[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Kinase inhibitors (targeted oncology)](https://durgical.com/en/pharmacology/classes/kinase-inhibitors/) › Ibrutinib # Ibrutinib ## Kinase inhibitors (targeted oncology)? Kinase inhibitors (targeted oncology) ## High alert? An error with this medicine can cause serious harm: double checks and protocols are used. Oral covalent BTK inhibitor that switches off B-cell receptor signalling in CLL and Waldenström macroglobulinaemia; watch bleeding and atrial fibrillation. Updated Nov 1, 2026 ## Quick facts **Group** [Kinase inhibitors (targeted oncology)](https://durgical.com/en/pharmacology/classes/kinase-inhibitors/) **Target** Bruton tyrosine kinase (BTK) **Used for** Chronic lymphocytic leukaemia **Key effects** Diarrhoea · Bruising and minor bleeding · Rash **Monitor** Blood counts · Pulse rhythm and blood pressure **ATC** L01EL01 No doses: the clinician sets them by the current guideline. On this page - The basics Mechanism of action - Indications - Adverse effects - Pharmacokinetics - Memory aid - Clinical What the labels mean - Safety Contraindications - Key interactions - What is monitored - Administration and safety - Pregnancy and breastfeeding - Nursing care - Study Test yourself - Connections Connections ## Mechanism of action ✂**Bruton tyrosine kinase (BTK)**Ibrutinib ⓘ The crystal shows ibrutinib in the ATP site of the human BTK kinase domain, next to cysteine 481, the residue it bonds covalently. **Target in 3D:** Bruton tyrosine kinase (BTK). PDB structure 5P9J (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/5P9J) · Drag to rotate · pinch to zoom Malignant B cells in CLL and related lymphomas depend on signals from the B-cell receptor, which pass through Bruton tyrosine kinase. Ibrutinib binds covalently to cysteine 481 near the ATP site and permanently inactivates BTK. B-cell receptor signalling fails, so the malignant B cells stop proliferating and die. - B-cell receptor signals run through BTK - Ibrutinib bonds covalently to BTK cysteine 481 - BTK is permanently switched off - Malignant B cells stop proliferating and die ## Indications - Chronic lymphocytic leukaemia and small lymphocytic lymphoma. [Chronic lymphocytic leukaemia →](https://durgical.com/en/conditions/chronic-lymphocytic-leukaemia/) - Waldenström macroglobulinaemia. [MGUS and Waldenström macroglobulinaemia →](https://durgical.com/en/conditions/mgus-and-waldenstrom-macroglobulinaemia/) - Chronic graft-versus-host disease after failure of other systemic treatment. ## Adverse effects ### Common - Diarrhoea, nausea - Bruising and minor bleeding - Musculoskeletal pain - Rash - Fatigue, fever - Neutropenia, thrombocytopenia, anaemia ### Serious (rare, important) - Major bleeding - Atrial fibrillation and other arrhythmias - High blood pressure - Serious infections ## Contraindications - No absolute contraindications; caution with anticoagulants, bleeding disorders, arrhythmia and severe liver impairment ## Key interactions **Strong CYP3A inhibitors (azoles, clarithromycin, grapefruit, Seville orange)** Raise ibrutinib levels and toxicity. **CYP3A inducers (rifampicin, St John's wort)** Lower its levels; avoided. **Anticoagulants and antiplatelet drugs** Add to the bleeding risk. **Surgery** Usually held for several days before and after surgery because of bleeding risk. ## What is monitored - Blood counts - Pulse rhythm and blood pressure; ECG if palpitations - Signs of bleeding - Signs of infection ## Administration and safety - Oral; swallowed whole at about the same time each day. - Check the name carefully: kinase inhibitors with similar «-tinib» names are not interchangeable. - Grapefruit and Seville oranges are avoided; plenty of fluids are encouraged. ## Pregnancy and breastfeeding Can harm the fetus; women and men with female partners use contraception during treatment and for a month after. ## Nursing care - Check pulse for irregularity and blood pressure at each visit. - Review the medicine list for anticoagulants, antiplatelets and CYP3A interactions. - Remind the team that ibrutinib is held around surgery and procedures. - Teaching: report palpitations, dizziness, black stools, blood in urine, severe headache or fever. ## Pharmacokinetics **Absorption** Oral; food increases absorption. **Metabolism** Liver, mainly CYP3A; liver impairment raises exposure. **Elimination** Metabolites mainly in the faeces. **Half-life** Short, about 4 to 6 hours, but BTK stays inhibited because the bond is covalent. ## Memory aid «IBRUTinib BRUises and flutters»: bleeding and atrial fibrillation; it bonds BTK at Cys481 for good. ## Test yourself Think of the answer, then tap the question to see it. ## Which enzyme does ibrutinib inhibit, and how? Bruton tyrosine kinase, by a covalent bond to cysteine 481. ## Which arrhythmia is typical of ibrutinib? Atrial fibrillation. ## Why is grapefruit avoided with ibrutinib? It inhibits CYP3A and raises ibrutinib levels. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/ibrutinib/) [More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology) ## What the labels mean **High alert** An error with this medicine can cause serious harm: double checks and protocols are used. ## Connections ## Related drugs 1 - [Rituximab](https://durgical.com/en/pharmacology/rituximab/) ## Related conditions 2 - [Chronic lymphocytic leukaemia](https://durgical.com/en/conditions/chronic-lymphocytic-leukaemia/) - [MGUS and Waldenström macroglobulinaemia](https://durgical.com/en/conditions/mgus-and-waldenstrom-macroglobulinaemia/) [← Back to the class: Kinase inhibitors (targeted oncology)](https://durgical.com/en/pharmacology/classes/kinase-inhibitors/) Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given. Sources: [Ibrutinib: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a614007.html) (MedlinePlus (U.S. National Library of Medicine), 2024); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=L01EL01) (WHO Collaborating Centre for Drug Statistics Methodology, 2026); [eEML - Electronic Essential Medicines List](https://list.essentialmeds.org/) (World Health Organization, 2025). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/pharmacology/ibrutinib/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/ibrutinib/