Women who are pregnant or planning to get pregnant should not be given Kadcyla. Kadcyla can cause embryo death and birth defects. It’s important that you don’t get pregnant while you’re getting Kadcyla; you must use effective birth control.
The most common side effects of Kadcyla are:
- bone and joint pain
- muscle pain
- low blood platelet count
- liver problems
- nerve damage
- low red blood cell count
- low potassium levels
Kadcyla also can cause other serious side effects. While these serious side effects are rare (about 1-2% of people treated with Kadcyla will experience them), it’s important to know about them:
- Heart problems: Kadcyla may cause serious heart problems, including some that don’t have symptoms, such as reduced heart function, and some that do have symptoms, such as congestive heart failure. Symptoms to watch for include swelling of the ankles or legs, shortness of breath, cough, or weight gain of more than 5 pounds in less than 24 hours.
- Lung problems: Kadcyla may cause inflammation of the lungs, which can be life-threatening. Symptoms include trouble breathing, cough, tiredness, and fluid in the lungs.