• Treatment of:
  • Bronchitis,
  • Shigella enteritis,
  • Otitis media,
  • Pneumocystis jiroveciipneumonia (PJP),
  • Urinary tract infections,
  • Traveler’s diarrhea.
• Prevention of PJP in patients with HIV.

Unlabeled Use:

• Biliary tract infections, osteomyelitis, burn and wound infections, chlamydial infections, endocarditis, gonorrhea, intra-abdominal infections, nocardiosis, rheumatic fever prophylaxis, sinusitis, eradication of meningococcal carriers, prophylaxis of urinary tract infections, and an alternative agent in the treatment of chancroid.
• Prevention of bacterial infections in immunosuppressed patients.

Contraindicated in:

• Hypersensitivity to sulfonamides or trimethoprim
• History of drug-induced immune thrombocytopenia due to sulfonamides or trimethoprim
• Megaloblastic anemia secondary to folate deficiency
• Severe renal impairment
• Severe hepatic impairment
• Concurrent use with dofetilide
• Lactation: Avoid breastfeeding in infants who have glucose-6–phosphate dehydrogenase (G6PD) deficiency or hyperbilirubinemia
• Pedi: Children <2 mo (can cause kernicterus).

Use Cautiously in:

• Mild or moderate renal impairment (dose ↓ required if CCr <30 mL/min)
• Mild or moderate hepatic impairment
• G6PD deficiency (↑ risk hemolysis)
• HIV (↑ incidence of adverse reactions)
• Concurrent use with other products containing propylene glycol (IV only) (↑ risk of lactic acidosis)
• OB: ↑ risk of neural tube defects, cardiovascular malformations, urinary tract defects, oral clefts, and club foot in fetus when used during pregnancy; use during pregnancy only if potential maternal benefit justifies potential fetal risk
• Lactation: Use while breastfeeding only if potential maternal benefit justifies potential risk to infant
• Geri: Appears on Beers list. Use with caution in older adults taking an angiotensin-converting enzyme inhibitor, angiotensin II receptor blocker, or angiotensin receptor/neprilysin inhibitor, and in those with a reduced CCr because of ↑ risk of hyperkalemia.

CV: hypotension.

Derm: rash, ACUTE FEBRILE NEUTROPHILIC DERMATOSIS, ACUTE GENERALIZED EXANTHEMATOUS PUSTULOSIS, DRUG REACTION WITH EOSINOPHILIA AND SYSTEMIC SYMPTOMS (DRESS), ERYTHEMA MULTIFORME, FEBRILE NEUTROPHILIC DERMATOSIS, photosensitivity, STEVENS-JOHNSON SYNDROME (SJS), TOXIC EPIDERMAL NECROLYSIS.

Endo: hypoglycemia.

F and E: hyperkalemia, hyponatremia.

GI: nausea, vomiting, cholestatic jaundice, CLOSTRIDIOIDES DIFFICILE-ASSOCIATED DIARRHEA (CDAD), diarrhea, HEPATIC NECROSIS, hepatitis, pancreatitis, stomatitis.

GU: crystalluria.

Hemat: AGRANULOCYTOSIS, APLASTIC ANEMIA, hemolytic anemia, leukopenia, megaloblastic anemia, thrombocytopenia.

Local: phlebitis at IV site.

Neuro: fatigue, hallucinations, headache, insomnia, kernicterus (neonates), mental depression.

Misc: fever, HYPERSENSITIVITY REACTIONS (INCLUDING ANAPHYLAXIS AND RESPIRATORY FAILURE).

Drug-Drug:

• May ↑dofetilide levels and the risk of QT interval prolongation with arrhythmias; concurrent use contraindicated.
• May ↑ levels and the risk of toxicity of phenytoin; closely monitor phenytoin levels.
• May ↑ levels of and the risk of bleeding from warfarin; closely monitor INR.
• May ↑ hypoglycemic effects of sulfonylureas, pioglitazone, repaglinide, and metformin.
• May ↑ toxicity of methotrexate; avoid concurrent use.
• ↑ risk of thrombocytopenia from thiazide diuretics, especially in older adults.
• May ↑ risk of nephrotoxicity associated with cyclosporine; avoid concurrent use.
• May ↑ levels and the risk of toxicity of digoxin , especially in older adults; closely monitor digoxin levels.
• Indomethacin may ↑ levels and the risk of toxicity; avoid concurrent use.
• ACE inhibitors may ↑ risk of hyperkalemia; avoid concurrent use.
• May ↓ the effects of tricyclic antidepressants.
• May ↑ risk of myelosuppression with zidovudine.
• May ↑ procainamide levels and the risk of QT interval prolongation with arrhythmias; closely monitor procainamide levels.

