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 Alecensaro (Alectinib).

Heart disease: Alecensaro (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 Alecensaro (Alectinib) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Alecensaro (Alectinib), 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 Alecensaro (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 Alecensaro (Alectinib) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Alecensaro (Alectinib), and whether any special monitoring is needed.

Kidney function: Alecensaro (Alectinib) may cause decreased kidney function. If you experience signs of kidney problems, such as a change in the amount or colour of urine, increased urination at night, blood in the urine, or swelling in the feet or legs, contact your doctor.

Liver function:  Liver disease or reduced liver function may cause Alecensaro (Alectinib) to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how Alecensaro (Alectinib) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Alecensaro (Alectinib), and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking Alecensaro (Alectinib).

Alecensaro (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 Alecensaro (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 Alecensaro (Alectinib), contact your doctor immediately.

Muscle effects:  Muscle damage has been associated with the use of Alecensaro (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: Alecensaro (Alectinib) 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 Alecensaro (Alectinib) 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: Alecensaro (Alectinib) should not be used during pregnancy unless the benefits outweigh the risks. Women of childbearing age who are taking Alecensaro (Alectinib) and women whose partners are taking Alecensaro (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 Alecensaro (Alectinib), contact your doctor immediately.

Breast-feeding: It is not known if Alecensaro (Alectinib) passes into breast milk. If you are a breast-feeding mother and are taking Alecensaro (Alectinib), it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using Alecensaro (Alectinib) have not been established for children.

Seniors: People over the age of 75 are more likely to experience severe side effects of taking Alecensaro (Alectinib).