Why is this medicine prescribed?
Trimethoprim eliminates bacteria that cause urinary tract infections. It is used in combination with other drugs to treat certain types of pneumonia. It also is used to treat traveler's diarrhea. Antibiotics will not work for colds, flu, or other viral infections.
This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
How should this medicine be used?
Trimethoprim comes as a tablet to take by mouth. It usually is taken one or two times a day. Trimethoprim may be taken with or without food. Follow the directions on your prescription label carefully, and ask your pharmacist or doctor to explain any part you do not understand. Take trimethoprim exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
What special precautions should I follow?
Before taking trimethoprim,
- tell your doctor and pharmacist if you are allergic to trimethoprim, sulfa drugs, diuretics ('water pills', oral diabetes medications, or any other drugs.
- tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially phenytoin (Dilantin) and vitamins.
- tell your doctor if you have or have ever had anemia or liver or kidney disease.
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking trimethoprim, call your doctor immediately.
What special dietary instructions should I follow?
Take trimethoprim on an empty stomach, 1 hour before or 2 hours after meals. However, if you experience nausea, you may take trimethoprim with food.
What should I do if I forget to take a dose?
Take the missed dose as soon as you remember it. However, if it is almost time for your next dose, skip the missed dose and continue your dosing schedule. Do not take a double dose to make up for a missed one.
What should I do in case of overdose?
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help . If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.
What side effects can this medicine cause?
Trimethoprim may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- upset stomach
If you experience any of the following symptoms, call your doctor immediately:
- rash (hives)
- difficulty breathing or swallowing
- sore throat
- fever or chills
- mouth sores
- unusual bruising or bleeding
- yellowing of the skin or eyes
- joint aches
- bluish-colored fingernails, lips, or skin
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 ( http://www.fda.gov/Safety/MedWatch ) or by phone (1-800-332-1088).
What should I know about storage and disposal of this medication?
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).
It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org
Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website ( http://goo.gl/c4Rm4p ) for more information if you do not have access to a take-back program.
What other information should I know?
Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to trimethoprim.
Do not let anyone else take your medication. Your prescription is probably not refillable. If you still have symptoms of infection after you finish the trimethoprim, call your doctor.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.