Crizotinib is a type of targeted therapy called a tyrosine kinase inhibitor. Crizotinib works by targeting and blocking receptors found on the cancer cells, which in turn blocks tumor growth. This medication acts specifically on tumors that have an abnormality in a gene called ALK (anaplastic lymphoma kinase). Your oncology team will test your tumor for this abnormality, which must be present to receive the medication.
How to take crizotinib
Crizotinib comes in a capsule form and is taken twice a day. The capsule should be swallowed whole (do not break or chew) with a glass of water, with or without food. If you miss a dose, you can take it as soon as you remember up to 6 hours before the next scheduled dose. If it is less than 6 hours until the next dose, do not take the missed dose. Do not take two doses at once to make up for the one you missed.
The blood levels of this medication can be affected by certain foods and medications, so they should be avoided. These include (but are not limited to): grapefruit, grapefruit juice, ketoconazole, rifampin, phenytoin, St. John's wort, and fentanyl. Be sure to tell your healthcare provider about all medications and supplements you take.
Side effects of crizotinib
Below are some of the possible side effects and suggestions for dealing with them. Be sure to tell your oncology team if you are experiencing any of these problems.
Some patients develop visual changes, typically within the first 2 weeks of treatment. This can include seeing flashes of light, blurry vision, sensitivity to light or seeing "floaters". Notify your healthcare provider right away if you notice any changes in your vision.
Some patients taking crizotinib have developed a severe lung condition called pneumonitis (an inflammation or swelling of the lung tissue). Notify your healthcare provider right away if you develop any new or worsening symptoms, including shortness of breath, trouble breathing, cough or fever.
Nausea and/or Vomiting
Take anti-nausea medications if prescribed. If you continue to have nausea or vomiting, notify your doctor or nurse so they can help you manage this side effect. In addition, dietary changes may help. Avoid things that may worsen the symptoms, such as heavy or greasy/fatty, spicy or acidic foods (lemons, tomatoes, oranges). Try antacids, (e.g. milk of magnesia, calcium tablets such as Tums), saltines, or ginger ale to lessen symptoms. Read the Nausea & Vomiting Tip Sheet for more suggestions.
Call your doctor or nurse if you are unable to keep fluids down for more than 12 hours or if you feel lightheaded or dizzy at any time.
Your oncology team can recommend medications to relieve diarrhea. Also, try eating low-fiber, bland foods, such as white rice and boiled or baked chicken. Avoid raw fruits, vegetables, whole grain breads, cereals and seeds. Soluble fiber is found in some foods and absorbs fluid, which can help relieve diarrhea. Foods high in soluble fiber include: applesauce, bananas (ripe), canned fruit, orange sections, boiled potatoes, white rice and products made with white flour, oatmeal, cream of rice, cream of wheat, and farina. Drink 8-10 glasses on non-alcoholic, un-caffeinated fluid a day to prevent dehydration. Read Low Fiber Diet for Diarrhea for more tips.
Low White Blood Cell Count (Leukopenia or Neutropenia)
White blood cells (WBC) are important for fighting infection. While receiving treatment, your WBC count can drop, putting you at a higher risk of getting an infection. You should let your doctor or nurse know right away if you have a fever (temperature greater than 100.4°), sore throat or cold, shortness of breath, cough, burning with urination, or a sore that doesn't heal.
Tips to preventing infection:
For more suggestions, read the Neutropenia Tip Sheet.
Exposure of an unborn child to this medication could cause birth defects, so you should not become pregnant or father a child while on this medication and for at least 3 months after stopping the medication. Effective birth control is necessary during treatment, even if your menstrual cycle stops or you believe your sperm is affected. Do not breastfeed while taking this medication.
Crizotinib can cause liver toxicity, which your doctor may monitor for using blood tests called liver function tests. If you develop elevations in your liver function tests, your healthcare provider may need to lower your dose or stop the medication. Notify your healthcare provider if you notice yellowing of the skin or eyes, your urine appears dark or brown or pain in your abdomen as these can be signs of liver toxicity.
Crizotinib can cause changes in your heartbeat (QT prolongation), fast or abnormal heartbeats. Notify your healthcare provider right away if you feel abnormal heartbeats or if you feel dizzy or faint.