Patients with severe renal impairment may show reduced elimination of tinzaparin. Increased risk of death observed in elderly patients with renal impairment. Certain patients are at increased risk of bleeding (risk factors include bacterial endocarditis, congenital or acquired bleeding disorders, active ulcerative or angiodysplastic GI diseases, severe uncontrolled hypertension, history of hemorrhagic stroke, use shortly after brain, spinal, or ophthalmology surgery, patients treated concomitantly with platelet inhibitors, recent GI bleeding, thrombocytopenia or platelet defects, severe liver disease, hypertensive or diabetic retinopathy, or patients undergoing invasive procedures). Hyperkalemia might occur (risk factors include renal dysfunction, concomitant use of potassium-sparing diuretics or potassium supplements, hematoma in body tissues). Rare cases of thrombocytopenia occurred. Contraindicated in history of heparin-induced thrombocytopenia. Rare cases of thrombocytopenia with thrombosis occurred. Use caution in congenital or drug-induced thrombocytopenia or platelet defects. Reduced tinzaparin clearance observed in moderate renal impairment (CrCl ≤50 mL/minute). Patients with severe renal impairment (CrCl <30 mL/minute) had 24% decrease in clearance. Use with caution in renal insufficiency or avoid use, particularly in patients of advanced age with concomitant renal impairment. This product contains benzyl alcohol and should be used with caution in pregnant women (large amounts of benzyl alcohol associated with fatal toxicity gasping syndrome in neonates). Product derived from porcine intestinal mucosa. Contains sodium metabisulfite which may cause allergic-type reactions, including anaphylactic symptoms and life-threatening asthmatic episodes in susceptible people (more frequently in asthmatics). For subcutaneous use only, do not administer intramuscularly or intravenously. Not to be used interchangeably (unit for unit) with heparin or any other low molecular weight heparins. Patients with recent or anticipated neuraxial anesthesia (epidural or spinal anesthesia) at risk of spinal or epidural hematoma and subsequent paralysis. Patient should be observed closely for bleeding and signs and symptoms of neurological impairment if therapy is administered during or immediately following diagnostic lumbar puncture, epidural anesthesia, or spinal anesthesia.