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Histamine H 2-receptor Antagonists  (Systemic)

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Brand Names

Some commonly used brand names are:

In the U.S.—

  • Axid3
  • Axid AR3
  • Mylanta AR Acid Reducer2
  • Pepcid2
  • Pepcid I.V.2
  • Pepcid AC Acid Controller2
  • Pepcid RPD2
  • Tagamet1
  • Tagamet HB1
  • Zantac4
  • Zantac EFFERdose Granules4
  • Zantac EFFERdose Tablets4

In Canada—

  • Acid Control2
  • Act2
  • Apo-Cimetidine1
  • Apo-Famotidine2
  • Apo-Nizatidine3
  • Apo-Ranitidine4
  • Axid3
  • Dyspep HB2
  • Gen-Cimetidine1
  • Gen-Famotidine2
  • Gen-Ranitidine4
  • Maalox H2 Acid Controller2
  • Novo-Cimetine1
  • Novo-Famotidine2
  • Novo-Ranitidine4
  • Nu-Cimet1
  • Nu-Famotidine2
  • Nu-Ranit4
  • Pepcid2
  • Pepcid AC2
  • Pepcid I.V.2
  • Peptol1
  • PMS-Cimetidine1
  • Tagamet1
  • Ulcidine2
  • Ulcidine-HB2
  • Zantac4
  • Zantac 754

Note:

For quick reference, the following histamine H 2-receptor antagonists are numbered to match the corresponding brand names.
This information applies to the following medicines:
1.  Cimetidine (sye-MET-i-deen)
2.  Famotidine (fa-MOE-ti-deen)§
3.  Nizatidine (ni-ZA-ti-deen)
4.  Ranitidine (ra-NIT-ti-deen)
‡  Generic name product may be available in the U.S.
§  Generic name product may be available in Canada
*  Not commercially available in the U.S.
†  Not commercially available in Canada

Category


Description

Histamine H 2-receptor antagonists, also known as H 2-blockers, are used to treat duodenal ulcers and prevent their return. They are also used to treat gastric ulcers and for some conditions, such as Zollinger-Ellison disease, in which the stomach produces too much acid. In over-the-counter (OTC) strengths, these medicines are used to relieve and/or prevent heartburn, acid indigestion, and sour stomach. H 2-blockers may also be used for other conditions as determined by your doctor.

H 2-blockers work by decreasing the amount of acid produced by the stomach.

They are available in the following dosage forms:



Before Using This Medicine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For H 2-blockers, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to cimetidine, famotidine, nizatidine, or ranitidine.

Pregnancy—H 2-blockers have not been studied in pregnant women. In animal studies, famotidine and ranitidine have not been shown to cause birth defects or other problems. However, one study in rats suggested that cimetidine may affect male sexual development. More studies are needed to confirm this. Also, studies in rabbits with very high doses have shown that nizatidine causes miscarriages and low birth weights. Make sure your doctor knows if you are pregnant or if you may become pregnant before taking H 2-blockers.

Breast-feeding—Cimetidine, famotidine, nizatidine, and ranitidine pass into the breast milk and may cause unwanted effects, such as decreased amount of stomach acid and increased excitement, in the nursing baby. It may be necessary for you to take another medicine or to stop breast-feeding during treatment. Be sure you have discussed the risks and benefits of the medicine with your doctor.

Children—This medicine has been tested in children and, in effective doses, has not been shown to cause different side effects or problems than it does in adults when used for short periods of time.

Older adults—Confusion and dizziness may be especially likely to occur in elderly patients, who are usually more sensitive than younger adults to the effects of H 2-blockers.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking or receiving H 2-blockers it is especially important that your health care professional know if you are taking any of the following:

Other medical problems—The presence of other medical problems may affect the use of H 2-blockers. Make sure you tell your doctor if you have any other medical problems, especially:


Proper Use of This Medicine

For patients taking the nonprescription strengths of these medicines for heartburn, acid indigestion, and sour stomach:

For patients taking the prescription strengths of these medicines for more serious problems:

It may take several days before this medicine begins to relieve stomach pain. To help relieve this pain, antacids may be taken with the H 2-blocker, unless your doctor has told you not to use them. However, you should wait one-half to one hour between taking the antacid and the H 2-blocker.

Take this medicine for the full time of treatment, even if you begin to feel better. Also, it is important that you keep your appointments with your doctor for check-ups so that your doctor will be better able to tell you when to stop taking this medicine.

For patients taking famotidine chewable tablets:

For patients taking famotidine oral disintegrating tablets:

For patients taking ranitidine effervescent granules or tablets:

Dosing—

The dose of histamine H 2-receptor antagonists (also called H 2-blockers) will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of these medicines. If your dose is different, do not change it unless your doctor tells you to do so.

The number of capsules or tablets or teaspoonfuls of solution, suspension, or syrup that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are taking the H .

Missed dose—

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store this medicine:


Precautions While Using This Medicine

Some tests may be affected by this medicine. Tell the doctor in charge that you are taking this medicine before:

Remember that certain medicines, such as aspirin, and certain foods and drinks (e.g., citrus products, carbonated drinks, etc.) irritate the stomach and may make your problem worse.

Cigarette smoking tends to decrease the effect of H 2-blockers by increasing the amount of acid produced by the stomach. This is more likely to affect the stomach's nighttime production of acid. While taking H 2-blockers, stop smoking completely, or at least do not smoke after taking the last dose of the day.

Drinking alcoholic beverages while taking an H 2-receptor antagonist has been reported to increase the blood levels of alcohol. You should consult your health care professional for guidance.

Check with your doctor if your ulcer pain continues or gets worse.


Side Effects of This Medicine

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

Not all of the side effects listed above have been reported for each of these medicines, but they have been reported for at least one of them. All of the H 2-blockers are similar, so any of the above side effects may occur with any of these medicines.

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.


Additional Information

Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although these uses are not included in product labeling, H 2-blockers are used in certain patients with the following medical conditions:

Other than the above information, there is no additional information relating to proper use, precautions, or side effects for these uses.

Revised: 05/29/2001

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