Synopsis
Select UFH, low-molecular-weight heparin or fondaparinux for treatment and prevention, prescribe a usable weight-based regimen and recognise accumulation, heparin-induced thrombocytopenia and reversal limits.
- LMWH is preferred for most stable VTE treatment because its weight-based effect is predictable and routine APTT monitoring is unnecessary.
- UFH is useful when rapid titration and short offset are needed, in selected severe renal failure, or when thrombolysis, embolectomy or imminent surgery is possible.
- For acute VTE, enoxaparin 1 mg/kg SC every 12 hours is preferred in symptomatic PE, obesity, cancer, recurrent VTE or proximal iliac thrombosis; 1.5 mg/kg once daily is reserved for uncomplicated lower-risk patients.
Key red flags
New thrombosis, skin necrosis, systemic reaction after an IV heparin bolus or a platelet fall of more than 50% typically 5–10 days after exposure suggests immune HIT even if the count remains normal.
Investigation priorities
Select dose, establish platelets and haemoglobin and anticipate renal accumulation.
Management branches
DVT or PE is confirmed without haemodynamic instability or immediate procedure.
- Record actual weight, renal function, platelets, bleeding risk, cancer, pregnancy and intended oral-transition pathway.
- Give the indication-appropriate treatment dose, favouring enoxaparin 1 mg/kg twice daily in symptomatic PE or high-recurrence contexts.
Key medicines
Enoxaparin for acute VTEGive 1 mg/kg subcutaneously every 12 hours for obesity, symptomatic PE, cancer, recurrent VTE or proximal iliac thrombosis; 1.5 mg/kg once daily is an option for uncomplicated patients at low recurrence risk.
Enoxaparin prophylaxisFor medical or high-risk surgical prophylaxis a common regimen is 40 mg subcutaneously once daily; in severe renal impairment the SmPC regimen is 20 mg once daily, with start time and duration set by procedure and mobility.