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.
Allergic reaction: Trastuzumab emtansine may cause severe allergic reactions during or soon after the infusion. The symptoms of this reaction can include flushing, difficulty breathing, fever, chills, low blood pressure, rapid heartbeat or wheezing. If you experience any of these symptoms, notify your doctor immediately. Your doctor will likely want you to stay at the clinic for a period of time after the infusion, so you can be monitored for these effects.
Birth Control: This medication is harmful to a developing baby if it is taken during pregnancy. Women who may become pregnant should use two different forms of birth control while being treated with trastuzumab emtansine and for at least 6 months after completing treatment with this medication.
Bleeding: Trastuzumab emtansine may cause a reduced number of platelets in the blood, which can make it difficult to stop cuts from bleeding. If you notice any signs of bleeding, such as frequent nosebleeds, unexplained bruising, or black and tarry stools, notify your doctor as soon as possible. Your doctor will order routine blood tests to make sure potential problems are caught early.
Severe decreases in platelets seems to occur more often in patients with Asian heritage.
Heart function: This medication can weaken the heart muscles and make it difficult for the heart to pump a normal amount of blood out with each heartbeat. This can then cause symptoms of congestive heart failure. If you experience signs of congestive heart failure, such as difficulty breathing at rest or lying down, swelling of legs, ankles or wrists or you feel tired more easily than usual, contact your doctor as soon as possible.
Interstitial Lung Disease: Rarely, trastuzumab emtansine can cause swelling and irritation in the tissues of the lungs, making it difficult to breathe. If you experience any shortness of breath, dry cough or unexpected weight loss, contact your doctor as soon as possible.
Liver function: Trastuzumab emtansine may reduce liver function and can cause liver failure. If left untreated, this liver failure can be fatal. 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.
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.
Pregnancy: This medication can cause deformities and possibly death to the developing baby if it is used by the mother during pregnancy. Trastuzumab emtansine should not be used during pregnancy due to the risk of harm to the baby. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: It is not known if trastuzumab emtansine 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 less than 18 years of age.