1. Ranitidine oral tablet is available as both a generic and brand-name drug. Brand name: Zantac.
  2. Ranitidine comes as a tablet, capsule, and syrup that are taken by mouth. It also comes as an injectable solution.
  3. Ranitidine oral tablet is used to treat intestinal and stomach ulcers, gastroesophageal reflux disease (GERD), and conditions where your stomach makes too much acid, including a rare condition called Zollinger-Ellison syndrome. It’s also used to heal acid-related damage to the lining of the esophagus.

Ranitidine is a drug that’s available in a prescription version and an over-the-counter version. This article only addresses the prescription version. Prescription ranitidine comes as an oral tablet, oral capsule, or oral syrup. It also comes as an injectable solution.

Ranitidine oral tablet is available as the brand-name drug Zantac. It’s also available as a generic drug. Generic drugs usually cost less than the brand-name version. In some cases, they may not be available in all strengths or forms as the brand-name drug.

Why it’s used

Ranitidine oral tablet is used to treat several conditions, including:

Ranitidine may be used as part of a combination therapy. This means you may need to take it with other medications.

Ranitidine is typically used for short-term treatment, especially for GERD. If you’re taking this drug for other conditions, you may need long-term treatment. You may need to take it for several weeks or months.

How it works

Ranitidine belongs to a class of drugs called histamine receptor antagonists. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions.

Ranitidine works by reducing the amount of acid in your stomach.

Q:

Is ranitidine considered an antacid?

A:

No. Ranitidine works by reducing the amount of acid your stomach makes. Antacids, on the other hand, neutralize the acid that your stomach has already made.

The Healthline Medical TeamAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

Ranitidine oral tablet may cause drowsiness as well as other side effects.

More common side effects

The more common side effects of ranitidine oral tablet can include:

  • headache
  • constipation
  • diarrhea
  • nausea and vomiting
  • stomach discomfort or pain

If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.

Serious side effects

Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include:

  • Inflammation of your liver, with symptoms such as:
    • yellowing of your skin or the whites of your eyes
    • tiredness
    • dark urine
    • stomach pain
  • Changes in your brain function, with symptoms such as:
    • confusion
    • agitation
    • depression
    • hallucinations (seeing or hearing something that isn’t there)
    • blurry vision
  • Abnormal heart rate, with symptoms such as:
    • fast heart rate
    • tiredness
    • shortness of breath

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.

Ranitidine oral tablet can interact with other medications, vitamins, or herbs you may be taking. An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well.

To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking. To find out how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Examples of drugs that can cause interactions with ranitidine are listed below.

Drugs you should not use with ranitidine

Delavirdine: Do not take delavirdine with ranitidine. Doing so can cause dangerous effects. Ranitidine reduces the levels of delavirdine in your body. This means delavirdine won’t work as well.

Interactions that increase your risk of side effects

Taking ranitidine with certain medications raises your risk of side effects from these drugs. Examples of these drugs include:

  • Procainamide: Taking high doses of ranitidine with procainamide can cause side effects from procainamide.
  • Warfarin: Taking ranitidine with warfarin may increase your risk of bleeding or blood clots. Your doctor may watch you more closely if you’re taking these drugs together.
  • Midazolam and triazolam: Taking ranitidine with either of these drugs raises your risk of extreme drowsiness that can last a long time.
  • Glipizide: Taking these drugs together can increase your risk for low blood sugar. You may need to test your blood sugar or test it more often when starting or stopping ranitidine.

Interactions that can make your drugs less effective

When certain drugs are used with ranitidine, they may not work as well. This is because the amount of these drugs in your body may be decreased. Examples of these drugs include:

  • Atazanavir: If you need to take these drugs together, your doctor will tell you how long you should wait between doses of these medications.
  • Gefitinib: If you take gefitinib and ranitidine with the antacid sodium bicarbonate, gefitinib may not work as well. Talk to your doctor if you’re taking gefitinib and ranitidine.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.

All possible dosages and drug forms may not be included here. Your dosage, drug form, and how often you take the drug will depend on:

  • your age
  • the condition being treated
  • the severity of your condition
  • other medical conditions you have
  • how you react to the first dose

Drug forms and strengths

Generic: Ranitidine

  • Form: oral tablet
  • Strengths: 150 mg, 300 mg

Brand: Zantac

  • Form: oral tablet
  • Strengths: 150 mg, 300 mg

Dosage for duodenal (intestinal) ulcer

Adult dosage (ages 17–64 years)

  • Treatment of an active intestinal ulcer: 150 mg taken twice per day or 300 mg taken once per day. If you take one dose, take it after your evening meal or at bedtime.
  • Maintenance therapy: 150 mg taken once per day at bedtime.

