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Bactrim Side Effects

Generic Name: sulfamethoxazole / trimethoprim

Note: This page contains information about the side effects of sulfamethoxazole / trimethoprim. Some of the dosage forms included on this document may not apply to the brand name Bactrim.

For the Consumer

Applies to sulfamethoxazole / trimethoprim: oral suspension, oral tablet

Other dosage forms:

In addition to its needed effects, some unwanted effects may be caused by sulfamethoxazole / trimethoprim. In the event that any of these side effects do occur, they may require medical attention.

Major Side Effects

You should check with your doctor immediately if any of these side effects occur when taking sulfamethoxazole / trimethoprim:

Rare
  • Abdominal or stomach pain
  • black, tarry stools
  • blistering, peeling, or loosening of the skin
  • changes in skin color
  • chest pain
  • chills
  • cough or hoarseness
  • dark urine
  • diarrhea
  • dizziness
  • fever with or without chills
  • general feeling of tiredness or weakness
  • headache
  • itching
  • joint or muscle pain
  • light-colored stools
  • loss of appetite
  • lower back or side pain
  • nausea
  • pain, tenderness, or swelling of the foot or leg
  • painful or difficult urination
  • pale skin
  • rash
  • red skin lesions, often with a purple center
  • red, irritated eyes
  • shortness of breath
  • sore throat
  • sores, ulcers, or white spots in the mouth or on the lips
  • swollen or painful glands
  • tightness in the chest
  • unpleasant breath odor
  • unusual bleeding or bruising
  • vomiting of blood
  • wheezing
  • yellow eyes or skin
Incidence not known:
  • Abdominal or stomach tenderness
  • back, leg, or stomach pains
  • bleeding gums
  • blindness or vision changes
  • blisters, hives, or itching
  • bloating
  • blood in the urine or stools
  • bluish-colored lips, fingernails, or palms
  • burning, crawling, itching, numbness, painful, prickling, "pins and needles", or tingling feelings
  • burning of the face or mouth
  • chest pain
  • cloudy urine
  • confusion
  • constipation
  • continuing ringing or buzzing or other unexplained noise in the ears
  • convulsions
  • cracks in the skin
  • decreased frequency or amount of urine
  • diarrhea, watery and severe, which may also be bloody
  • difficulty with breathing
  • difficulty with swallowing
  • fainting spells
  • general body swelling
  • general feeling of discomfort or illness
  • hair loss
  • hearing loss
  • hives
  • increased thirst
  • indigestion
  • irregular heartbeat
  • large, flat, blue, or purplish patches in the skin
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • loss of heat from the body
  • muscle or joint pain
  • nosebleeds
  • not able to pass urine
  • numbness or tingling in the hands, feet, or lips
  • pain or burning while urinating
  • pinpoint red spots on the skin
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • raised red swellings on the skin, the buttocks, legs, or ankles
  • redness of the white part of the eyes
  • redness, swelling, or soreness of the tongue
  • sores, ulcers, or white spots on the lips or in the mouth
  • soreness of the muscles
  • stiff neck or back
  • swelling of the face, hands, legs, and feet
  • unsteadiness, trembling, or other problems with muscle control or coordination
  • unusual weight loss
  • weakness in the hands or feet
  • weakness or heaviness of the legs
  • weight gain

Minor Side Effects

Some of the side effects that can occur with sulfamethoxazole / trimethoprim may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common:
  • Passing of gas
Incidence not known:
  • Discouragement
  • feeling of constant movement of self or surroundings
  • feeling sad or empty
  • increased sensitivity of the skin to sunlight
  • irritability
  • lack of feeling or emotion
  • loss of interest or pleasure
  • nervousness
  • redness or other discoloration of the skin
  • seeing, hearing, or feeling things that are not there
  • sensation of spinning
  • severe sunburn
  • trouble concentrating
  • trouble sleeping
  • uncaring
  • weight loss

For Healthcare Professionals

Applies to sulfamethoxazole / trimethoprim: intravenous solution, oral suspension, oral tablet

