Get emergency medical help if you have signs of an allergic reaction to Kadcyla: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Some side effects may occur during the injection. Tell your caregiver right away if you feel cold, light-headed, feverish or sweaty, or have chest tightness, rapid heartbeats, or trouble breathing.
Call your doctor at once if you have:
easy bruising, unusual bleeding, purple or red spots under your skin;
coughing up blood or vomit that looks like coffee grounds;
bloody or tarry stools;
chest pain, wheezing, dry cough, feeling short of breath;
unusual tiredness, feeling light-headed;
pale skin, cold hands and feet;
numbness, tingling, or burning pain in your hands or feet;
sudden numbness or weakness (especially on one side of the body), severe headache, slurred speech, balance problems;
liver problems - loss of appetite, stomach pain (upper right side), dark urine, jaundice (yellowing of the skin or eyes); or
signs of tumor cell breakdown - confusion, weakness, muscle cramps, nausea, vomiting, fast or slow heart rate, decreased urination, tingling in your hands and feet or around your mouth.
Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.
Common Kadcyla side effects may include:
easy bruising or bleeding (especially nosebleeds);
nausea, constipation;
joint or muscle pain;
headache; or
feeling tired.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Kadcyla side effects (more detail)
