[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [ALK and ROS1 inhibitors](https://durgical.com/en/pharmacology/classes/alk-and-ros1-inhibitors/) › Crizotinib # Crizotinib ## ALK and ROS1 inhibitors? ALK and ROS1 inhibitors ## High alert? An error with this medicine can cause serious harm: double checks and protocols are used. ## Pregnancy: avoid? Avoid in pregnancy. Can harm the fetus: a pregnancy test is done before starting, effective contraception is used during treatment and for a time afterwards (by women and by men… The first ALK inhibitor: an oral drug for ALK- or ROS1-positive lung cancer that also blocks MET. Watch the eyes, the pulse and the liver. Updated Nov 1, 2026 Also called: PF-02341066 ## Quick facts **Group** [ALK and ROS1 inhibitors](https://durgical.com/en/pharmacology/classes/alk-and-ros1-inhibitors/) **Target** ALK receptor tyrosine kinase (also ROS1 and MET) **Key effects** Visual disturbances · Nausea · Taste changes **Monitor** ALK or ROS1 test · Heart rate · Eye examination before **ATC** L01ED01 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 ✂**ALK receptor tyrosine kinase (also ROS1 and MET)**Crizotinib ⓘ The figure shows crizotinib in the ATP pocket of the human ALK kinase domain. **Target in 3D:** ALK receptor tyrosine kinase (also ROS1 and MET). PDB structure 2XP2 (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/2XP2) · Drag to rotate · pinch to zoom Crizotinib competes with ATP in the kinase domain of ALK, ROS1 and MET (hepatocyte growth factor receptor). In tumours where a rearrangement has fused ALK or ROS1 to another gene, the fused kinase is permanently active; blocking it stops the downstream growth and survival signals and the tumour shrinks. It was developed as a MET inhibitor and became the first drug approved for ALK-positive cancers. - A rearrangement fuses ALK or ROS1: the kinase is always on - Crizotinib fills the ATP pocket of ALK, ROS1 and MET - Growth and survival signals stop; the tumour shrinks ## Indications - Metastatic non-small cell lung cancer that is ALK-positive or ROS1-positive. [Lung cancer →](https://durgical.com/en/conditions/lung-cancer/) - Relapsed or refractory ALK-positive systemic anaplastic large cell lymphoma in children and young adults. [Non-Hodgkin lymphoma →](https://durgical.com/en/conditions/non-hodgkin-lymphoma/) - ALK-positive inflammatory myofibroblastic tumour that is unresectable, relapsed or refractory. ## Adverse effects ### Common - Visual disturbances: blurred or double vision, light sensitivity, flashes, floaters - Nausea, vomiting, diarrhoea or constipation - Swelling of the hands and legs (oedema) - Taste changes, decreased appetite, mouth sores - Numbness or tingling of the hands and feet (neuropathy) ### Serious (rare, important) - Hepatotoxicity - Pneumonitis (interstitial lung disease) - Bradycardia and QT prolongation - Severe vision loss ## Contraindications - Used with caution in long QT syndrome, slow heart rate or heart failure ## Key interactions **Strong CYP3A4 inhibitors (clarithromycin, itraconazole, ketoconazole, ritonavir) and grapefruit** Raise its levels and its toxicity. **Strong CYP3A4 inducers (rifampicin, carbamazepine, phenytoin, St John's wort)** Lower its levels and can make it fail. **Drugs that slow the heart or prolong the QT interval** Additive bradycardia and arrhythmia risk. ## What is monitored - ALK or ROS1 test of the tumour before starting - Liver tests before and during treatment - Heart rate, blood pressure and ECG - Eye examination before and during treatment ## Administration and safety - Oral; swallowed whole, never split, crushed, chewed or opened. - With or without food; grapefruit and its juice are avoided. ## Pregnancy and breastfeeding Avoid in pregnancy. Can harm the fetus: a pregnancy test is done before starting, effective contraception is used during treatment and for a time afterwards (by women and by men with partners who could conceive), and breastfeeding is avoided. ## Nursing care - Check pulse and blood pressure at each visit; report a slow or irregular pulse, dizziness or fainting. - Ask about vision changes and advise caution with driving until the patient knows how the drug affects them. - Teach to report cough, breathlessness or fever, and dark urine or right upper abdominal pain. - Confirm a negative pregnancy test before the first dose and teach contraception during treatment and afterwards. ## Pharmacokinetics **Absorption** Oral capsules, with or without food. **Metabolism** Liver, mainly CYP3A4/5. ## Memory aid «CRIZotinib, three keys and two eyes»: it locks ALK, ROS1 and MET, and its tell-tale effect is in the eyes (flashes and blurring). ## Test yourself Think of the answer, then tap the question to see it. ## Which test must be positive before crizotinib is used in lung cancer? An ALK or ROS1 rearrangement in the tumour. ## A patient on crizotinib sees flashes of light and blurred images. What is this? A typical visual disturbance of crizotinib; it is reported and an eye examination is arranged. ## Which vital sign is checked closely on crizotinib, and why? Heart rate, because it can cause bradycardia (and QT prolongation). [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/crizotinib/) [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. **Pregnancy: avoid** Avoid in pregnancy. Can harm the fetus: a pregnancy test is done before starting, effective contraception is used during treatment and for a time afterwards (by women and by men… ## Connections ## Related drugs 2 - [Alectinib](https://durgical.com/en/pharmacology/alectinib/) - [Lorlatinib](https://durgical.com/en/pharmacology/lorlatinib/) ## Related conditions 2 - [Lung cancer](https://durgical.com/en/conditions/lung-cancer/) - [Non-Hodgkin lymphoma](https://durgical.com/en/conditions/non-hodgkin-lymphoma/) [← Back to the class: ALK and ROS1 inhibitors](https://durgical.com/en/pharmacology/classes/alk-and-ros1-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: [Crizotinib: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a612018.html) (MedlinePlus (U.S. National Library of Medicine), 2022); [Crizotinib - NCI](https://www.cancer.gov/about-cancer/treatment/drugs/crizotinib) (National Cancer Institute, 2022); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=L01ED01) (WHO Collaborating Centre for Drug Statistics Methodology, 2026). ## **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/crizotinib/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/crizotinib/