The recommended dosage of Xalkori® is one 250mg capsule taken by mouth twice daily. The capsules may be taken with or without food. Treatment should continue as long it is benefiting the patient.

Crizotinib is a tyrosine kinase inhibitor and can affect anaplastic lymphoma kinase or ALK. 
Everyone has the ALK gene in their cells. When a part of it breaks off and reattaches in the wrong way, it becomes an abnormal ALK gene. This may cause the cell to multiply out of control and cause a type of lung cancer to grow. This type of lung cancer is called ALK-positive (ALK+) non-small cell lung cancer (NSCLC).  Crizotinib treats ALK+ NSCLC that has spread to other parts of the body. By blocking the action of the abnormal ALK gene, crizotinib may shrink or slow the growth of tumours.

Crizotinib may cause the following side effects:

• swelling of hands and feet
• constipation or diarrhea
• nausea
• vomiting
• visual disturbances
• fatigue
• insomnia
• tingling or numbness in hands or feet
• taste disturbances

Possible serious side effects include:

• Heart rhythm disturbance – Tell your doctor or nurse right away if you experience dizziness, fainting, palpitations (irregular heartbeat), seizures, or chest discomfort.
• Liver problems–Tell your doctor or nurse right away if you are feeling more tired than usual, your skin and whites of your eyes turn yellow, if you experience stomach pain, your urine turns dark or brown (tea color), you have nausea or vomiting, you have decreased appetite, you bleed or bruise more easily
  than normal, or if you have itching.
• Lung inflammation - contact physician if you have any new or worsening symptoms including difficulty breathing, cough or fever.
• Vision problems- crizotinib may cause partial or complete loss of vision in one or both eyes. Contact physician right away if you have any loss of vision or if you have any change in vision such as difficulty seeing out of one or both eyes. 

• Crizotinib should be prescribed and used under the supervision of a doctor experienced with drugs used to treat cancer.  
• Crizotinib may prolong the QT interval. Patients with congenital long QT syndrome (a heart condition) should not use crizotinib.  
• Crizotinib may cause inflammation of the lungs.  If you have any new or worsening symptoms, including difficulty breathing, cough, or fever during treatment, let your doctor know.
• Use with caution if you have:
  • heart problems
  • history of fainting
  • low blood levels of potassium, calcium or magnesium
  • diabetes
  • kidney or liver problems
  • peripheral neuropathy

Crizotinib may interact with other medications.  Inform your pharmacist and doctor if you are taking:

• medicines for heart rhythm problems (anti-arrhythmics) 
• medicines for depression such as amitryptyline and imipramine
• medicines for psychoses such as ziprasidone, and haloperidol 
• azithromycin, clarithromycin, moxifloxacin, or ciprofloxacin
• ketoconazole or itraconazole
• other cancer medicines such as sunitinib, nilotinib, lapatinib, and vandetanib
• formoterol and salmeterol
• medicines that decrease the level of potassium such as water pills
• some medicines for high blood pressure, which may also decrease the heart rate such as verapamil, diltiazem, and atenolol

Use in pregnancy and breastfeedng:  Not recommended for use.  Consult your doctor or pharmacist.