Tinzaparin belongs to the class of medications called low-molecular-weight heparins. Tinzaparin is an antithrombotic and anticoagulant. Antithrombotic and anticoagulant medications reduce the clotting ability of the blood in order to prevent harmful blood clots from forming in blood vessels.

Tinzaparin is used to prevent and treat conditions known as deep vein thrombosis (DVT) and pulmonary embolism. DVT is associated with the formation of blood clots in the blood vessels in the leg. These blood clots can sometimes travel to the lungs and block blood vessels there, resulting in a serious condition known as pulmonary embolism.

Tinzaparin is also used after hip, knee, or general surgery to prevent harmful blood clots that can form as a result of long periods of inactivity. It is also used to prevent clots in "indwelling" IV lines (long-term IV lines that are "built in") in people who are not at high risk of bleeding.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

Tinzaparin is given by subcutaneous (under the skin) injection only. The dose of tinzaparin varies according to individual circumstances, such as the condition being treated and body weight. Your doctor will choose the dose that is most likely to prevent or treat blood clots but not cause you to bleed easily.

To prevent complications from general surgery or hip surgery, you will receive your first injection of tinzaparin about 2 hours before the surgery and once daily after that for 7 to 10 days. For knee surgery, you will receive your first dose after surgery and once daily for 7 to 10 days. To treat deep vein thrombosis and pulmonary embolism, you will receive your dose once daily until the doctor recommends stopping therapy.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

In some cases, you may need to use tinzaparin injection at home, after you leave the hospital. If you need to give the injection to yourself, your doctor or nurse will show you how to use the ready-to-use prefilled syringes. Be sure to follow the instructions exactly. Ask any questions necessary to be sure you completely understand how to use the medication. Tinzaparin must not be injected into the muscle.

It is important to use this medication exactly as prescribed by your doctor. If you miss a dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store tinzaparin prefilled syringes at room temperature and do not refrigerate. Cold solution may result in painful injection. Syringes are for single use only.

Protect this medication from light and moisture and keep it out of reach of children.

Multi-dose Vials

10,000 anti-Xa IU/mL
Each mL of sterile solution contains 10,000 anti-Xa IU of tinzaparin sodium. Nonmedicinal ingredients: benzyl alcohol, sodium hydroxide (quantity sufficient for pH adjustment), sodium metabisulfite, and water for injection. pH range of the final solution is 5.0 to 7.5.

20,000 anti-Xa IU/mL
Each mL of sterile solution contains 20,000 anti-Xa IU of tinzaparin sodium. Nonmedicinal ingredients: benzyl alcohol, sodium hydroxide (quantity sufficient for pH adjustment), sodium metabisulfite, and water for injection. pH range of the final solution is 5.0 to 7.5.

Pre-filled Syringes

10,000 anti-Xa IU/mL (2500 IU, 3500 IU, 4500 IU syringes)
Each mL of sterile solution contains 10,000 anti-Xa IU of tinzaparin sodium. Nonmedicinal ingredients: sodium acetate·3H2O, sodium hydroxide (quantity sufficient for pH adjustment), and water for injection. pH range of the final solution is 5.0 to 7.5. Preservative-free.

20,000 anti-Xa IU/mL (8000 IU, 10000 IU, 12000 IU, 14000 IU, 16000 IU, 18000 IU syringes)
Each mL of sterile solution contains tinzaparin sodium 20,000 anti-Xa IU. Nonmedicinal ingredients: sodium metabisulfite, sodium hydroxide (quantity sufficient for pH adjustment), and water for injection. pH range of the final solution is 5.0 to 7.5. Preservative-free.

Do not use tinzaparin if you:

• are allergic to tinzaparin or any ingredients of the medication
• are allergic to low-molecular-weight heparins or heparin
• are at risk of heparin-induced thrombocytopenia (decreased number of platelets often associated with increased bleeding)
• have a history of thrombocytopenia
• have a stomach or duodenal ulcer
• have acute or sub-acute bacterial endocarditis (infection of the inner lining of the heart)
• have any conditions associated with increased risk of bleeding
• have bleeding inside the brain (brain hemorrhage)
• have diabetic or hemorrhagic retinopathy (damage to the back of the eye)
• have injuries or have just had an operation involving the brain, spinal cord, eyes, or ears
• have major blood clotting disorders (e.g., hemophilia or idiopathic thrombocytopenic purpura)
• have severe uncontrolled high blood pressure
• are receiving spinal/epidural anesthesia and will be needing multiple high doses of tinzaparin
• have tested positive on an in-vitro platelet aggregation test in the presence of tinzaparin
• have uncontrollable bleeding

Do not use the multi-dose vials for children under 3 years of age.

