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Zantac

Generic Name: ranitidine (ra NI ti deen)
Brand Name: Zantac

Medically reviewed on May 3, 2018

What is ranitidine?

Ranitidine is a histamine-2 blocker that works by reducing the amount of acid your stomach produces.

Ranitidine is used to treat and prevent ulcers in the stomach and intestines. It also treats conditions in which the stomach produces too much acid, such as Zollinger-Ellison syndrome. Ranitidine also treats gastroesophageal reflux disease (GERD) and other conditions in which acid backs up from the stomach into the esophagus, causing heartburn.

Ranitidine may also be used for purposes not listed in this medication guide.

Important Information

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Before taking this medicine

Heartburn can mimic early symptoms of a heart attack. Get emergency medical help if you have chest pain that spreads to your jaw or shoulder and you feel anxious or light-headed.

You should not use ranitidine if you are allergic to it.

Ask a doctor or pharmacist if this medicine is safe to use if you have:

  • kidney disease;

  • liver disease; or

  • porphyria (a genetic enzyme disorder that causes symptoms affecting the skin or nervous system).

Ask a doctor before using this medicine if you are pregnant or breast-feeding.

This medicine may contain phenylalanine. Check the medication label if you have phenylketonuria (PKU).

How should I take ranitidine?

Use exactly as directed on the label, or as prescribed by your doctor.

Your doctor may recommend an antacid to help relieve pain. Carefully follow your doctor's directions about the type of antacid to use, and when to use it.

Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

It may take up to 8 weeks before your ulcer heals. Keep using the medication as directed and call your doctor if your symptoms do not improve after 6 weeks.

This medicine can affect the results of certain medical tests. Tell any doctor who treats you that you are using ranitidine.

Store at room temperature away from moisture, heat, and light.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include lack of coordination, feeling light-headed, or fainting.

What should I avoid while taking ranitidine?

Avoid drinking alcohol. It can increase the risk of damage to your stomach.

Ranitidine side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using ranitidine and call your doctor at once if you have:

  • stomach pain, loss of appetite;

  • dark urine, jaundice (yellowing of the skin or eyes);

  • fever, chills, cough with mucus, chest pain, feeling short of breath;

  • fast or slow heart rate;

  • easy bruising or bleeding; or

  • problems with your skin or hair.

Common side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

What other drugs will affect ranitidine?

Many drugs can affect ranitidine. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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