This medication is a combination of two antibiotics used to treat a wide variety of bacterial infections (e.g., middle ear, urine, respiratory and intestinal infections). It is also used to prevent and treat a certain type of pneumonia (pneumocystis-type).

This medication should not be used in children less than 2 months of age due to the risk of serious side effects.

This medication treats only certain types of infections. It will not work for viral infections (e.g., flu). Unnecessary use or misuse of any antibiotic can lead to its decreased effectiveness.

Take this medication by mouth with a full glass of water (8 ounces or 240 milliliters), or as directed by your doctor. If stomach upset occurs, take with food or milk. Drink plenty of fluids while taking this medication to prevent unlikely kidney stones from forming, unless your doctor advises you otherwise. Dosage is based on your medical condition and response to therapy.

Antibiotics work best when the amount of medicine in your body is kept at a constant level. Therefore, take this drug at evenly spaced intervals.

Continue to take this medication until the full-prescribed amount is finished, even if symptoms disappear after a few days. Stopping it too early may allow bacteria to continue to grow, which may result in a relapse of the infection.

Inform your doctor if your condition persists or worsens.

Nausea, vomiting, diarrhea, loss of appetite, or headache may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because 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: muscle weakness, mental/mood changes, new lump/growth in the neck (goiter), signs of low blood sugar (e.g., shaking, dizziness, blurred vision, unusual hunger).

Tell your doctor immediately if any of these highly unlikely but very serious side effects occur: blood in the urine, change in the amount of urine.

Seek immediate medical attention if any of these highly unlikely but very serious side effects occur: confusion, persistent headache, neck stiffness, seizures.

This medication may rarely cause serious (possibly fatal) allergic reactions and other side effects such as a severe peeling skin rash (e.g., Stevens-Johnson syndrome), blood disorders (e.g., agranulocytosis, aplastic anemia), liver damage, or lung injury. If you notice any of the following, seek immediate medical attention: skin rash/blisters, itching/swelling (especially of the face/tongue/throat), persistent sore throat or fever, paleness, joint pain/aches, persistent cough, trouble breathing, easy bleeding/bruising, yellowing eyes or skin, persistent nausea/vomiting, unusual fatigue, dark urine.

This medication may rarely cause a severe intestinal condition (Clostridium difficile-associated diarrhea) due to a resistant bacteria. This condition may occur while receiving therapy or even weeks to months after treatment has stopped. Do not use anti-diarrhea products or narcotic pain medications if you have the following symptoms because these products may make them worse. Tell your doctor immediately if you develop: persistent diarrhea, abdominal or stomach pain/cramping, or blood/mucus in your stool.

Use of this medication for prolonged or repeated periods may result in oral thrush or a new vaginal yeast infection (oral or vaginal fungal infection). Contact your doctor if you notice white patches in your mouth, a change in vaginal discharge or other new symptoms.

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.

Before taking sulfamethoxazole with trimethoprim, tell your doctor or pharmacist if you are allergic to sulfa medications or trimethoprim; or if you have any other allergies.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: a certain blood disorder (anemia due to folate vitamin deficiency), a certain metabolic disorder (porphyria), severe kidney disease, severe liver disease.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: alcohol use, anti-seizure medication use, severe allergies, asthma, decreased bone marrow function (bone marrow suppression), diabetes, a certain other metabolic disorder (G6PD deficiency), certain intestinal conditions (e.g., malabsorption), kidney disease, liver disease.

This medication may make you more sensitive to the sun. Avoid prolonged sun exposure, tanning booths or sunlamps. Use a sunscreen and wear protective clothing when outdoors.

Kidney function declines as you grow older. This medication is removed by the kidneys. Therefore, older adults may be more sensitive to the side effects of this drug, especially skin reactions, blood disorders, easy bleeding/bruising, and a high potassium blood level.

Patients with AIDS may be more sensitive to the side effects of the drug, especially skin reactions, fever, and blood disorders.

This medication should be used only when clearly needed during pregnancy. This medication should not be used near the expected delivery date because of possible harm to the unborn baby. Discuss the risks and benefits with your doctor.

This drug passes into breast milk. While there have been no reports of harm to healthy infants, this drug may have undesirable effects on infants who are ill or premature or have certain disorders (jaundice, high blood levels of bilirubin, G6PD deficiency). Therefore, breast-feeding is not recommended in infants with these conditions. Consult your doctor before breast-feeding any infant.

Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with them first.

This drug should not be used with the following medications because very serious interactions may occur: dofetilide, methenamine.

If you are currently using any of these medications tell your doctor or pharmacist before starting sulfamethoxazole with trimethoprim.

Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: certain anti-diabetic medications (e.g., glipizide, glyburide, tolbutamide), "blood thinners" (e.g., warfarin), cyclosporine, dapsone, digoxin, hydantoins (e.g., phenytoin), live vaccines, methotrexate, oral PABA, procainamide, pyrimethamine, tricyclic antidepressants (e.g., amitriptyline).

This medication may decrease the effectiveness of combination-type birth control pills. This can result in pregnancy. You may need to use an additional form of reliable birth control while using this medication. Consult your doctor or pharmacist for details.

This product can affect the results of certain lab tests. Make sure laboratory personnel and your doctors know you use this drug.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US national poison hotline at 1-800-222-1222. Canadian residents should call their local poison control center directly. Symptoms of overdose may include: severe nausea/vomiting/diarrhea, severe dizziness or drowsiness, mental/mood changes.

Do not share this medication with others.

This medication has been prescribed for your current condition only. Do not use it later for another infection unless told to do so by your doctor. A different medication may be necessary in those cases.

If using this medication for an extended period, laboratory and/or medical tests (e.g., complete blood count, kidney function tests, potassium blood level, cultures) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

If you miss a dose, use 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.

Store the US product at room temperature between 59-77 degrees F (15-25 degrees C) away from light and moisture. Do not store in the bathroom.

Store the Canadian product at room temperature between 59-86 degrees F (15-30 degrees C) away from light and moisture. 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 January 2009 Copyright(c) 2009 First DataBank, Inc.