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By Medicover Hospitals / 29 Nov 2020
Home | Medicine | Sulfamethoxazole

What is Sulfamethoxazole?

Sulfamethoxazole is an antibiotic. It is used for treating bacterial infections such as infections of the urinary tract, prostatitis, and bronchitis. It is effective against both gram-negative and positive bacteria such as Listeria monocytogenes and E. Coli

Sulfamethoxazole is a bacteriostatic sulfonamide antibiotic that interacts with folic acid Sulfamethoxazole synthesis in susceptible bacteria.

Formula: C10H11N3O3S Formula:

Molar weight: 253.279 g/mol

Half-life Elimination: 10 hours

Metabolism: Glucuronidation and hepatic acetylation

Excretion: Kidney disease

Binding of protein: 70 percent

  1. Sulfamethoxazole Uses
  2. Sulfamethoxazole Side effects
  3. Precautions
  4. Sulfamethoxazole Interactions
  5. Sulfamethoxazole Over Dose
  6. Sulfamethoxazole Storage
  7. Sulfamethoxazole vs Nitrofurantoin
  8. Frequently Asked Questions
  9. Citations

Sulfamethoxazole Uses:

This medication is a combination of sulfamethoxazole and trimethoprim, two antibiotics. It is used to treat a large range of bacterial diseases (such as middle ear, urine, respiratory, and intestinal infections). A certain type of pneumonia and is also used to prevent and treat (pneumocystis-type).

  • Owing to the risk of severe side effects, this drug should not be used in children younger than 2 months of age.
  • Only certain kinds of infections are treated by this drug. For viral infections, it will not work (such as flu). Unnecessary use or misuse of any antibiotic can lead to a reduction in its efficacy.

    How to use Suspension for Sulfamethoxazole-Trimethoprim

    Before every injection, shake this drug well. Using a special measurement device/spoon, measure the dose carefully. Never use a household spoon, since the correct amount of dosage can not be given to you. Take this drug through the mouth, with a full glass of water (8 ounces / 240 milliliters) as instructed by your doctor. If an upset stomach happens, take it with food or milk. Drink plenty of fluids to lower the unlikely risk of developing kidney stones when taking this drug, unless otherwise instructed by your doctor. The dose depends on your medical condition and your treatment reaction.

    Take this antibiotic at uniformly spaced intervals of time for the best effect.Continue to take this drug until completion of the maximum amount given, even though symptoms disappear after a couple of days. Stopping it too early can allow bacteria, which can lead to infection, to continue to develop.

    Sulfamethoxazole Side Effects:

    • Nausea
    • Vomiting
    • Diarrhea
    • Muscle weakness
    • Mental/mood changes
    • Kidney problems (change in the amount of urine, blood in the urine)
    • Drowsiness
    • Signs of low blood sugar
    • Sweating
    • Shaking
    • Fast heartbeat
    • Hunger
    • Blurred vision
    • Dizziness
    • Tingling hands/feet).
    • Headache
    • Neck stiffness
    • Seizures
    • Slow/irregular heartbeat
    • Skin rash
    • Blister
    • Itching
    • Blood disorders
    • Agranulocytosis, aplastic anemia
    • Liver damage, or lung injury
    • Swelling ( face/tongue/throat)
    • Persistent sore throat
    • Fever
    • New or worsening lymph node swelling
    • Paleness
    • Joint pain
    • Aches
    • Persistent cough
    • Trouble breathing
    • Easy bleeding
    • Bruising
    • Diarrhea
    • Abdominal
    • Stomach pain
    • Cramping
    • Blood/mucus

    Incidence or side effects not known

    • Feeling Discouragement
    • Feeling of constant movement feeling sad or empty
    • Increased sensitivity of the skin to sunlight
    • Lack of feeling or emotion
    • loss of interest or pleasure
    • Nervousness
    • Redness or other discoloration of the skin
    • Feeling unreal things
    • Sensation of spinning
    • Severe sunburn
    • Trouble concentrating
    • Trouble sleeping
    • Uncaring
    • Weight loss

    The use of this medication for longer or repeated periods may result in

    • Oral thrush
    • new yeast infection
    • White patches in your mouth
    • A change in vaginal discharge
    • Or other new symptoms


