What is this medicine?
CIMETIDINE (sye MET i deen) is a type of antihistamine that blocks the release of stomach acid. It is used to treat stomach or intestinal ulcers. It can relieve ulcer pain and discomfort, and the heartburn from acid reflux.
This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.
COMMON BRAND NAME(S): Acid Reducer, Major Acid Reducer, Tagamet, Tagamet HB
What should I tell my health care provider before I take this medicine?
They need to know if you have any of these conditions:
- blood in your stools (black or tarry stools) or if you have blood in your vomit
- kidney disease
- liver disease
- pain or trouble trying to swallow food
- an unusual or allergic reaction to cimetidine, other medicines, foods, dyes, or preservatives
- pregnant or trying to get pregnant
How should I use this medicine?
Take this medicine by mouth. Follow the directions on the prescription label. Swallow the tablets with a drink of water. If you only take this medicine once a day take it at bedtime. Take your doses at regular intervals. Do not take your medicine more often than directed.
Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.
Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.
NOTE: This medicine is only for you. Do not share this medicine with others.
What if I miss a dose?
If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.
What may interact with this medicine?
Do not take cimetidine if you take the following drugs:
This medicine may also interact with the following medications:
- female hormones, including contraceptive or birth control pills
- medicines for heart rhythm problems
This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.
What should I watch for while using this medicine?
Tell your doctor or health care professional if your pain does not start to get better or gets worse. You may need to take this medicine for several days before your symptoms get better. Finish the full course of tablets prescribed by your doctor or health care professional even if you feel better.
Do not take with aspirin, ibuprofen, or other antiinflammatory medicines unless directed to do so by your health care professional. These can make your condition worse.
Do not smoke cigarettes or drink alcohol. These increase irritation in your stomach and can increase the time it will take for your ulcer to heal.
If you get black, tarry stools or vomit up what looks like coffee grounds, call your doctor or health care professional right away. You may have a bleeding ulcer.
This medicine may cause a decrease in vitamin B12. You should make sure that you get enough vitamin B12 while you are taking this medicine. Discuss the foods you eat and the vitamins you take with your health care professional.
What side effects may I notice from receiving this medicine?
Side effects that you should report to your doctor or health care professional as soon as possible:
- allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
- agitation, nervousness, depression, hallucinations
- breast swelling, tenderness
- change in sex drive or performance
- dark urine
- redness, blistering, peeling or loosening of the skin, including inside the mouth
- yellowing of the eyes or skin
Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
- nausea, vomiting
This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Where should I keep my medicine?
Keep out of the reach of children.
Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Protect from light. Keep container tightly closed. Throw away any unused medicine after the expiration date.
NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.