Tinzaparin is used to treat serious blood clots, usually in the legs. Tinzaparin may also be used to treat blood clots in the lungs. It is usually used with another "blood thinner" medication (warfarin). If untreated, blood clots can travel to the lungs, heart, or brain, causing serious (possibly fatal) breathing problems, heart attack, or stroke.

This drug may also be used to prevent blood clots after certain surgeries with an increased risk of blood clots (such as knee or hip replacement). It may also be used to prevent clotting in certain catheters used by patients on hemodialysis.

Tinzaparin is known as a "blood thinner" (anticoagulant). It is a type of heparin called low-molecular-weight heparin. It works by blocking certain natural substances in the blood that cause clotting.

Read the Patient Information Leaflet if available from your pharmacist before you start using tinzaparin and each time you get a refill. Ask your health care professional how to prepare and use this medication. If you have any questions, ask your doctor or pharmacist.

Inject this medication under the skin as directed by your doctor, usually once daily. The injection is given in the stomach/abdomen. Do not inject into a muscle. The dosage and length of treatment are based on your medical condition, weight, and response to treatment.

Before using, check this product for particles or discoloration. If either is present, do not use the liquid. Do not mix any other medication in the same injection. Before injecting each dose, clean the skin you are going to inject into (the injection site) with rubbing alcohol. Change the injection site each time to lessen injury under the skin. To lessen bruising, do not rub the injection site after a shot. Learn how to store and discard medical supplies safely.

When treating a blood clot, another "blood thinner" (warfarin) is usually started 1 to 3 days after you start using tinzaparin. Your doctor will direct you to use both of these medications until the warfarin is working well. Do not stop either of these medications until your doctor directs you to stop.

To prevent blood clots due to surgery, your doctor may direct you to start using this medication before or after surgery and continue for several days. Follow your doctor's directions closely.

This medication may also be given by injection into a vein (to prevent clotting of certain hemodialysis catheters) by a health care professional as directed by your doctor.

Use this medication regularly to get the most benefit from it. To help you remember, use it at the same time each day.

Pain, bruising, redness, and swelling at the injection site may occur. Headache, nosebleed, and fever may also 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.

Tell your doctor right away if you have any serious side effects, including:

• nausea/vomiting that doesn't stop
• loss of appetite
• easy bleeding/bruising
• dark urine
• yellowing eyes/skin

This medication may rarely cause serious bleeding. (See also Warning section.) Tell your doctor right away if you have any signs of serious bleeding, including:

• shortness of breath
• coughing up blood
• chest pain
• cold/blue fingers or toes
• unusual dizziness
• fast/irregular heartbeat
• joint/muscle pain
• mental/mood changes (such as confusion)
• difficulty moving
• numbness/tingling
• severe stomach/abdominal pain
• bloody/black/tarry stools
• red/pinkish urine
• vomit that looks like coffee grounds

Get medical help right away if you have any very serious side effects, including:

• headache that is severe or doesn't go away
• seizures
• fainting
• trouble speaking
• vision problems
• weakness on one side of the body

Rarely, males may have a painful or prolonged erection lasting 4 or more hours. If this occurs, stop using this drug and get medical help right away, or permanent problems could occur.

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.

See also Warning section.

Before using tinzaparin, tell your doctor or pharmacist if you are allergic to it; or to heparin or pork products; or if you have any other allergies. This product may contain inactive ingredients (such as sulfites, benzyl alcohol), which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using tinzaparin, tell your doctor or pharmacist your medical history, especially of:

• a past blood-clotting problem because of heparin (heparin-induced thrombocytopenia)
• artificial heart valves
• bleeding/blood problems (such as low platelet count, bleeding ulcer)
• a certain eye problem (diabetic retinopathy)
• high blood pressure
• infections in the heart (bacterial endocarditis)
• kidney disease
• liver disease
• stomach/intestinal problems (such as recent ulcers, colitis)
• stroke
• recent spinal procedures or puncture
• spine problems (such as spinal deformity)
• recent surgery (especially on the eye, brain, or spine)

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Limit alcohol while taking this drug because it may increase the risk of stomach bleeding.

To lower the chance of getting cut, bruised, or injured, use caution with sharp objects like razors and nail cutters, and avoid activities such as contact sports.

Older adults may be more sensitive to the side effects of this drug, especially bleeding.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor. If you become pregnant or think you may be pregnant, tell your doctor right away. Since the benzyl alcohol in tinzaparin can affect the unborn baby, a preservative-free product should be used by pregnant women if possible.

It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

See also Warning section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug include:

• mifepristone
• other drugs that can cause bleeding/bruising (including antiplatelet drugs such as clopidogrel, NSAIDs such as ketorolac, "blood thinners" such as dabigatran)

Check all prescription and nonprescription medicine labels carefully since many medications contain pain relievers/fever reducers (NSAIDs such as ibuprofen, naproxen, aspirin) which can increase the risk of bleeding when used with tinzaparin. However, if your doctor has told you to take low-dose aspirin to prevent heart attack or stroke (usually 81-162 milligrams a day), you should keep taking the aspirin unless your doctor tells you not to. Ask your doctor or pharmacist for more details.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: bleeding that doesn't stop.

Do not share this medication with others.

Lab and/or medical tests (such as complete blood count, kidney/liver function) should be done while you are using this medication. Keep all medical and lab appointments. Consult your doctor for more details.

If you miss a dose, use it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Use your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).