    • Tell your doctor or pharmacist whether you are allergic to sulfa or trimethoprim drugs or if you have any other reactions before taking sulfamethoxazole with trimethoprim. There may be some inactive ingredients in this drug that may cause allergic reactions or other problems. For more information and details, talk to your pharmacist.
    • Tell your doctor or pharmacist your medical history before taking this medication, particularly: kidney disease, liver disease, certain blood disorders (such as porphyria, folate vitamin deficiency anemia), history of blood disorders caused by trimethoprim or sulfa drugs, vitamin deficiency (folate or folic acid), extreme allergies, asthma, decreased function of the bone marrow (bone marrow) (such as high level of potassium or decreased level of sodium in the blood).
    • This medicine can not work well with live bacterial vaccines (such as the typhoid vaccine). If your doctor advises you to, do not get any immunizations/vaccinations when taking this drug.
    • Inform your doctor or dentist of all the medications you need before having surgery (including prescription drugs, nonprescription drugs, and herbal products).
    • You can become more responsive to the sun with this drug. In the sun, limit your time. Stop booths and sun lamps for tanning. When going outside, use sunscreen and wear protective clothing. If you get sunburned or have skin blisters/redness, receive medical attention right away.
    • If you have diabetes, your blood sugar might be affected by this product. As instructed, check your blood sugar regularly and share the results with your doctor. If you have signs of low blood sugar, inform your doctor right away (see Side Effects section). Your doctor may need to change the drug, exercise regimen, or diet for your diabetes.
    • Older adults may be more prone to this drug's side effects, especially skin reactions, blood disorders, easy bleeding/bruising, and high blood levels of potassium.
    • AIDS patients may be more vulnerable to the side effects of this medication, especially skin reactions, fever, and blood disorders.
    • Due to potential damage to the unborn baby, this drug is not recommended for use during pregnancy, particularly near the expected delivery date. For more info, contact your doctor.
    • This medication is added to breast milk. While no damage to healthy infants has been documented, this medication can have adverse effects on infants who are sick or premature or have certain disorders (jaundice, high blood levels of bilirubin, G6PD deficiency). Therefore, for children with these conditions, breast-feeding is not recommended. Before breastfeeding, consult the doctor.


    Drug interactions can change the way of working of your drugs or increase the risk of serious side effects. Keep a list and share it with your doctor and pharmacist of all the medications you use (including prescription/nonprescription medicines and herbal products). Without your doctor's permission, do not start, stop, or adjust the dosage of any medication.

    Some drugs that can interact with this drug include: dofetilide, methenamine, methotrexate, 'blood thinners' (such as warfarin).

    Certain laboratory tests can interfere with this product, likely causing false test results. Make sure that the laboratory staff and all the doctors know that you are using this medication.


    If overdosed, this drug can be harmful. When someone has taken an overdose some extreme signs such as passing out or respiratory problems can occur.


    • Do not share the drug with anyone.
    • In order to monitor the progress or check for side effects, laboratory and/or medical tests (such as a lung/breathing test, blood pressure) should be conducted regularly. For more info, contact your doctor.
    • Ignore allergens/irritants which can make breathing problems worse, such as smoke, pollen, pet dander, dust, or molds.
    • Learn to use a peak flow meter, use it every day, and record worsening breathing symptoms promptly (such as yellow/red range readings, increased use of rapid-relief inhalers).

    Missed dose:

    If you are using this product on a daily basis and forget a dose, take it as soon as you recall it. If it is near the next dose, don’t take the skipped dose. Using the next dose on a regular basis. Do Not double the dose to recover the missed or forgotten dose.

    Sulfamethoxazole Storage:

    Store this medication at room temperature only and try to keep away from moisture, heat, and light. Do not freeze it. Do not store it in the bathroom or washroom.Do not flush the drug in the sink or dump it into the sink unless told to do. Disposal of this product is necessarily important when it has expired or is no longer required to you. Consult your pharmacist or local waste disposal company for more information and guidance about how to safely dispose of your product.

    Sulfamethoxazole vs Nitrofurantoin :

    Formula: C10H11N3O3S Formula: C8H6N4O5
    Molar mass: 253.279 g/mol Molar mass: 238.16 g/mol
    Antibiotic medication Antibiotic medication
    Used for treating bacterial infections such as infections of the urinary tract and bronchitis. Used to treat the infections in bladder, ear infections, and minor skin infections
    Some kind of kidney disease is treated Not effective for kidney diseases

    Frequently Asked Questions:

    Yes, sulfamethoxazole is an antibiotic used for treating bacterial infections such as infections of the urinary tract, prostatitis, and bronchitis.
    This medication is a combination of sulfamethoxazole and trimethoprim, two antibiotics. It is used to treat a large range of bacterial diseases (such as middle ear, urine, respiratory, and intestinal infections). A certain type of pneumonia is also used to prevent and treat (pneumocystis-type).
    Nausea, vomiting, headache, dizziness, weakness
    This drug is used to treat the infections of urinary tract, acute otitis media, bronchitis, shigellosis, pneumocystis pneumonia, diarrhea, methicillin-resistant Staphylococcus aureus is Bactrim (sulfamethoxazole and trimethoprim) DS (MRSA).
    Duration is 10 to 15 days. The dosage is 1 tablet (DS tablet) of 800 milligrams (mg) of sulfamethoxazole and 160 mg of trimethoprim, 2 tablets of 400 mg of sulfamethoxazole and 80 mg of trimethoprim, or else you can take 4 teaspoons or 20 milliliters (mL) of oral liquid per 12 hours for 10 to 14 days. For the treatment of bacterial infections.


  • Sulfamethoxazole, https://jamanetwork.com/journals/jamainternalmedicine/article-abstract/215162
  • Reactions of Sulfamethoxazole ,https://www.acpjournals.org/doi/abs/10.7326/0003-4819-100-4-495