What is the most important information I should know about cimetidine?

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

What is cimetidine?

Cimetidine is a stomach acid reducer that is used to treat and prevent certain types of stomach ulcer. Cimetidine is also used to treat gastroesophageal reflux disease (GERD), when stomach acid backs up into the esophagus and causes heartburn.

Over-the-counter (nonprescription) cimetidine is used to treat heartburn with sour stomach and acid indigestion, or to prevent these conditions when caused by certain foods or beverages.

Cimetidine may also be used for purposes not listed in this medication guide.

What should I discuss with my healthcare provider before taking cimetidine?

Heartburn can mimic early symptoms of a heart attack. Get emergency medical help if you have chest pain that spreads to your jaw or shoulder and you feel anxious or light-headed.

Ask a doctor or pharmacist if cimetidine is safe to use if you have:

• stomach pain, nausea, and vomiting;
• trouble swallowing;
• frequent chest pain;
• heartburn with wheezing;
• unexplained weight loss;
• heartburn lasting longer than 3 months; or
• liver or kidney disease.

Ask a doctor before using this medicine if you are pregnant.

Do not give this medicine to a child without medical advice.

How should I take cimetidine?

Use exactly as directed on the label, or as prescribed by your doctor.

Cimetidine is usually taken with meals or at bedtime.

To prevent heartburn from foods or beverages, take cimetidine within 30 minutes before eating or drinking.

Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

Your ulcer may take longer to heal if you smoke cigarettes.

Do not take over-the-counter cimetidine for longer than 14 days without your doctor's advice.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

What should I avoid while taking cimetidine?

Avoid taking other medications within 2 hours before or 2 hours after you take cimetidine. Cimetidine can make it harder for your body to absorb certain medicines you take by mouth.

Ask your doctor before using other stomach acid reducers or antacids, and use only the type your doctor recommends.

What are the possible side effects of cimetidine?

• pain when swallowing;
• bloody or tarry stools, cough with bloody mucus or vomit that looks like coffee grounds;
• changes in mood, anxiety, agitation;
• confusion, hallucinations; or
• breast swelling or tenderness.

Serious side effects may be more likely in older adults and those who are ill or debilitated.

Common side effects may include:

• headache; or
• diarrhea.

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.

What other drugs will affect cimetidine?

Ask a doctor or pharmacist before using cimetidine with any other medications, especially:

• ketoconazole;
• phenytoin;
• theophylline;
• an antidepressant; or
• a blood thinner --warfarin, Coumadin, Jantoven;
• heart or blood pressure medicine --nifedipine, propranolol; or
• a sedative --chlordiazepoxide, diazepam.

This list is not complete and many other drugs may affect cimetidine, or be made less effective when taken at the same time as cimetidine. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Where can I get more information?

Your pharmacist can provide more information about cimetidine.