Cardiovascular

Rare (0.01% to 0.1%): Thrombophlebitis
Very rare (less than 0.01%): Polyarteritis nodosa, syncope
Postmarketing reports: QT prolongation resulting in ventricular tachycardia and torsade de pointes[Ref]

Dermatologic

Common (1% to 10%): Skin rash, urticaria
Very rare (less than 0.01%): Photosensitivity, exfoliative dermatitis, fixed drug eruption, erythema multiforme, erythema nodosum, Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis, bullous dermatitis, purpura, angioedema
Frequency not reported: Pruritus[Ref]

Gastrointestinal

Common (1% to 10%): Diarrhea, nausea, vomiting, anorexia
Very rare (less than 0.01%): Constipation, glossitis, stomatitis, pseudomembranous colitis, pancreatitis, abdominal pain
Frequency not reported: Sore mouth, moniliasis[Ref]

Hematologic

Very rare (less than 0.01%): Leucopenia, neutropenia, thrombocytopenia, pancytopenia, bone marrow depression, agranulocytosis, aplastic anemia, hemolytic anemia, eosinophilia, purpura, hemolysis
Frequency not reported: Megaloblastic anemia, methemoglobinemia, hypoprothrombinemia, granulocytopenia[Ref]

Hepatic

Rare (0.01% to 0.1%): Jaundice
Very rare (less than 0.01%): Hepatitis (including cholestatic jaundice and hepatic necrosis), disturbance in liver enzymes, elevated serum transaminases, elevated bilirubin[Ref]

Hypersensitivity

Very rare (less than 0.01%): Hypersensitivity, anaphylaxis, anaphylactoid reaction drug fever, chills, allergic vasculitis resembling Henoch-Schonlein purpura
Frequency not reported: Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), anaphylaxis, allergic myocarditis, erythema multiforme, exfoliative dermatitis, angioedema, serum sickness-like syndrome, generalized allergic reactions, generalized skin eruptions, conjunctival and scleral injection, photosensitivity, pruritus, urticaria, rash, periarteritis nodosa, systemic lupus erythematosus (SLE)[Ref]

Immunologic

Common (1% to 10%): Monilial overgrowth[Ref]

Local

Rare (less than 0.1%): Local reaction, pain, slight irritation[Ref]

Metabolic

Very common (10% or more): Hyperkalemia (particularly in the elderly and in HIV patients)
Very rare (less than 0.01%): Hypoglycemia, hyponatremia, metabolic acidosis[Ref]

Musculoskeletal

Rare (less than 0.1%): Rhabdomyolysis (mainly in AIDS patients)
Frequency not reported: Arthralgia, myalgia[Ref]

Nervous system

Very common (10% or more): Headache
Very rare (less than 0.01%): Aseptic meningitis (rapidly reversible on withdrawal of therapy but can reoccur on rechallenge), convulsions, peripheral neuritis, ataxia, vertigo, dizziness, tremor, lethargy, paresthesia, convulsions, peripheral neuritis, tinnitus[Ref]

Ocular

Very rare (less than 0.01%): Uveitis[Ref]

Psychiatric

Very rare (less than 0.01%): Depression, hallucination, confusional state, agitation, anxiety, abnormal behavior, insomnia, nightmares[Ref]

Renal

Very rare (less than 0.01%): Renal tubular acidosis, Impaired renal function (sometimes reported as renal failure), hematuria
Frequency not reported: Serum creatinine increased, blood urea nitrogen increased
Postmarketing reports:
Frequency not reported: Renal failure, interstitial nephritis, elevated BUN and serum creatinine, toxic nephrosis with oliguria and anuria, tubular necrosis, crystalluria, aggravation of renal disease, azotemia, hyperkalemic renal tubular acidosis, overestimations of normal creatinine values[Ref]

Respiratory

Very rare (less than 0.01%): Cough, dyspnea, lung infiltration, shortness of breath, wheezing, epistaxis[Ref]

References

1. Cerner Multum, Inc. "Australian Product Information." O 0

2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

3. "Product Information. Sulfamethoxazole-Trimethoprim (sulfamethoxazole-trimethoprim)." SICOR Pharmaceuticals Inc, Irvine, CA.

Not all side effects for Bactrim may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.

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