Alteplase is a thrombolytic (THROM-bo-LIT-ik) drug, sometimes called a "clot-busting" drug. It helps your body produce a substance that dissolves unwanted blood clots.

Alteplase is used to treat a stroke caused by a blood clot or other obstruction in a blood vessel. Alteplase is also used to prevent death from a heart attack (acute myocardial infarction).

Alteplase is also used to treat a blood clot in the lung (pulmonary embolism).

Alteplase is also used to dissolve blood clots that have formed in or around a catheter placed inside a blood vessel. This improve the flow of medicines injected in through the catheter, or blood drawn out through the catheter.

Alteplase may also be used for purposes not listed in this medication guide.

You should not be treated with alteplase if you are allergic to it, or if you have:

• active bleeding inside your body;
• a brain tumor or aneurysm (dilated blood vessel);
• a history of head injury or surgery on your brain or spinal cord within the past 3 months; or
• severe or uncontrolled high blood pressure;
• a bleeding or blood clotting disorder such as hemophilia;
• bleeding inside your brain (if you are receiving alteplase to treat a stroke); or
• a recent history of stroke (if you are receiving alteplase for pulmonary embolism).

If possible before you receive alteplase, tell your doctor if you have ever had:

• any type of stroke;
• bleeding in your brain, stomach, intestines, or urinary tract;
• high blood pressure;
• heart problems;
• an infection of the lining of your heart (also called bacterial endocarditis);
• a serious injury or major surgery;
• severe bruising or infection around a vein where an IV was placed;
• an organ biopsy;
• eye problems caused by diabetes;
• liver or kidney disease; or
• if you are pregnant or breastfeeding.

In an emergency situation it may not be possible to tell your caregivers if you are pregnant or breast-feeding. Make sure any doctor caring for your pregnancy or your baby knows you have received this medicine.

Use Cathflo Activase (Injectable) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Alteplase increases your risk of bleeding, which can be severe or fatal. Call your doctor or seek emergency medical attention if you have bleeding that will not stop. Bleeding may occur from a surgical incision, or from the skin where a needle was inserted during a blood test or while receiving injectable medication. You may also have bleeding on the inside of your body, such as in your stomach or intestines, kidneys or bladder, brain, or within the muscles.

Call your doctor or get emergency medical help if you have signs of bleeding, such as:

• sudden headache, feeling very weak or dizzy;
• bleeding gums, nosebleeds;
• easy bruising;
• bleeding from a wound, incision, catheter, or needle injection;
• bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds;
• red or pink urine;
• heavy menstrual periods or abnormal vaginal bleeding; or
• sudden numbness or weakness (especially on one side of the body), slurred speech, problems with vision or balance.

Also call your doctor at once if you have:

• chest pain or heavy feeling, pain spreading to the jaw or shoulder, nausea, sweating, general ill feeling;
• swelling, rapid weight gain, little or no urination;
• severe stomach pain, nausea, and vomiting;
• darkening or purple discoloration of your fingers or toes;
• very slow heartbeats, shortness of breath, feeling light-headed;
• sudden severe back pain, muscle weakness, numbness or loss of feeling in your arms or legs;
• increased blood pressure--severe headache, blurred vision, pounding in your neck or ears, anxiety, nosebleed; or
• pancreatitis--severe pain in your upper stomach spreading to your back, nausea and vomiting.

Bleeding is the most common side effect of alteplase.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Ask your doctor before taking aspirin or ibuprofen (Motrin, Advil) shortly after you have received alteplase. These medications can increase your risk of bleeding.

Avoid activities that may increase your risk of bleeding or injury. Use extra care to prevent bleeding while shaving or brushing your teeth.