March 27, 2015

Drug Factsheets

 Health Home >> Medications 


(trimethoprim - sulfamethoxazole)

DIN (Drug Identification Number)


What side effects are possible with Apo-Sulfatrim?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • diarrhea
  • dizziness
  • dry mouth
  • headache
  • loss of appetite
  • mouth sores or swelling of the tongue
  • nausea or vomiting
  • tiredness

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • increased sensitivity of skin to sunlight

Check with your doctor immediately if any of the following side effects occur:

  • aching of joints and muscles
  • difficulty swallowing
  • itching
  • pale skin
  • redness, blistering, peeling, or loosening of skin
  • skin rash
  • sore throat and fever
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • yellow eyes or skin

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • abdominal or stomach cramps and pain (severe)
  • abdominal or stomach tenderness
  • anxiety
  • blood in urine
  • bluish fingernails, lips, or skin
  • confusion
  • depression
  • diarrhea (watery and severe; may also be bloody)
  • difficulty breathing
  • drowsiness
  • fever
  • general feeling of illness or fatigue
  • greatly increased or decreased frequency of urination or amount of urine
  • hallucinations
  • headache (severe)
  • increased thirst
  • lower back pain
  • muscle pain or weakness
  • nausea
  • nervousness
  • pain or burning at site of injection
  • pain or burning while urinating
  • seizures (convulsions)
  • stiff neck or back
  • swelling of front part of neck

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for Apo-Sulfatrim?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Drowsiness/reduced alertness: Trimethoprim - sulfamethoxazole may cause some people to become dizzy. Determine your response to this medication before engaging in potentially dangerous activities such as driving or operating machinery.

Medical conditions: If you have liver or kidney damage, urinary obstruction, blood disorders, allergies, or bronchial asthma, discuss with your doctor the benefits and risks of this medication.

Symptoms such as rash, sore throat, fever, pallor, difficulty breathing, or jaundice (yellowing of eyes or skin) may be early indications of rare but severe reactions. Anyone experiencing these symptoms after starting this medication should contact their doctor immediately.

Other infections: The use of antibiotics may occasionally result in organisms not killed by the antibiotic to overgrow, resulting in conditions such as yeast infections. Women may prevent yeast infections by eating yogurt daily while taking this antibiotic.

Sensitivity to sunlight: This medication may increase the sensitivity of the skin to sunlight, increasing the risk of sunburn. If you notice any unusual skin rash or peeling, contact your doctor immediately.

Pregnancy: This medication should not be used during pregnancy unless, in the opinion of your doctor, the benefits outweighs the risks. Pregnant women who take this medication often take supplemental folic acid.

Breast-feeding: Both trimethoprim and sulfamethoxazole pass into breast milk. Although a breast-feeding infant would only take in a small amount of the medication, nursing women should speak to their doctor about the benefits and risks of using this medication.

Children: This medication is not recommended for children younger than 2 months of age.

What other drugs could interact with Apo-Sulfatrim?

There may be an interaction between trimethoprim - sulfamethoxazole and any of the following:

  • alcohol
  • amantadine
  • cyclosporine
  • dapsone
  • digoxin
  • diuretics (water pills)
  • folic acid
  • methotrexate
  • phenytoin
  • procainamide
  • pyrimethamine
  • sulfonylureas (e.g., chlorpropamide)
  • warfarin
  • zidovudine

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Previous | 1 | 2 | 

Did you find what you were looking for on our website? Please let us know.


The contents of this site are for informational purposes only and are meant to be discussed with your physician or other qualified health care professional before being acted on. Never disregard any advice given to you by your doctor or other qualified health care professional. Always seek the advice of a physician or other licensed health care professional regarding any questions you have about your medical condition(s) and treatment(s). This site is not a substitute for medical advice.

© 1996 - 2015 MediResource Inc. - MediResource reaches millions of Canadians each year.