Zantac is used for:

Treating certain conditions that cause your body to make too much stomach acid (eg, Zollinger-Ellison syndrome). It is also used to treat ulcers of the small intestine that have not responded to other treatment. It may be used as a short-term alternative to oral ranitidine, in patients who are not able to take medicine by mouth. It may also be used for other conditions as determined by your doctor.

Zantac is an H2-receptor blocker. It works by blocking the action of histamine in the stomach. This reduces the amount of acid the stomach makes. Reducing stomach acid helps to reduce heartburn, to heal irritation of the esophagus, and to heal ulcers of the stomach or intestines.

Do NOT use Zantac if:

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

Contact your doctor or health care provider right away if any of these apply to you.

Before using Zantac :

Some medical conditions may interact with Zantac . Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:
if you are pregnant, planning to become pregnant, or are breast-feeding
if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
if you have allergies to medicines, foods, or other substances
if you have a history of kidney or liver problems
if you have abnormal blood electrolyte levels or a history of irregular heartbeat

Some MEDICINES MAY INTERACT with Zantac . However, no specific interactions with Zantac are known at this time.

Ask your health care provider if Zantac may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Zantac :

Use Zantac as directed by your doctor. Check the label on the medicine for exact dosing instructions.
Zantac is usually given as an injection at your doctor's office, hospital, or clinic. If you will be using Zantac at home, a health care provider will teach you how to use it. Be sure you understand how to use Zantac . Follow the procedures you are taught when you use a dose. Contact your health care provider if you have any questions.
Do not use Zantac if it contains particles, is cloudy or discolored, or if the vial is cracked or damaged.
Keep this product, as well as syringes and needles, out of the reach of children and pets. Do not reuse needles, syringes, or other materials. Ask your health care provider how to dispose of these materials after use. Follow all local rules for disposal.
You may take antacids while you are using Zantac if you are directed to do so by your doctor.
Continue to use Zantac even if you feel well. Do not miss any doses.
If you miss a dose of Zantac , use it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not use 2 doses at once.

Ask your health care provider any questions you may have about how to use Zantac .

Important safety information:

Zantac may rarely cause drowsiness, dizziness, or blurred vision. These effects may be worse if you take it with alcohol or certain medicines. Use Zantac with caution. 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 Zantac .
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 .

Possible side effects of Zantac :

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Constipation; diarrhea; headache; nausea; stomach upset.
Seek medical attention right away if any of these SEVERE side effects occur:

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.