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Bypass Agent — Haemophilia with Inhibitors

Recombinant Factor VIIa

Brand names: NovoSeven

Recombinant factor VIIa (eptacog alfa) is a bypassing agent used to treat and prevent bleeding in haemophilia A or B with inhibitors, and in certain other rare bleeding disorders such as factor VII deficiency and Glanzmann thrombasthenia.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

In pharmacological amounts it activates the coagulation cascade on the surface of activated platelets, generating thrombin and a fibrin clot largely independently of factors VIII and IX, thereby bypassing inhibitors.

Prescribing in practice

  • Thromboembolic events, including arterial and venous thrombosis, are a recognised risk, particularly in patients with predisposing cardiovascular factors, so it should be used with caution and for the shortest effective duration.
  • It is administered by intravenous injection and dosing for bleeding episodes is repeated according to response under haematology guidance.
  • Management of bleeding in inhibitor patients should follow specialist advice and current prescribing references.

Monitoring

Monitor clinical haemostatic response and remain vigilant for signs of thrombosis, as routine coagulation tests do not reliably reflect efficacy.

Counselling the patient

  • Explain that this medicine helps blood to clot when standard factor replacement does not work because of inhibitors.
  • Advise reporting symptoms suggesting a clot, such as chest pain, breathlessness or limb swelling.

Evidence & guidelines

Recombinant factor VIIa is an established bypassing agent for haemophilia with inhibitors in UK haematology practice and the SPC.

Reference: FAST Trial (Mayer et al. NEJM 2008); BSH Haemophilia with Inhibitors Guidelines; UKHCDO; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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