Tinzaparin

How it works

It binds antithrombin to accelerate inhibition of activated factor Xa more than thrombin, producing a predictable anticoagulant effect with a longer half-life than unfractionated heparin.

Prescribing in practice

• Bleeding is the main risk, and the drug accumulates in significant renal impairment so use with caution and consider anti-Xa monitoring or an alternative as renal function declines, particularly in the elderly.
• It is contraindicated with active major bleeding and a history of heparin-induced thrombocytopenia, and neuraxial anaesthesia requires careful timing relative to dosing to avoid spinal haematoma.
• Treatment doses are calculated by body weight and given once daily, and some multidose presentations contain benzyl alcohol making them unsuitable in pregnancy and neonates.

Monitoring

Monitor full blood count for thrombocytopenia, renal function, and signs of bleeding, using anti-Xa activity rather than activated partial thromboplastin time where monitoring is needed.

Counselling the patient

• You or a carer can be taught to give the injection under the skin, rotating sites.
• Report unusual bruising, bleeding that will not stop, or black stools.
• Do not stop suddenly without advice if treating a clot.

Evidence & guidelines

Its efficacy in venous thromboembolism prophylaxis and treatment is supported by randomised trials and reflected in NICE guidance and the SPC.