What is cimetidine?
Cimetidine is in a group of drugs called histamine receptor antagonists. Cimetidine works by decreasing the amount of acid your stomach produces.
Cimetidine is used to treat and prevent certain types of ulcer, and to treat conditions that cause the stomach to produce too much acid. Cimetidine is also used to treat gastroesophageal reflux disease (GERD), when stomach acid backs up into the esophagus and causes heartburn.
Cimetidine may also be used for other purposes not listed in this medication guide.
Taking cimetidine may make you more susceptible to virus that causes pneumonia. You may be more likely to develop pneumonia if you have certain health problems.
Ask a doctor or pharmacist about using cimetidine if you have:
- asthma or a chronic lung disorder;
- a weak immune system;
- bone marrow suppression;
- kidney disease; or
- liver disease.
Cimetidine is in the FDA pregnancy category B. This means that it is not expected to be harmful to an unborn baby. Do not use this medication without telling your doctor if you are pregnant or plan to become pregnant during treatment.
Cimetidine passes into breast milk, and may be harmful to a nursing baby. Do not take cimetidine without telling your doctor if you are breast-feeding a baby.
Do not give this medicine to a child younger than 16 years old unless your doctor has told you to.
If you also take ketoconazole (Nizoral), take it at least 2 hours before you take cimetidine.
Avoid taking antacids unless your doctor recommends them for heartburn pain. Follow your doctor’s advice about the type of antacid to use and when to use it. You may not be able to take the antacid at the same time you take your dose of cimetidine.
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Seek emergency medical attention if you think you have used too much of this medicine. Overdose symptoms may include nausea, vomiting, diarrhea, confusion, extreme weakness, or fainting.
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.
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Stop using cimetidine and get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have any of these serious side effects:
- cough, fever, chest congestion, trouble breathing;
- red or blistering skin rash;
- jaundice (yellowing of the skin or eyes);
- easy bruising or bleeding, unusual weakness;
- feeling faint, light-headed, disoriented, or confused;
- urinating less than usual;
- irregular heartbeat; or
- a rash.
Less serious side effects may include:
- feeling dizzy, depressed, or agitated;
- breast swelling or tenderness (in men);
- joint or muscle pain;
- mild skin rash;
- headache; or
- diarrhea, nausea, or constipation.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. You may report side effects to FDA at 1-800-FDA-1088.
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Before taking this medication, tell your doctor if you are using any of the following medicines:
- a blood thinner (warfarin or Coumadin);
- phenytoin (Dilantin);
- nifedipine (Adalat);
- metronidazole (Flagyl);
- propranolol (Inderal);
- chlordiazepoxide (Librium);
- lidocaine (Xylocaine);
- diazepam (Valium);
- theophylline (Theo-Dur, Slo-Bid, Bronkodyl); or
- depression or anxiety medication such as amitriptyline (Elavil), imipramine (Tofranil), clomipramine (Anafranil), desipramine (Norpramin), nortripytyline (Aventyl).
This list is not complete and there are many other that can interact with cimetidine. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.
Tagamet, Tagamet HB, and cimetidine
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Copyright 1996-2004 Cerner Multum, Inc. Version 2.05. Revision date 8/23/04