Thrombocytopenia

Definition

Isolated platelet count below the normal range. For patients with bi- or pancytopenia refer to the appropriate RefHelp page.

Please also see the guidance on thrombocytopenia in pregnancy.  

Please note:

• Thrombocytopenia can be drug-induced, therefore review all medication and consider discontinuing any drugs that might be implicated
• Drugs most often associated with thrombocytopenia include:
• heparin (including LMWH)
• quinine
• bendroflumethiazide
• sulphonamides
• sulphonylureas
• phenytoin
• methotrexate
• ranitidine
• NSAIDs.
• Heparin induced thrombocytopenia (HIT) – please see below for detail.
• For patients with a high alcohol intake, it may be appropriate to repeat the FBC to see if thrombocytopenia has resolved following a period of abstinence.
• For patients with a high alcohol intake, deranged LFTs +/- USS abdomen, consider GI referral initially.

Heparin Induced Thrombocytopenia (HIT)

This is a rare complication associated with significant risk of thrombosis. It usually occurs within 15 days of starting heparin/LMWH.  If the platelet count is low – or has dropped by more than 50% – since heparin initiation, please discuss the case with the on-call haematologist.