampin), drugs used to treat seizures (such as carbamazepine, phenytoin), among others. Check all prescription and nonprescription medicine labels carefully since many medications contain pain relievers/fever reducers (aspirin, NSAIDs such as ibuprofen or naproxen). These drugs are similar to ticagrelor and may increase your risk of side effects if taken together. However, if your doctor has told you to take low-dose aspirin to prevent heart attack or stroke (usually at dosages of 75-100 milligrams a day), you should keep taking the aspirin unless your doctor tells you not to. Ask your doctor or pharmacist for more details. This medication may interfere with certain lab tests (such as platelet functional tests), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.