Drug Comparisons

Histamine-2 receptor antagonists, also known as H2 blockers, are drugs that prevent or block the production of gastric (stomach) acid. These drugs are used to heal ulcers and relieve the symptoms and pain associated with gastroesophageal reflux disease (GERD). A pump in the stomach releases hydrochloric acid when stimulated by histamine. H2 blockers prevent histamine from stimulating this pump, thereby reducing the amount of acid that is released into the stomach. H2 blockers are available over-the-counter (OTC) or by prescription. OTC H2 blockers are lower doses that can be used for the prevention and relief of mild, occasional or meal-induced heartburn, acid indigestion, and sour stomach. Prescription strength H2 blockers are higher doses used for more moderate or severe forms of GERD.

Drugs in this Class
Ranitidine Tablets (Zantac 75, Zantac Tablets)
Cimetidine Tablets (Tagamet, Tagamet HB)
Ranitidine Oral Syrup (Zantac Syrup)
Nizatidine capsules (Axid AR, Axid Capsules, Nizatadine Capsules)
Ranitidine Hydrochloride Injection (Zantac Injection)
Ranitidine Effervescent Tablets or Granules (Zantac EFFERdose)
Famotidine Chewable Tablets (Pepcid AC Chewable Tablets)
Famotidine Oral Suspension (Pepcid Oral Suspension)

Summarizing the Evidence

• All of the over-the-counter (OTC) H2 blockers appear to be similar in how well they work, in dosing frequency, side effects, and drug interactions, except for cimetidine (Tagamet HB), whose drug interaction potential is greater than those of the other drugs in this class. In general, the studies examined did not make any distinctions between the available H2 blockers in regards to their effective treatment of the various acid-related gastrointestinal disorders.

• All of the prescription strength H2 blockers appear to be similar in how well they work, in dosing frequency, side effects, and drug interactions, except for cimetidine (Tagamet Oral), whose drug interaction potential is greater than those of the other drugs in this class. In general, the studies do not make any distinctions between the available H2 blockers in regards to effectiveness in the treatment of the various acid-related disorders.

• OTC and prescription strength H2 blockers are not interchangeable. OTC H2 blockers are one-half of the lowest available dose of their prescription strength counterpart. Two exceptions exists--Maximum Strength Pepcid AC and Maximum Strength Zantac are available OTC but contains prescription strength famotidine (Pepcid) and ranitidine (Zantac).

Dosing and Administration

• All H2 blockers (both OTC & prescription strength) are usually taken once or twice daily depending upon the severity and frequency of GERD symptoms. If you are self-treating your GERD symptoms with an OTC H2 blocker, you should not use any of the OTC products for more than 2 weeks without consulting a doctor.

• H2 blockers generally provide relief of symptoms longer than over the counter antacids, which provide more immediate relief. If you know you will be eating foods that tend to cause heartburn symptoms ahead of time, it is advised to take the H2 blocker at least one hour before the meal. If the heartburn cannot be predicted, it is acceptable to take the H2 blocker with antacids to provide fast, long-lasting relief. There is a combination product which consists of antacid/H2RA blocker available over the counter for this type of relief.

Generic Availability

• All prescription strength H2 blockers are available in generic formulations. All over-the-counter (OTC) H2 blockers are available in various store-branded products that are typically less expensive.

Drug Interactions

Some interactions between medications can be more severe than others. The best way for you to avoid harmful interactions is to tell your doctor and/or pharmacist what medications you are currently taking, including any over-the-counter products, vitamins, and herbals. For specific information on how the drugs interact and the severity of the interaction, please use our Drug Interactions Checker.

Side Effects

To view specific side effect information, please use our Side Effect Checker.

Additional Information

References:

1. Berardi RR, Kroon L, McDermott JH and Newton GD. Handbook of Nonprescription Drugs. 15th edition. Acid-Peptic Products. American Pharmaceutical Association; Washington DC. 2006.

2. Berardi RR, Welage LS. Peptic Ulcer Disease. In: Pharmacotherapy A Pathophysiologic Approach. 6th ed. Dipiro JT, Talbert RL, Yee GC et al. (eds). McGraw-Hill. New York. 2005. pg. 629-648.

3. Drugdex Database. In: Thomson-Micromedex. Greenwood Village, CO. 2006.

4. Drug Facts and Comparisons. Wolters Kluwer Health. St. Louis, MO; 2007.

5. Knodel LC, ed. Nonprescription Products: Formulations and Features '98-99. Acid-Peptic Products. American Pharmaceutical Association; Washington DC. 1998. pg: 162.

6. Behar J, Brand DL, Brown FC et al. Cimetidine in the treatment of symptomatic gastroesophageal reflux: a double blind controlled trial. Gastroenterology. 1978;74(2 Pt 2):441-8.

7. Robinsen M, Decktor DL, Stone RC et al. Famotidine (20 mg) b.d. relieves gastrooesophageal reflux symptoms in patients without erosive oesophagitis. Famotidine/GERD Investigation Group. Aliment Pharmacol Ther. 1991;5(6):631-43.

8. Cloud ML, Offen WW, Robinson M. Nizatidine versus placebo in gastro-oesophageal reflux disease: a 12-week, multicentre, randomised, double-blind study. Br J Clin Pract Suppl. 1994;76:3-10.

9. Hine KR, Holmes GKT, Melikian V et al. Ranitidine in reflux oesophagitis. Digestion. 1984;29:119-123.

10. Kar P, Gurtoo A, Jain SK et al. Ranitidine versus placebo: a double-blind trial in the management of reflux esophagitis. Curr Ther Res. 1990;47:731-734.

11. Williams DB, Schade RR. Gastroesophageal reflux disease. In DiPiro JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM, editors. Pharmacotherapy: A Pathophysiologic Approach. 6th ed. New York: McGraw-Hill; 2005: 613-28.

12. DeVault KR. Castell DO. Updatedguideliens for the treatment of gastroesophageal reflux disease. Am J Gastroenterol 2005;100:190-200:190Available from URL: http://www.gi.org/physicians/guidelines/GERDTreatment.pdf. Accessed March 2008.

13. Tran T. Lowry AM. El-Serag HB. Meta-Analysis: the efficacy of over-the-counter gastro-esophageal reflux disease therapies. Aliment Pharmacol Ther. 2007 Jan 15;25(2):143-53. Available from URL: http://web.ebscohost.com.stlcopisa.stlcop.edu/ehost/pdf?vid=2&hid=116&sid=a8c88bc3-d398-4f70-b4e9-43b0c841c18f%40sessionmgr109. Accessed March 2008.

Last Updated: March 2008
This content was created by members of the DrugDigest team of experts and is solely under DrugDigest's editorial control.

Note: The above information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist, or other healthcare professional. It should not be construed to indicate that the use of the product is safe, appropriate, or effective for you. Consult your healthcare professional before taking any medication.