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Ranitidine, Oral

What are other names for this medicine?

Type of medicine: H2 blocker

Generic and brand names: ranitidine, oral; Zantac; Zantac 75; Zantac 150; Zantac 300; Zantac EFFERdose

What is this medicine used for?

This medicine is taken by mouth to treat duodenal ulcers, erosive esophagitis, gastroesophageal reflux disease (GERD), and benign gastric ulcers, and to reduce production of stomach acid. It may also be used for other conditions as determined by your healthcare provider.

Some forms of this medicine are available without a healthcare provider's prescription. These products relieve heartburn, acid indigestion, and sour stomach.

What should my healthcare provider know before I take this medicine?

Before taking this medicine, tell your healthcare provider if you have ever had:

  • an allergic reaction to any medicine
  • kidney or liver disease.
  • phenylketonuria (PKU). The dissolving tablet contains phenylalanine.
  • porphyria (nerve pain or sensitivity to sunlight)

Females of childbearing age: Tell your healthcare provider if you are pregnant or plan to become pregnant. Do not breast-feed while taking this medicine without your healthcare provider's approval.

How do I take it?

Take this medicine regularly for as long as your healthcare provider prescribes, even if you feel better or do not have any pain.

Take this medicine according to the directions on the package or as your healthcare provider recommends. You may take this medicine with or without food. It works best when taken with meals.

Your healthcare provider may want you to take antacids when you start taking this medicine to control pain until the medicine takes effect. If your healthcare provider prescribes an antacid, take it an hour before or after this medicine.

If you are taking the EFFERdose tablets or granules form of this medicine, dissolve in 8 ounces of water. Drink right away. Do not save any unused mixture. Do not chew, place the tablets on your tongue, or swallow the tablets whole.

If you miss a dose, take it as soon as you remember unless it is almost time for the next scheduled dose. In that case, skip the missed dose and take the next one as directed. Do not take double doses. If you are not sure of what to do if you miss a dose, or if you miss more than one dose, contact your healthcare provider.

What should I watch out for?

Aspirin, other medicines, alcohol, coffee, and other substances can irritate your stomach and add to your problem. Follow your healthcare provider's advice about use of other medicines and alcohol and about which foods to avoid. Contact your healthcare provider if your pain continues.

What are the possible side effects?

Along with its needed effects, your medicine may cause some unwanted side effects. Some side effects may be very serious. Some side effects may go away as your body adjusts to the medicine. Tell your healthcare provider if you have any side effects that continue or get worse.

Life-threatening (Report these to your healthcare provider right away. If you cannot reach your healthcare provider right away, get emergency medical care or call 911 for help): Allergic reaction (hives; itching; rash; trouble breathing; tightness in your chest; swelling of your lips, tongue, and throat).

Serious (report these to your healthcare provider right away): Confusion, unusual bruising or bleeding, sore throat, fever, irregular heartbeat, hallucinations, severe muscle or joint pain, yellow skin or eyes.

Other: Headache, dizziness, drowsiness, nausea, diarrhea, breast tenderness.

What products might interact with this medicine?

When you take this medicine with other medicines, it can change the way this or any of the other medicines work. Nonprescription medicines, vitamins, natural remedies, and certain foods may also interact. Using these products together might cause harmful side effects. Talk to your healthcare provider if you are taking:

  • antacids containing calcium or magnesium such as Maalox, Mylanta, and Tums (take them at least 1 hour before or after this medicine)
  • antifungals such as fluconazole (Diflucan), itraconazole (Sporanox), and ketoconazole (Nizoral)
  • antibiotics such as cefpodoxime (Vantin) and ceftibuten (Cedax)
  • oral medicines for diabetes such as glipizide (Glucotrol), metformin (Glucophage, Fortamet) and glyburide (DiaBeta, Micronase, Glynase)
  • procainamide (Pronestyl)
  • sucralfate (Carafate) (take at least 2 hours before or after this medicine)
  • theophylline (Elixophyllin, Theo-24, Theochron)
  • warfarin (Coumadin),

Keep a list of all your medicines (prescription, nonprescription, supplements, natural remedies, and vitamins) with you. Be sure that you tell all healthcare providers who treat you about all the products you are taking.

How should I store this medicine?

Store this medicine at room temperature. Keep the container tightly closed. Protect it from heat, high humidity, and bright light.


This advisory includes selected information only and may not include all side effects of this medicine or interactions with other medicines. Ask your healthcare provider or pharmacist for more information or if you have any questions.

Ask your pharmacist for the best way to dispose of outdated medicine or medicine you have not used. Do not throw medicine in the trash.

Keep all medicines out of the reach of children.

Do not share medicines with other people.

Developed by McKesson Corporation
Published by McKesson Corporation.
Last modified: 2007-07-09
Last reviewed: 2007-03-12
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Copyright © 2007 McKesson Corporation and/or one of its subsidiaries. All Rights Reserved.
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