Bruton's Tyrosine Kinase (BTK) Inhibitor Pregnancy: Should not be used during pregnancy; based on animal findings ibrutinib may cause foetal harm and animal studies showed reproductive toxicity. Women of child-bearing potential must use highly effective contraception during treatment and for 3 months after stopping. Breast-feeding should be discontinued during treatment.

Ibrutinib

Brand names: Imbruvica

Ibrutinib is an oral Bruton tyrosine kinase (BTK) inhibitor used in B-cell malignancies including chronic lymphocytic leukaemia, mantle cell lymphoma and Waldenström macroglobulinaemia.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 560 mg (MCL) or 420 mg (CLL, WM) once daily

Route: Oral

Frequency: Once daily, until disease progression or no longer tolerated

SPC for Imbruvica (140 mg film-coated tablet). Treatment should be initiated and supervised by a physician experienced in anticancer medicines. Mantle cell lymphoma (MCL), previously untreated or relapsed/refractory: 560 mg once daily. Chronic lymphocytic leukaemia (CLL) and Waldenstrom's macroglobulinaemia (WM), as single agent or in combination: 420 mg once daily. In combination with venetoclax for CLL, give ibrutinib alone for 3 cycles (1 cycle = 28 days) then 12 cycles of ibrutinib plus venetoclax. Missed dose: may be taken the same day with return to normal schedule next day; do not take extra tablets. Dose adjustments for CYP3A4 inhibitors: reduce to 280 mg once daily with moderate inhibitors; reduce to 140 mg once daily or withhold for up to 7 days with strong inhibitors. Withhold for new/worsening grade 2 cardiac failure, grade 3 cardiac arrhythmias, grade >=3 non-haematological toxicity, grade 3 neutropenia with infection/fever, or grade 4 haematological toxicities, then resume/reduce per the SPC dose-modification tables. Hepatic impairment: mild (Child-Pugh A) 280 mg daily; moderate (Child-Pugh B) 140 mg daily; not recommended in severe (Child-Pugh C). Not recommended in children/adolescents 0-18 years (efficacy not established).

Dose adjustments

Renal

No dose adjustment for mild or moderate renal impairment (creatinine clearance >30 mL/min); maintain hydration and monitor serum creatinine periodically. In severe renal impairment (<30 mL/min) give only if benefit outweighs risk and monitor closely; no data in patients on dialysis.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to the active substance or to any of the excipients
Use of preparations containing St John's Wort is contraindicated in patients treated with ibrutinib

Side effects

Diarrhoea, nausea (very common)
Neutropenia, thrombocytopenia, lymphocytosis (very common)
Musculoskeletal pain, arthralgia (very common)
Haemorrhage / bruising and other bleeding events (very common; major bleeding, some fatal, can occur)
Rash (very common); pneumonia and upper respiratory tract infection (very common); hypertension

Interactions

Warfarin or other vitamin K antagonists: should not be given concomitantly
Anticoagulants or antiplatelet agents: increase the risk of major bleeding; weigh risks and benefits and monitor
Strong or moderate CYP3A inhibitors (e.g. posaconazole, voriconazole): increase ibrutinib exposure - modify dose or interrupt; avoid other strong inhibitors; avoid grapefruit and Seville oranges
Strong CYP3A inducers: may decrease ibrutinib concentrations - avoid coadministration
Fish oil and vitamin E supplements: should be avoided (bleeding risk)

Clinical monograph

How it works

It irreversibly inhibits BTK, blocking B-cell receptor signalling and thereby impairing malignant B-cell proliferation, survival and migration.

Prescribing in practice

It increases the risk of bleeding and of atrial fibrillation, so assess cardiovascular risk and exercise caution with concomitant anticoagulants and antiplatelets.
It is a CYP3A substrate, so co-administration with strong CYP3A inhibitors or inducers requires dose adjustment or avoidance.
Consider holding therapy peri-operatively because of bleeding risk and monitor for infections and hypertension.

Monitoring

Monitor full blood count, cardiac rhythm and blood pressure, and remain alert for bleeding and infection throughout treatment.

Counselling the patient

Report any unusual bruising or bleeding, palpitations, breathlessness or signs of infection.
Take it consistently and avoid grapefruit and Seville oranges, which can raise drug levels.
Tell your team before any surgery or dental procedure.

Evidence & guidelines

Ibrutinib is recommended by NICE for chronic lymphocytic leukaemia and other B-cell malignancies on the basis of randomised trials such as RESONATE.

Reference: NICE TA429; RESONATE trial; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Acalabrutinib [Specialist drug] · Bruton's tyrosine kinase (BTK) inhibitor

Pathways