Indicated to reduce the development of drug-resistant bacteria and maintain the effectiveness of Bactrim (sulfamethoxazole and trimethoprim) tablets and other antibacterial drugs, Bactrim (sulfamethoxazole and trimethoprim) tablets should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria.

Urinary Tract Infections:

• For the treatment of urinary tract infections due to susceptible strains of the following organisms: Escherichia coli, Klebsiella species, Enterobacter species, Morganella morganii, Proteus mirabilis and Proteus vulgaris. It is recommended that initial episodes of uncomplicated urinary tract infections be treated with a single effective antibacterial agent rather than the combination.

Acute Otitis Media:

• For the treatment of acute otitis media in pediatric patients due to susceptible strains of Streptococcus pneumoniae or Haemophilus influenzae when in the judgment of the physician Sulfamethoxazole and Trimethoprim offers some advantage over the use of other antimicrobial agents. To date, there are limited data on the safety of repeated use of Sulfamethoxazole and Trimethoprim in pediatric patients under two years of age. This product is not indicated for prophylactic or prolonged administration in otitis media at any age.

Acute Exacerbations of Chronic Bronchitis in Adults:

• For the treatment of acute exacerbations of chronic bronchitis due to susceptible strains of Streptococcus pneumoniae or Haemophilus influenzae when in the judgment of the physician this combination offers some advantage over the use of a single antimicrobial agent.

Shigellosis:

• For the treatment of enteritis caused by susceptible strains of Shigella flexneri and Shigella sonnei when antibacterial therapy is indicated.

Pneumocystis jiroveci Pneumonia:

• For the treatment of documented Pneumocystis jiroveci pneumonia and for prophylaxis against P. jiroveci pneumonia in individuals who are immunosuppressed and considered to be at an increased risk of developing P. jiroveci pneumonia.

Co-administration of BACTRIM and leucovorin should be avoided with P. jiroveci pneumonia.

Traveler’s Diarrhea in Adults:

• For the treatment of traveler’s diarrhea due to susceptible strains of enterotoxigenic E. coli. 

Fatalities associated with the administration of sulfonamides, although rare, have occurred due to severe reactions, including stevens-johnson syndrome, toxic epidermal necrolysis, fulminant hepatic necrosis, agranulocytosis, aplastic anemia and other blood dyscrasias.

BACTRIM is contraindicated:

• in patients with a history of drug-induced immune thrombocytopenia with use of trimethoprim and/or sulfonamides, and in patients with documented megaloblastic anemia due to folate deficiency
• in pediatric patients less than 2 months of age
• in patients with marked hepatic damage or with severe renal insufficiency when renal function status cannot be monitored

Cough, shortness of breath, and pulmonary infiltrates are hypersensitivity reactions of the respiratory tract that have been reported in association with sulfonamide treatment.

Other severe pulmonary adverse reactions occurring within days to week of BACTRIM initiation and resulting in prolonged respiratory failure requiring mechanical ventilation or extracorporeal membrane oxygenation (ECMO), lung transplantation or death have also been reported in patients and otherwise healthy individuals treated with sulfamethoxazole and trimethoprim products.

Even treatment with recommended doses may cause hyperkalemia when trimethoprim is administered to patients with underlying disorders of potassium metabolism, with renal insufficiency, or if drugs known to induce hyperkalemia are given concomitantly. Close monitoring of serum potassium is warranted in these patients.

Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including BACTRIM, and may range in severity from mild diarrhea to fatal colitis.

Severe cases of thrombocytopenia that are fatal or life threatening have been reported.

BACTRIM should be given with caution to patients with impaired renal or hepatic function, to those with possible folate deficiency (e.g., the elderly, chronic alcoholics, patients receiving anticonvulsant therapy, patients with malabsorption syndrome, and patients in malnutrition states) and to those with severe allergies or bronchial asthma.

As with all drugs containing sulfonamides, caution is advisable in patients with porphyria or thyroid dysfunction.

Caution is recommended when Bactrim is co-administered with drugs that are substrates of CYP2C8 and 2C9 or OCT2.

In elderly patients concurrently receiving certain diuretics, primarily thiazides, an increased incidence of thrombocytopenia with purpura has been reported.

It has been reported that BACTRIM may prolong the prothrombin time in patients who are receiving the anticoagulant warfarin (a CYP2C9 substrate). This interaction should be kept in mind when BACTRIM is given to patients already on anticoagulant therapy, and the coagulation time should be reassessed.

