Examples

Histamine H2 acid reducers (commonly called H2 blockers) are available in nonprescription and prescription forms.

H2 blockers are usually taken by mouth, although some can also be given as an injection. Two doses (morning and evening) are typically recommended to control both daytime and nighttime symptoms. Doctors sometimes recommend a single dose, taken at bedtime.

How It Works

H2 blockers reduce the production of stomach acid, which may reduce irritation to the stomach lining and help an ulcer heal.

Why It Is Used

H2 blockers often are used to treat a peptic ulcer or symptoms of indigestion (dyspepsia).

H2 blockers are sometimes used to help prevent ulcers in people who take NSAIDs long-term (for example, for arthritis).

How Well It Works

H2 blockers are often effective treatments for indigestion or heartburn. All four appear to work equally well.

H2 blockers are often able to control the symptoms of an ulcer. H2 blockers are sometimes used in combination with antibiotics to treat H. pylori infections.

H2 blockers can help prevent ulcers caused by daily long-term NSAID use.¹

H2 blockers work better than antacids but not as well as proton pump inhibitors (PPIs) to control symptoms of ulcers and prevent new ulcers.

Side Effects

All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.

Here are some important things to think about:

• Usually the benefits of the medicine are more important than any minor side effects.
• Side effects may go away after you take the medicine for a while.
• If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.

Callor other emergency services right away if you have:

• Trouble breathing.
• Hives.
• Swelling of your face, lips, tongue, or throat.

Common side effects of this medicine include:

• Constipation.
• Diarrhea.
• Dizziness.
• Headache.
• Nausea or vomiting.
• Problems with urination.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Antacids and H2 blockers should not be taken within 1 hour of each other, because the antacid will cause the H2 blockers to take effect more slowly.

Taking medicine

Medicine is one of the many tools your doctor has to treat a health problem. Taking medicine as your doctor suggests will improve your health and may prevent future problems. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.

There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.

Advice for women

If you are pregnant, breast-feeding, or planning to get pregnant, do not use any medicines unless your doctor tells you to. Some medicines can harm your baby. This includes prescription and over-the-counter medicines, vitamins, herbs, and supplements. And make sure that all your doctors know that you are pregnant, breast-feeding, or planning to get pregnant.

Checkups

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.

References

Credits