(Generic available)

• Tablets: 20 mg TMP/100 mg SMX; 80 mg TMP/400 mg SMX; 160 mg TMP/800 mg SMX (double-strength);
• Oral suspension (cherry, grape flavors): 40 mg TMP/200 mg SMX per 5 mL;
• Solution for injection: 16 mg TMP/80 mg SMX per mL (contains 40% propylene glycol);

Bacterial Infections

• PO, IV (Adults and Children >2 mo): Mild to moderate infections: 6–12 mg TMP/kg/day divided every 12 hr; Serious infection/PJP: 15–20 mg TMP/kg /day divided every 6–8 hr.
• PO (Adults): Urinary tract infection/chronic bronchitis: 1 double-strength tablet (160 mg TMP/800 mg SMX) every 12 hr for 10–14 days.

Urinary Tract Infection Prophylaxis

• PO, IV (Adults and Children >2 mo): 2 mg TMP/kg/dose once daily or 5 mg TMP/kg/dose twice weekly.

P. jirovecii Pneumonia Prevention

• PO (Adults): 1 double-strength tablet (160 mg TMP/800 mg SMX) once daily (may also be given 3 times weekly).
• PO (Children >1 mo): 150 mg TMP/m²/day divided every 12 hr or given as a single dose on 3 consecutive days/wk (not to exceed 320 mg TMP/1600 mg SMX per day).

Bactrim, Bactrim DS, Sulfatrim Pediatric

• Combination inhibits the metabolism of folic acid in bacteria at two different points.

• Bactericidal action against susceptible bacteria.

Spectrum:

• Active against many strains of gram-positive aerobic pathogens including:
  • Streptococcus pneumoniae,
  • Staphylococcus aureus.
• Has activity against many aerobic gram-negative pathogens, such as:
  • Enterobacter,
  • Klebsiella,
  • Morganella morganii,
  • Escherichia coli,
  • Proteus mirabilis,
  • Proteus vulgaris,
  • Shigella,
  • Haemophilus influenzae.
• Pneumocystis jirovecii.
• Not active against Pseudomonas aeruginosa.

Therapeutic Classification: anti-infectives, antiprotozoals

Pharmacologic Classification: folate antagonists, sulfonamides

Absorption: Well absorbed from the GI tract.

Distribution: Widely distributed to tissues. Crosses the blood-brain barrier.

Metabolism/Excretion: Some metabolism by the liver (20%); remainder excreted unchanged by the kidneys.

Half-life: Trimethoprim (TMP): 6–11 hr; sulfamethoxazole (SMX): 9–12 hr, both prolonged in renal failure.

Septra, Sulfatrim, Sulfatrim DS

(plasma concentrations)

• Instruct patient to take medication around the clock and to finish drug completely as directed, even if feeling well. Take missed doses as soon as remembered unless almost time for next dose. Advise patient that sharing of this medication may be dangerous.
• Instruct patient to notify health care professional if rash or fever and diarrhea develop, especially if diarrhea contains blood, mucus, or pus. Advise patient not to treat diarrhea without consulting health care professional.
• Caution patient to use sunscreen and protective clothing to prevent photosensitivity reactions.
• Advise patient to notify health care professional if skin rash, sore throat, fever, mouth sores, or unusual bleeding or bruising occurs.
• Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications.
• Instruct patient to notify health care professional if symptoms do not improve within a few days.
• Rep: May cause fetal harm. Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected, or if breastfeeding. Fetal exposure during pregnancy may lead to increased risk of congenital malformations, neural tube defects, cardiovascular malformations, urinary tract defects, oral clefts, and club foot.
• Emphasize importance of regular follow-up exams to monitor blood counts in patients on prolonged therapy.
• Home Care Issues: Instruct family or caregiver on dilution, rate, and administration of drug and proper care of IV equipment.

trye-METH-oh-prim/sul-fa-meth- OX-a-zole