BACTRIM may inhibit the hepatic metabolism of phenytoin (a CYP2C9 substrate). BACTRIM, given at a common clinical dosage, increased the phenytoin half-life by 39% and decreased the phenytoin metabolic clearance rate by 27%. When administering these drugs concurrently, one should be alert for possible excessive phenytoin effect.

Sulfonamides can also displace methotrexate from plasma protein binding sites and can compete with the renal transport of methotrexate, thus increasing free methotrexate concentrations.

There have been reports of marked but reversible nephrotoxicity with co-administration of BACTRIM and cyclosporine in renal transplant recipients.

Fatalities and serious adverse reactions including severe cutaneous adverse reactions (SCARs) including Stevens-Johnson syndrome, toxic epidermal necrolysis, drug reaction with eosinophilia and systemic symptoms (DRESS), acute febrile neutrophilic dermatosis (AFND), acute generalized erythematous pustulosis (AGEP); fulminant hepatic necrosis; agranulocytosis, aplastic anemia and other blood dyscrasias; acute and delayed lung injury; anaphylaxis and circulatory shock have occurred with the administration of sulfamethoxazole and trimethoprim products, including BACTRIM.

Increased digoxin blood levels can occur with concomitant BACTRIM therapy, especially in elderly patients. Serum digoxin levels should be monitored. Increased sulfamethoxazole blood levels may occur in patients who are also receiving indomethacin.

Occasional reports suggest that patients receiving pyrimethamine as malaria prophylaxis in doses exceeding 25 mg weekly may develop megaloblastic anemia if BACTRIM is prescribed.

The efficacy of tricyclic antidepressants can decrease when co-administered with BACTRIM.

BACTRIM potentiates the effect of oral hypoglycemics that are metabolized by CYP2C8 (e.g., pioglitazone, repaglinide, and rosiglitazone) or CYP2C9 (e.g., glipizide and glyburide) or eliminated renally via OCT2 (e.g., metformin). Additional monitoring of blood glucose may be warranted.

Some epidemiologic studies suggest that exposure to sulfamethoxazole/trimethoprim during pregnancy may be associated with an increased risk of congenital malformations, particularly neural tube defects, cardiovascular malformations, urinary tract defects, oral clefts, and club foot. If sulfamethoxazole/trimethoprim is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be advised of the potential hazards to the fetus.

Levels of trimethoprim/sulfamethoxazole in breast milk are approximately 2–5% of the recommended daily dose for infants over 2 months of age.

GoToSource

• Use in patients under the age of 2 months. GoToSource

• Acne. GoToSource

• Toxoplasma encephalitis. GoToSource

• Prophylactic therapy for pediatric urinary tract infections. GoToSource

• Chronic prostatitis/chronic pelvic pain syndrome. GoToSource

• Preventing implant infections in the irradiated chest wall. GoToSource

• Prevention of HIV-related opportunistic infections. GoToSource 

• Ocular toxoplasmosis. GoToSource

⚠️  Use of Trimethoprim/Sulfamethoxazole in patients with G6PD gene variation has been associated with hemolytic anemia.

Hyponatremia (low sodium level). GoToSource

Neural tube defects after use during first trimester of pregnancy. GoToSource

QT prolongation. GoToSource

Antiphospholipid antibody syndrome (disorder causing blood clot formation). GoToSource

Stevens-johnson syndrome and exfoliative dermatitis (severe skin reaction). GoToSource

Toxic epidermal necrolysis (life-threatening skin disorder). GoToSource

Acute psychosis. GoToSource

Thrombocytopenia (low blood platelet count). GoToSource

Cholestatic hepatitis (impairment of bile formation or bile flow). GoToSource

Acute kidney injury. GoToSource

Drug interaction with dilantin. GoToSource

Acute bilateral parotitis (inflammation of salivary glands). GoToSource

Interstitial lung disease. GoToSource

Hypoglycemia when used with repaglinide. GoToSource

Higher-level gait disorder and nocturnal delirium. GoToSource

Pancreatitis (inflammation of pancreas). GoToSource

Aseptic meningitis. GoToSource

Renal tubular acidosis (accumulation of acid in the body). GoToSource

Lawsuits filed for stevens-johnson syndrome and toxic epidermal necrolysis.