H2 receptor antagonist poisoning is an overdose of a medication typically used for reducing stomach acid.

• Cimetidine
• Ranitidine
• Famotidine
• Nizatidine

Note: This list may not be all inclusive.

• Cimetidine (Tagamet)
• Ranitidine (Zantac)
• Famotidine (Pepcid)
• Nizatidine (Axid)

• Abnormal heartbeat
• Confusion
• Diarrhea
• Difficulty breathing
• Drowsiness
• Flushing
• Low blood pressure
• Nausea
• Rapid heartbeat or slow heartbeat
• Slurred speech
• Sweating
• Tremors
• Vomiting
• Walking problems

Seek immediate medical attention. DO NOT try to make the person vomit.

Determine the following information:

• Patient's age, weight, and condition
• The name of the product (ingredients and strengths if known)
• When it was swallowed
• The amount swallowed

The National Poison Control Center (1-800-222-1222) can be called from anywhere in the United States. This national hotline number will let you talk to experts in poisoning. They will give you further instructions.

This is a free and confidential service. All local poison control centers in the U.S. use this national number. You should call if you have any questions about poisoning or poison prevention. It does NOT need to be an emergency. You can call for any reason, 24 hours a day, 7 days a week.

The patient may be given the following:

• Activated charcoal
• Laxative
• Other medicines to treat symptoms

Some or all of the following procedures may be performed:

• Stomach emptying (gastric lavage)
• Artificial respiration (breathing) if necessary

Serious complications are rare.

Morgan JC. Drug-induced tremors. Lancet Neurol. 2005; 4(12): 866-76.

Feldman M, Friedman LS, Sleisenger MH, eds. Sleisenger & Fordtran’s Gastrointestinal and Liver Disease. 7th ed. Philadelphia, Pa: WB Saunders; 2002: 759.