Acid Reducer (cimetidine) Oral Warnings
Acid Reducer (cimetidine) Oral Uses
Cimetidine is used to treat ulcers of the stomach and intestines and prevent them from coming back after they have healed. This medication is also used to treat certain stomach and throat (esophagus) problems caused by too much stomach acid (e.g., Zollinger-Ellison syndrome, erosive esophagitis) or a backward flow of stomach acid into the esophagus (acid reflux disease/GERD). Decreasing extra stomach acid can help relieve symptoms such as stomach pain, heartburn, difficulty swallowing, persistent cough, and trouble sleeping. It can also prevent serious acid damage to your digestive system (e.g., ulcers, cancer of the esophagus).
Cimetidine belongs to a class of drugs commonly called H2 blockers. It works by reducing the amount of acid in your stomach.
This medication is also available without a prescription. It is used to treat occasional heartburn caused by too much acid in the stomach (also called acid indigestion or sour stomach). It is also used to prevent heartburn and acid indigestion caused by certain foods and beverages. If you are taking this medication for self-treatment, it is important to read the manufacturer's package instructions carefully so you know when to consult your doctor or pharmacist. (See also Precautions.)How to use Acid Reducer (cimetidine) Oral
Take this medication by mouth with or without food as directed by your doctor.
The dosage and length of treatment are based on your medical condition and response to therapy. Follow your doctor's instructions carefully. If you are also taking antacids to relieve stomach pain as recommended by your doctor, separate them from this medication by at least 1 hour.
Take this medication regularly as prescribed in order to get the most benefit from it. To help you remember, take it at the same time(s) each day. Do not increase your dose or take it more often than directed. Continue to take this medication for the prescribed length of treatment even if you are feeling better. Stopping treatment too early may delay the healing process.
If you are using nonprescription cimetidine for self-treatment of acid indigestion or heartburn, take 1 tablet by mouth with a glass of water as needed. To prevent heartburn, take 1 tablet by mouth with a glass of water right before or up to 30 minutes before eating food or drinking beverages that cause heartburn. Do not take more than 2 tablets in 24 hours unless directed by your doctor. Do not take for more than 14 days in a row without talking with your doctor.
Inform your doctor if your symptoms do not improve or if they worsen.
Acid Reducer (cimetidine) Oral Side Effects
If your doctor has directed you to use this medication, remember that he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor immediately if any of these unlikely but serious side effects occur: mental/mood changes (e.g., agitation, confusion, depression, hallucinations), trouble urinating, muscle/joint pain, breast swelling/soreness in males, decreased sexual ability (with very high doses of this medication).
Tell your doctor immediately if any of these rare but very serious side effects occur: easy bruising/bleeding, signs of infection (e.g., fever, persistent sore throat, cough, trouble breathing), fast/slow/irregular heartbeat, unusual tiredness, persistent nausea/vomiting, severe stomach/abdominal pain, dark urine, yellowing eyes/skin, change in the amount of urine.
A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction include: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Acid Reducer (cimetidine) Oral Precautions
Before taking cimetidine, tell your doctor or pharmacist if you are allergic to it; or to other H2 blockers (e.g., famotidine, nizatidine, ranitidine); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: immune system problems, kidney problems, liver problems, certain lung diseases (chronic obstructive pulmonary disease-COPD), diabetes, other stomach problems (e.g., tumors).
Before taking non-prescription cimetidine for self-treatment, talk with your doctor or pharmacist first if you have any of the following symptoms. These may be signs of a more serious condition. Consult your doctor or pharmacist immediately if you have: difficulty/pain with swallowing food, persistent nausea/vomiting, bloody vomit, vomit that looks like coffee grounds, bloody/black stools, frequent chest pain, persistent stomach pain, heartburn for more than 3 months, trouble breathing with heartburn.
If you are prescribed cimetidine or are considering non-prescription cimetidine for self-treatment, tell your doctor immediately if you have any of these other symptoms that may actually be signs of a more serious condition: heartburn combined with lightheadedness/sweating/dizziness, chest/shoulder/jaw pain (especially with trouble breathing), pain spreading to arms/neck/shoulders, unexplained weight loss.
This drug may make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.
Do not use this medication to treat children younger than 12 unless directed by the doctor.
Kidney function declines as you grow older. This medication is removed by the kidneys. Therefore, the elderly may be at greater risk for side effects while using this drug, especially confusion and lung infection (pneumonia).
Cimetidine should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor.
Cimetidine passes into breast milk. Consult your doctor before breast-feeding.
Acid Reducer (cimetidine) Oral Interactions
See also How to Use section.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
If you are currently using any of these medications listed above, tell your doctor or pharmacist before starting cimetidine.
Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: artemether, clopidogrel, carmustine, lumefantrine, metformin, moclobemide, moricizine, procainamide, quinidine, silver sulfadiazine, drugs removed from your body by certain liver enzymes (such as lidocaine, metoprolol, propranolol, tacrine, warfarin, zaleplon, anti-seizure drugs including carbamazepine and phenytoin, benzodiazepines including diazepam, calcium channel blockers including diltiazem, narcotic analgesics including codeine, tricyclic antidepressants including amitriptyline, theophylline and related drugs).
Since cimetidine reduces the amount of acid in your stomach, it may also change the absorption of certain medications and affect how they work. Some examples of affected drugs include atazanavir, dasatinib, delavirdine, certain azole antifungals (such as itraconazole, ketoconazole), among others. Ask your doctor or pharmacist if any of the medications you take are affected by cimetidine and how to manage this interaction.
Check the labels on all your medicines because they may contain nonsteroidal anti-inflammatory drugs (NSAIDs such as aspirin, ibuprofen, naproxen) that may cause stomach irritation/ulcers. Ask your pharmacist about the safe use of those products. Low-dose aspirin should be continued if prescribed by your doctor for specific medical reasons such as heart attack or stroke prevention (usually at dosages of 81-325 milligrams per day). Consult your doctor or pharmacist for more details.
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 and similar H2 blockers (e.g., famotidine, nizatidine, ranitidine) are available both with and without a prescription. Do not take them at the same time.
Acid Reducer (cimetidine) Oral Overdose
If overdose is suspected, contact a poison control center or emergency room immediately. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include mental/mood changes, slurred speech, difficulty awakening.NOTES:
Do not share this medication with others.
Lifestyle changes such as stress reduction programs, stopping smoking, limiting alcohol, and diet changes (e.g., avoiding caffeine and spicy foods) may increase the effectiveness of this medication. Talk to your doctor or pharmacist about lifestyle changes that might benefit you.
Laboratory and/or medical tests may be performed to monitor your progress or check for side effects. Consult your doctor for more details.MISSED DOSE:
If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.STORAGE:
Store in a tightly closed container at room temperature between 59-86 degrees F (15-30 degrees C) away from moisture and light. Do not store in the bathroom. Keep all medicines away from children and pets.
Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.
Information last revised March 2013. Copyright(c) 2013 First Databank, Inc.