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Important Note

The following 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 use of the drug is safe, appropriate, or effective for you. Consult your healthcare professional before using this drug.





Cimetidine blocks secretion of acid from the stomach. Prescription cimetidine is used to treat and prevent ulcers, to treat gastroesophageal reflux disorder (GERD), and to treat conditions associated with excessive acid secretion (e.g., Zollinger-Ellison Syndrome). Nonprescription cimetidine is used to relieve heartburn and acid indigestion.



This medication may also be used treat skin rashes caused by allergic conditions.

How To Use

This medication is taken by mouth. Take this as directed. Do not increase your dose, take this more often than prescribed or stop taking this without first consulting your doctor. If you are taking antacids in addition to this medication, stagger the doses so they are not taken at the same time. Try to space dosing of this medication and antacids by at least 2 hours.

Side Effects

Headache, fatigue, dizziness, loss of appetite, sleepiness, dry skin or dry mouth may occur as your body adjusts to the medication. Hair loss, increased sweating, anxiety, change in sex drive, breast enlargement in males and change in taste perceptions may also occur. If any of these effects continue or become bothersome, inform your doctor. Notify your doctor if you develop: skin rash, hives, irregular heartbeat, diarrhea, mental confusion, depression, difficulty walking vision changes, trouble urinating, joint or muscle pain, ringing in the ears or breathing difficulty, yellowing eyes or skin, dark urine, black tarry stools, coffee ground-appearing vomit (may suggest internal bleeding). If you notice other effects not listed above, contact your doctor or pharmacist.


Before using this medication, tell your doctor or pharmacist your medical history, especially of: heartburn combined with lightheadedness or sweating or dizziness, chest pain or shoulder/jaw pain especially with shortness of breath, pain spreading to arms or neck or shoulders, unexplained weight loss, liver or kidney problems, other stomach problems (e.g., tumors), any allergies (including drug allergies). Do not change your dose without your doctor's approval. Elderly persons may be more sensitive to the effects of this medication. This medication should be used only if clearly needed during pregnancy. Discuss the risks and benefits with your doctor. Since small amounts of this medication are found in breast milk, consult your doctor before breast-feeding.

Drug Interactions

Tell your doctor of all medications you use (both prescription and nonprescription), especially of: antacids, alcohol, heart medication, blood thinners, anti-anxiety drugs, blood pressure medications, anti-seizure drugs, medications used for diabetes, antidepressants, narcotic pain medications (e.g., codeine), azole antifungals (e.g., ketoconazole), theophylline. Cigarette smoking can affect this medication. Tell your doctor if you smoke and if you stop or start smoking while using this medication. This medication is available in both prescription and over-the-counter formulations. Do not take both at the same time. Do not start or stop any medicine without doctor or pharmacist approval.


If overdose is suspected, contact your local poison control center or emergency room immediately. Symptoms of overdose may include difficulty breathing, fast heartbeat, tremors, vomiting, restlessness, weakness, fatigue, or dizziness.


For best results, this medication is often used along with lifestyle changes such as stress-reduction programs, exercise and dietary changes. Talk to your health care professional about changes that you can benefit from. Laboratory tests may be done periodically while taking this medication to monitor results and prevent side effects.

Missed Dose

If you miss a dose, take it as soon as remembered; do not take it if it is near the time for the next dose, instead, skip the missed dose and resume your usual dosing schedule. Do not "double-up" the dose to catch up.


Store at room temperature between 59 and 86 degrees F (15 to 30 degrees C) away from heat and light. Do not store in the bathroom.