Child dosage (ages 1 month–16 years)

  • Treatment of an active intestinal ulcer
    • Typical dosage: 2–4 mg/kg of body weight twice per day.
    • Maximum dosage: 300 mg per day.
  • Maintenance therapy
    • Typical dosage: 2–4 mg/kg taken once per day.
    • Maximum dosage: 150 mg per day.

Child dosage (younger than 1 month)

It hasn’t been confirmed that this drug is safe and effective for children younger than 1 month.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects.

Your doctor may start you on a lower dosage or a different treatment schedule. This can help keep levels of the drug from building up too much in your body.

Special considerations

If you have moderate or severe kidney disease, your doctor may start you on 150 mg once per day. They may increase the dosage to twice per day.

Dosage for gastric (stomach) ulcer

Adult dosage (ages 17–64 years)

  • Treatment of an active stomach ulcer: 150 mg twice per day.
  • For maintenance therapy: 150 mg once per day at bedtime.

Child dosage (ages 1 month–16 years)

  • Treatment of an active gastric ulcer
    • Typical dosage: 2–4 mg/kg of body weight twice per day.
    • Maximum dosage: 300 mg per day.
  • Maintenance therapy
    • Typical dosage: 2–4 mg/kg taken once per day.
    • Maximum dosage: 150 mg per day.

Child dosage (younger than 1 month)

It hasn’t been confirmed that this drug is safe and effective for children younger than 1 month.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects.

Your doctor may start you on a lower dosage or a different treatment schedule. This can help keep levels of the drug from building up too much in your body.

Special dosage considerations

If you have moderate or severe kidney disease, your doctor may start you on 150 mg once per day. They may increase your dosage to twice per day.

Dosage for gastroesophageal reflux disease (GERD)

Adult dosage (ages 17–64 years)

  • Typical dosage: 150 mg taken twice per day.

Child dosage (ages 1 month–16 years)

  • Typical dosage: 5–10 mg/kg of body weight per day in two divided doses.

Child dosage (younger than 1 month)

It hasn’t been confirmed that this drug is safe and effective for children younger than 1 month.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects.

Your doctor may start you on a lowered dosage or a different treatment schedule. This can help keep levels of the drug from building up too much in your body.

Special dosage considerations

If you have moderate or severe kidney disease, your doctor may start you on 150 mg taken once per day. They may increase your dosage to twice per day.

Dosage for erosive esophagitis

Adult dosage (ages 17–64 years)

  • Treatment of active disease: 150 mg four times per day.
  • For maintenance therapy: 150 mg twice per day

Child dosage (ages 1 month-16 years)

  • Typical dosage: 5–10 mg/kg of body weight per day in two divided doses.

Child dosage (younger than 1 month)

It hasn’t been confirmed that this drug is safe and effective for children younger than 1 month.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects.

Your doctor may start you on a lowered dosage or a different treatment schedule. This can help keep levels of the drug from building up too much in your body.

Special considerations

If you have moderate or severe kidney disease, your doctor may start you on 150 mg once per day. They may increase your dosage to twice per day.

Dosage for hypersecretory conditions

Adult dosage (ages 17–64 years)

  • Typical dosage: 150 mg twice per day.
  • Dosage increases: Your doctor may change your dosage as needed.
  • Maximum dosage: 6,000 mg (or 6 g) per day.

Child dosage (ages 0–17 years)

It hasn’t been confirmed that this drug is safe and effective in people younger than 18 years for this condition.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects.

Your doctor may start you on a lowered dosage or a different treatment schedule. This can help keep levels of the drug from building up too much in your body.

Special dosage considerations

If you have moderate or severe kidney disease, your doctor may start you on 150 mg taken once per day. They may increase your dosage to twice per day.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always speak with your doctor or pharmacist about dosages that are right for you.

Ranitidine is used for long-term or short-term treatment. It comes with serious risks if you don’t take it as prescribed.

If you stop taking the drug suddenly or don’t take it at all: You may still have stomach pain caused by high amounts of acid in your stomach. This may make your condition worse.

