Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
Heart disease: Alectinib can cause very low heart rate. If you have heart conditions with low heart rate such as certain types of arrhythmia, congestive heart failure, sick sinus syndrome or certain types of heart block, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
If you experience signs of slow heartbeat, such as dizziness, lightheadedness and fainting, let your doctor know as soon as possible.
Gastrointestinal perforation: Rarely, people taking alectinib experience a gastrointestinal perforation. This is a condition where a hole forms through the walls of the digestive tract and is a medical emergency. If you have risk factors for this type of complication, such as a history of diverticulitis, cancer that has spread to the digestive tract or are taking other medications that may cause gastrointestinal perforation, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Liver function: Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking this medication.
Alectinib may also cause harm to the liver. If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.
Lung inflammation: Rarely, some people taking alectinib have experienced lung inflammation (interstitial lung disease), causing difficulty breathing. This complication can be serious and sometimes fatal. If you experience new or worsening shortness of breath or cough (with or without fever) at any time while you are taking alectinib, contact your doctor immediately.
Muscle effects: Muscle damage has been associated with the use of alectinib. Report any unexplained muscle pain, tenderness, weakness or cramps, or any brown or discoloured urine to your doctor immediately, particularly if you are also experiencing malaise (a general feeling of being unwell) or fever.
Sensitivity to sunlight: This medication may increase the sensitivity of the skin to sunlight, increasing the risk of sunburn. Avoid exposure to sunlight for long periods of time, particularly between the hours of 10 am and 2 pm, while you are taking this medication and for 7 days after completing treatment. Wear a broad-spectrum sunscreen and lip balm with an SPF of 50 or higher. If you notice any unusual skin rash or peeling, contact your doctor immediately.
Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. Women of childbearing age who are taking alectinib and women whose partners are taking alectinib should use an effective method of birth control, such as condoms, during treatment and for at least 3 months after stopping the medication. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: It is not known if alectinib passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
Children: The safety and effectiveness of using this medication have not been established for children.