Do not use Zantac if:

• you are allergic to any ingredient in Zantac;
• you have a history of porphyria (a blood disease).

• Do not drive or perform other possibly unsafe tasks until you know how you react to it.
• Zantac may interfere with certain lab tests, including urine protein tests. Be sure your doctor and lab personnel know you are taking Ranitidine.
• Lab tests, including liver function, may be performed while you use Zantac. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
• Zantac should be used with extreme caution in children younger than 1 month old; safety and effectiveness in these children have not been confirmed.
• Pregnancy and breast-feeding: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Zantac while you are pregnant. Zantac is found in breast milk. Do not breast-feed while taking Zantac.

Check with your doctor if any of these most common side effects persist or become bothersome:

• constipation; diarrhea; headache; nausea; stomach upset.

• severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue; unusual hoarseness); confusion; dark urine; fast, slow, or irregular heartbeat; fever, chills, or sore throat; hallucinations; severe or persistent headache or stomach pain; unusual bruising or bleeding; yellowing of the eyes or skin.

Zantac is to be used only by the patient for whom it is prescribed. Do not share it with other people.