If you miss doses or don’t take the drug on schedule: Your medication may not work as well or may stop working completely. For this drug to work well, a certain amount needs to be in your body at all times.

If you take too much: Ranitidine overdose is very rare. You would usually have to take much more than recommended before having overdose symptoms. However, if you take too much ranitidine, you could have dangerous levels of the drug in your body. Symptoms of an overdose of this drug can include:

  • trouble walking
  • low blood pressure (may make you feel dizzy or faint)

If you think you’ve taken too much of this drug, call your doctor or seek guidance from the American Association of Poison Control Centers at 1-800-222-1222 or through their online tool. But if your symptoms are severe, call 911 or go to the nearest emergency room right away.

What to do if you miss a dose: Take your dose as soon as you remember. But if you remember just a few hours before your next scheduled dose, take only one dose. Never try to catch up by taking two doses at once. This could result in dangerous side effects.

How to tell if the drug is working: You should have less stomach pain.

General

  • Take this drug at the time(s) recommended by your doctor.
  • You can take it with or without food.
  • You can also cut or crush the tablet.

Storage

  • Store this drug carefully at room temperature. Keep it between 59°F and 86°F (15°C and 30°C).
  • Keep this drug away from light.
  • Don’t store this medication in moist or damp areas, such as bathrooms.

Refills

A prescription for this medication is refillable. You should not need a new prescription for this medication to be refilled. Your doctor will write the number of refills authorized on your prescription.

Travel

When traveling with your medication:

  • Always carry your medication with you. When flying, never put it into a checked bag. Keep it in your carry-on bag.
  • Don’t worry about airport X-ray machines. They can’t hurt your medication.
  • You may need to show airport staff the pharmacy label for your medication, so carry the original prescription-labeled container with you.
  • Don’t put this medication in your car’s glove compartment or leave it in the car, especially when the weather is very hot or very cold.

Clinical monitoring

You and your doctor should monitor certain health issues. This can help make sure you stay safe while you take this drug. These issues can include your kidney function. Your doctor may do blood tests to check how well your kidneys are working. If your kidneys aren’t working well, your doctor may lower your dosage of this drug.

There are other drugs available to treat your condition. Some may be better suited for you than others. Talk to your doctor about other drug options that may work for you.

Ranitidine oral tablet comes with several warnings.

Allergy warning

Ranitidine can cause a severe allergic reaction. Symptoms can include:

  • trouble breathing
  • swelling of your throat or tongue
  • fever
  • rash

If you have these symptoms, call 911 or go to the nearest emergency room.

Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could cause death.

Warnings for people with certain health conditions

For people with kidney problems: If you have kidney problems or a history of kidney disease, you may not be able to clear this drug from your body well. This may increase the levels of ranitidine in your body and cause more side effects.

For people with liver problems: If you have liver problems or a history of liver disease, you may not be able to process this drug well. This may increase the levels of ranitidine in your body and cause more side effects.

For people with acute porphyria (an inherited blood disorder): You shouldn’t use this drug if you have a history of an acute porphyria attack. This drug can trigger an acute porphyric attack.

For people with gastric cancer: This drug reduces the amount of acid in your stomach. This can help improve the symptoms of your gastrointestinal condition. However, if your symptoms are caused by a cancerous gastric tumor, you may still have the tumor. This drug does not treat cancer.

Warnings for other groups

For pregnant women: Research in animals has not shown that this drug poses a risk to a pregnancy. However, animal studies do not always predict the way humans would respond. And there aren’t enough studies of this drug in pregnant humans to see if it is harmful.

That said, this drug should only be used in pregnancy if clearly needed. Call your doctor right away if you become pregnant while taking this drug.

For women who breastfeeding: You should tell your doctor before taking this drug. Ranitidine may pass into breast milk and cause side effects in a child who is breastfed. You may need to ask your doctor to help you weigh the benefits of breastfeeding versus taking this drug.

For seniors: The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects. In rare cases, this drug may cause confusion, agitation, depression, and hallucinations. These problems happen most often in seniors who are very ill.

For children: Ranitidine has not been confirmed as safe and effective in children younger than 1 month for any condition. Ranitidine has not been confirmed as safe and effective in people younger than 18 years for conditions where the stomach makes too much acid. These conditions include Zollinger-Ellison syndrome.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.