When This Medicine Should Not Be Used:
This medicine is not right for everyone. Do not use it if you had an allergic reaction to osimertinib, or if you are pregnant or breastfeeding.

How to Use This Medicine:
Tablet

• Your doctor will tell you how much medicine to use. Do not use more than directed.
• If you cannot swallow the tablet, put it in a glass with 2 ounces of water. Do not use carbonated water or other liquids. Stir until the tablet is in small pieces, and drink the mixture right away. Add 4 to 8 ounces of water to the same glass, and drink it to make sure you get the full dose.
• Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.
• Missed dose: Skip the missed dose, and then go back to your regular schedule. Do not take extra medicine to make up for a missed dose.
• Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.

Drugs and Foods to Avoid:
Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• Some medicines can affect how osimertinib works. Tell your doctor if you are using carbamazepine, phenytoin, rifampicin, rosuvastatin, St John's wort, sulfasalazine, or topotecan.

Warnings While Using This Medicine:

• This medicine may cause birth defects if either partner is using it during conception or pregnancy. Tell your doctor right away if you or your partner becomes pregnant. Women should use effective birth control during treatment and for at least 6 weeks after the last dose. Men should use effective birth control during treatment and for at least 4 months after the last dose.
• Do not breastfeed while you are taking this medicine and for 2 weeks after your last dose.
• Tell your doctor if you have heart disease, heart failure, heart rhythm problems (including QT prolongation), or a history of other lung disease or breathing problems.
• This medicine may cause the following problems:
  
  • Interstitial lung disease or pneumonitis
  • Heart rhythm changes
  • Heart problems, including heart failure
• This medicine could cause infertility. Talk with your doctor before using this medicine if you plan to have children.
• Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
• Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:
Call your doctor right away if you notice any of these side effects:

• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
• Fast, slow, pounding, or uneven heartbeat
• Lightheadedness, dizziness, fainting
• Swelling in your hands, ankles, or feet
• Trouble breathing, chest pain, fever, chills, cough

If you notice these less serious side effects, talk with your doctor:

• Diarrhea
• Rash, dry skin, changes in your nails

If you notice other side effects that you think are caused by this medicine, tell your doctor.
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088