Erlotinib is used to treat lung and pancreatic cancer. It works by slowing or stopping the growth of cancer cells.

Take this medication by mouth on an empty stomach (at least 1 hour before or 2 hours after a meal) as directed by your doctor, usually once daily.

The dosage is based on your medical condition, response to treatment, and other medications you may be taking. Be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Medications that lower stomach acid (such as antacids, H2 blockers including ranitidine) may prevent erlotinib from working. Ask your doctor or pharmacist how to use these medications safely with erlotinib.