Cimetidine Hydrochloride Injection (patient information)

# About your treatment
Your doctor has ordered cimetidine to decrease the amount of acid your stomach makes. It is used to treat and prevent ulcers and to treat other conditions in which the stomach makes too much acid. The drug will be injected into a large muscle (such as your buttock or hip); added to an intravenous fluid that will drip through a needle or catheter placed in your vein for at least 15 minutes, three or four times a day; or administered by constant infusion over 24 hours. This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
Your health care provider (doctor, nurse, or pharmacist) may measure the effectiveness and side effects of your treatment using laboratory tests and physical examinations. It is important to keep all appointments with your doctor and the laboratory. The length of treatment depends on how you respond to the medication.

# Precautions
Before administering cimetidine:
- tell your doctor and pharmacist if you are allergic to cimetidine or any other drugs.
- tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially amitriptyline (Elavil), anticoagulants ('blood thinners') such as warfarin (Coumadin), chlordiazepoxide (Librium), desipramine (Norpramin), diazepam (Valium), diuretics ('water pills'), imipramine (Tofranil), metronidazole (Flagyl), nifedipine (Adalat, Procardia), phenytoin (Dilantin), propranolol (Inderal), theophylline (Theo-Dur), triamterene (Dyrenium), and vitamins.
- tell your doctor if you have or have ever had kidney or liver disease.
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking cimetidine, call your doctor.
- remember to administer it slowly. If cimetidine is administered too rapidly, you may develop severe dizziness and faintness. Do not administer your cimetidine faster than directed. If you feel faint or dizzy, call your health care provider immediately.

# Administering your medication
Before you administer cimetidine, look at the solution closely. It should be clear and free of floating material. Gently squeeze the bag or observe the solution container to make sure there are no leaks. Do not use the solution if it is discolored, if it contains particles, or if the bag or container leaks. Use a new solution, but show the damaged one to your health care provider.
It is important that you use your medication exactly as directed. Do not stop your therapy on your own for any reason. Do not change your dosing schedule without talking to your health care provider. Your health care provider may tell you to stop your infusion if you have a mechanical problem (such as a blockage in the tubing, needle, or catheter); if you have to stop an infusion, call your health care provider immediately so your therapy can continue.

# Side effects

## Minor side effects
Cimetidine may cause side effects. Tell your health care provider if any of these symptoms are severe or do not go away:
- headache
- dizziness
- constipation
- diarrhea
- muscle pain
- drowsiness
- breast enlargement and soreness

## Severe side effects
If you experience any of the following symptoms, call your health care provider immediately:
- mental confusion
- skin rash
- itching
- hives
- difficulty breathing
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online  or by phone .

# Storing your medication
Your health care provider probably will give you a several-day supply of cimetidine at a time. If you are receiving cimetidine intravenously (in your vein), you probably will be told to store it in the refrigerator or freezer. 
Take your next dose from the refrigerator 1 hour before using it; place it in a clean, dry area to allow it to warm to room temperature. 
If you are told to store additional cimetidine in the freezer, always move a 24-hour supply to the refrigerator for the next day's use. 
Do not refreeze medications.
If you are receiving cimetidine intramuscularly (in your muscle), your health care provider will tell you how to store it properly.
Store your medication only as directed. Make sure you understand what you need to store your medication properly.
Keep your supplies in a clean, dry place when you are not using them, and keep all medications and supplies out of reach of children. Your health care provider will tell you how to throw away used needles, syringes, tubing, and containers to avoid accidental injury.

# In case of emergency/overdose
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

# Signs of infection
If you are receiving cimetidine in your vein or under your skin, you need to know the symptoms of a catheter-related infection (an infection where the needle enters your vein or skin). If you experience any of these effects near your intravenous catheter, tell your health care provider as soon as possible:
- tenderness
- warmth
- irritation
- drainage
- redness
- swelling
- pain

# Brand names
- Tagamet