Ranitidine injection is used in people who are hospitalized to treat certain conditions in which the stomach produces too much acid or to treat ulcers (sores in the lining of the stomach or intestine) that were not successfully treated with other medications. Ranitidine injection is also used on a short-term basis in people who cannot take oral medication

• to treat ulcers,
• to prevent ulcers from returning after they have healed,
• to treat gastroesophageal reflux disease (GERD, a condition in which backward flow of acid from the stomach causes heartburn and injury of the esophagus [tube between the throat and the stomach]),
• and to treat conditions where the stomach produces too much acid, such as Zollinger-Ellison syndrome (tumors in the pancreas and small intestine that caused increased production of stomach acid).

Ranitidine injection is in a class of medications called H₂ blockers. It works by decreasing the amount of acid made in the stomach.

Ranitidine injection comes as a solution (liquid) to be mixed with another fluid and injected intravenously (into a vein) over 5 to 20 minutes. Ranitidine may also be injected into a muscle. It is usually given every 6 to 8 hours, but may also be given as a constant infusion over 24 hours.

You may receive ranitidine injection in a hospital or you may administer the medication at home. If you will be receiving ranitidine injection at home, your healthcare provider will show you how to use the medication. Be sure that you understand these directions, and ask your healthcare provider if you have any questions.

Before receiving ranitidine injection,

• tell your doctor and pharmacist if you are allergic to ranitidine, famotidine, cimetidine, nizatidine (Axid), any other medications, or any of the ingredients in ranitidine injection. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: anticoagulants ('blood thinners') such as warfarin (Coumadin), atazanavir (Reyataz, in Evotaz), delavirdine (Rescriptor), gefitinib (Iressa), glipizide (Glucotrol), ketoconazole (Nizoral), midazolam (by mouth), procainamide, and triazolam (Halcion). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or have ever had porphyria (an inherited blood disease that may cause skin or nervous system problems), or kidney or liver disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while receiving ranitidine injection, call your doctor.

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Unless your doctor tells you otherwise, continue your normal diet.

Ranitidine injection may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• headache
• pain, burning, or itching in the area where the medication was injected

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or get emergency medical treatment:

• slow heartbeat
• hives
• itching
• rash
• difficulty breathing or swallowing
• swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
• hoarseness
• upset stomach
• extreme tiredness
• unusual bleeding or bruising
• lack of energy
• loss of appetite
• pain in the upper right part of the stomach
• yellowing of the skin or eyes
• flu-like symptoms

Ranitidine injection may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests to check your body's response to ranitidine injection.

Before having any laboratory test, tell your doctor and the laboratory personnel that you are using ranitidine injection.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.