Lapatinib Side Effects and Warnings

What are the precautions when taking this medicine?

• If you have heart disease, talk with healthcare provider.

• If you have liver disease, talk with healthcare provider.

• If you have lung disease, talk with healthcare provider.

• Check medicines with healthcare provider. This medicine may not mix well with other medicines.

• Do not take St John's wort with this medicine. It may make this medicine less effective.

• Talk with healthcare provider before using aspirin, aspirin-containing products, other pain medicines, blood thinners, garlic, ginseng, ginkgo, or vitamin E.

• Avoid grapefruit and grapefruit juice.

• Use birth control that you can trust to prevent pregnancy while taking this medicine.

What are some possible side effects of this medicine?

• Nausea or vomiting. Small frequent meals, frequent mouth care, sucking hard, sugar-free candy, or chewing sugar-free gum may help.

• Diarrhea.

• Belly pain.

• Skin irritation.

• Headache.

• Hair loss. Hair usually grows back when medicine is stopped.

• Back pain.

• Rash.

• Mouth irritation. Frequent mouth care with a soft toothbrush or cotton swabs and rinsing mouth may help.

• Feeling tired or weak.

• Heart damage can rarely occur.

• Liver damage can rarely occur.

Reasons to call healthcare provider immediately

• If you suspect an overdose, call your local poison control center or emergency department immediately.

• Signs of a life-threatening reaction. These include wheezing; chest tightness; fever; itching; bad cough; blue skin color; fits; or swelling of face, lips, tongue, or throat.

• Signs or symptoms of infection. These include a fever of 100.5 degrees or higher, chills, severe sore throat, ear or sinus pain, cough, increased sputum or change in color, painful urination, mouth sores, wound that will not heal, or anal itching or pain.

• Difficulty breathing.

• Fast heartbeat.

• Severe dizziness or passing out.

• Severe belly pain.

• Severe nausea or vomiting.

• Severe diarrhea.

• Feeling extremely tired or weak.

• Unusual bruising or bleeding.

• Dark urine or yellow skin or eyes.

• Not able to eat.

• Any rash.

• No improvement in condition or feeling worse.