Brand Name(s):

  • Bactrim®
  • Bactrim®DS
  • Septra®
  • Septra®DS
  • Septra®Grape Suspension
  • Septra®Suspension
  • Sulfatrim®Pediatric Suspension
  • Sulfatrim®Suspension

WHY is this medicine prescribed?

Co-trimoxazole is a combination of trimethoprim and sulfamethoxazole, a sulfa drug. It eliminates bacteria that cause various infections, including infections of the urinary tract, lungs (pneumonia), ears, and intestines. 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?

Co-trimoxazole comes as a tablet and a liquid to take by mouth. It usually is taken two times a day but may be taken up to four times a day for severe lung infections. Drink a full glass of water with each dose.

Shake the liquid well before each use to mix the medication evenly. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take co-trimoxazole 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 co-trimoxazole,

  • tell your doctor and pharmacist if you are allergic to co-trimoxazole, diuretics ('water pills'), oral diabetes medications, any sulfa drug, or any other drugs.
  • tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially methotrexate, phenytoin (Dilantin), warfarin (Coumadin), and vitamins.
  • tell your doctor if you have or have ever had liver or kidney disease, asthma, severe allergies, or glucose-6-phosphate dehydrogenase (G-6-PD) deficiency (an inherited blood disease).
  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking co-trimoxazole, call your doctor.
  • plan to avoid unnecessary or prolonged exposure to sunlight and to wear protective clothing, sunglasses, and sunscreen. Co-trimoxazole may make your skin sensitive to sunlight.

What SPECIAL DIETARY instructions should I follow?

Co-trimoxazole may cause an upset stomach. Take co-trimoxazole 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 the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What SIDE EFFECTS can this medicine cause?

Co-trimoxazole may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • upset stomach
  • vomiting
  • loss of appetite

If you experience any of the following symptoms, call your doctor immediately:

  • skin rash
  • itching
  • sore throat
  • fever or chills
  • mouth sores
  • unusual bruising or bleeding
  • yellowing of the skin or eyes
  • paleness
  • joint aches

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 [at Web Site] 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). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

What should I do in case of 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.

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 co-trimoxazole.

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 co-trimoxazole, 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.

AHFS® Consumer Medication Information. © Copyright, The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Last Reviewed: September 1, 2010.