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who uses this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people using this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• pain and bruising at the injection site

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• bleeding at the injection site
• dizziness
• fainting
• fast or irregular heartbeat
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
• skin rash

Stop using tinzaparin and contact your doctor at once if any of the following side effects occur:

• chest pain
• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of bleeding in the stomach (e.g., bloody, black, or tarry stools, spitting up of blood, vomiting blood or material that looks like coffee grounds)
• signs of stroke (e.g., sudden or severe headache; sudden loss of coordination; vision changes; sudden slurring of speech; or unexplained weakness, numbness, or pain in arm or leg)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Blood clotting: This medication is intended to prevent unwanted blood clots, but it can also make you bleed more easily. You should take care when performing activities that increase your risk of bleeding. Tell your doctor of any signs that your blood is not clotting as quickly. Such symptoms may include black and tarry stools, blood in the urine, easy bruising, or cuts that won't stop bleeding. You will need to have regular blood tests while taking this medication to ensure that you are receiving the correct dose.

Body weight: The safety and effectiveness of tinzaparin for people of high weight (e.g., over 120 kg) and low weight (e.g., under 45 kg) have not been fully established. If you have a high or low body weight, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Heart problems: There have been reports of blood clots in people with prosthetic valves using low molecular weight heparins. Pregnant women with prosthetic heart valves have an increased risk of thromboembolism. If you have prosthetic heart valves your doctor should closely monitor your condition while you are using tinzaparin.

Kidney disease: People with decreased kidney function or kidney disease may experience increased side effects of tinzaparin as a result of the medication building up in the body. If you have kidney disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. You will probably need to have regular blood tests to ensure your kidneys are working properly while you are using this medication.

Liver disease: If you have liver disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. You will probably need to have regular tests to ensure your liver is working properly while you are using this medication.

Potassium levels: Increases in blood levels of potassium occur for a small percentage of people taking medications in the heparin family, including tinzaparin. This may be more likely to happen if you have diabetes or chronic kidney failure, or if you are taking potassium sparing diuretics. Your doctor may want to monitor your potassium levels. If you experience unexplained nausea, fatigue, muscle weakness, or tingling sensations, contact your doctor.

Spinal/epidural hematomas: There is a risk for spinal bleeding and blood clots when tinzaparin is used along with spinal or epidural anesthesia. The risk is greater with higher treatment doses of tinzaparin than with DVT prevention doses and if people are taking other medications that affect blood clotting (e.g., nonsteroidal anti-inflammatory drugs [NSAIDs] such as naproxen or ibuprofen). If you notice a sudden inability to move your body, or have bowel or bladder dysfunction, get medical help immediately.

Stomach ulcers: If you have a history of stomach ulcers, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Pregnancy: The safety of tinzaparin for use during pregnancy has not been established. This medication should not be used during pregnancy unless the benefits outweigh the risks. If your doctor recommends using this medication, the multi-dose vial of tinzaparin should not be used by pregnant women since it contains benzyl alcohol. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if tinzaparin passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children. Children under 3 years old must not receive tinzaparin from multi-dose vials. The preservative, benzyl alcohol, may cause an effect called "gasping syndrome," which may be fatal to small children.

Seniors: Seniors may be at an increased risk of bleeding while using tinzaparin. Tinzaparin is not recommended in seniors over the age of 70 with decreased renal function and in those who have low body weight (<45 kg).

There may be an interaction between tinzaparin and any of the following:

• acetylsalicylic acid (ASA)
• aliskiren
• angiotensin converting enzyme inhibitors (ACEIs; captopril, enalapril, ramipril)
• angiotensin receptor blockers (ARBs; e.g., candesartan, irbesartan, losartan)
• apixaban
• bismuth subsalicylate
• celecoxib
• clopidogrel
• dabigatran
• dasatinib
• deferasirox
• desvenlafaxine
• dipyridamole
• edoxaban
• eplerenone
• feverfew
• garlic
• ginger
• ginkgo
• heparin
• ibrutinib
• other low molecular weight heparins (e.g., dalteparin, enoxaparin, tinzaparin)
• mesalamine
• mifepristone
• nonsteroidal anti-inflammatory medications (NSAIDs; e.g., diclofenac, ibuprofen, indomethacin, naproxen)
• obinutuzumab
• omega-3 fatty acids
• pentoxifylline
• potassium sparing diuretics (water pills; e.g., amiloride, spironolactone)
• potassium supplements
• prasugrel
• rivaroxaban
• selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, fluoxetine, paroxetine, sertraline)
• ticagrelor
• tipranavir
• venlafaxine
• vitamin E
• warfarin

If you are taking any of these, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.