Trimethoprim-Sulfamethoxazole DS
(Redirected from Trim/sulfa)
General
- Type: Sulfonamide
- Dosage Forms: 160/800; 40mg TMP/5mL
- Common Trade Names: Bactrim DS
- Abbreviations: TMP-SMX, TMP-SMZ
Adult Dosing
General
- 1 tab (160mg TMP) PO Q12h
PCP Prophylaxis
- 80-160mg TMP PO daily
PCP Treatment
- 15-20mg/kg/day TMP PO divided q6-8h x 21 days
Pediatric Dosing
General (>2mo)
- Mild-mod infection
- 4-5mg/kg TMP PO q12hr
- Severe infection
- 15-20mg/kg/dy TMP PO divided q6-8h
Special Populations
- Pregnancy: D
- Lactation: ?
- Renal (Adult & Pediatric)
- CrCl 15-30: Decrease dose by 50%
- CrCl <15: Avoid use
- Hemodialysis: Give supplement
- Peritoneal Dialysis: No supplement
- Hepatic (Adult & Pediatric)[1]
- Mild-mod impairment: Caution advised
- Significant impairment: Contraindicated
Contraindications
- Allergy to class/drug
- <2 months of age (except as PCP prophylaxis)
- Significant hepatic impairment
- Megaloblastic anemia or folate deficiency
- G6PD deficiency
- Pregnancy (class D)
Adverse Reactions
Serious
- Stevens-Johnson Syndrome
- Toxic Epidermal Necrolysis
- Fulminant hepatic necrosis
- Agranulocytosis
- Aplastic anemia
- Blood dyscrasias
- Thrombocytopenia
- Hypersensitivity Reaction
- Photosensitivity
- Hepatotoxicity
- Pancreatitis
- Intersitial nephritis
- Renal Failure
- Pulmonary infiltrates
- Myelosuppression
- Methemoglobinemia
- Hyperkalemia
- Hyponatremia
- Aseptic meningitis
- Seizures
- Lupus Erythematosus
- Hypoglycemia
- Clostridium difficile
- Rhabdomyolysis
- Congenital malformations
- Congenital neural tube defects
- Kernicterus (neonates)
Common
- Nausea and Vomiting
- Anorexia
- Rash
- Urticaria
- Hypersensitivity Reaction
- Photosensitivity
- Diarrhea
- Dizziness
- Dyspepsia
- Headache
- Lethargy
Pharmacology
- Half-life: 6-12h (20-50h ESRD)
- Metabolism:
- Hepatic
- Excretion:
- Urine - both as unchanged drug and metabolites
- Mechanism of Action: Bactericidal via interfering with folic acid synthesis
Antibiotic Sensitivities[2]
Key
- S susceptible/sensitive (usually)
- I intermediate (variably susceptible/resistant)
- R resistant (or not effective clinically)
- S+ synergistic with cell wall antibiotics
- U sensitive for UTI only (non systemic infection)
- X1 no data
- X2 active in vitro, but not used clinically
- X3 active in vitro, but not clinically effective for Group A strep pharyngitis or infections due to E. faecalis
- X4 active in vitro, but not clinically effective for strep pneumonia
Comments
Bactrim dosing is based on the trimethoprim part not the sulfamethoxazole part.
- The dosing in 8-10mg/kg of trimethoprim divided q12 hours (4-5 mg/kg per dose).
- The concentration of Bactrim is 200 mg of sulfamethoxazole and 40 mg of trimethoprim in 5 mL.
- Example: 10 kg child - 8mg/kg per day of trimethoprim part which is 80 mg per day. Divide by 2 = 40 mg of trimethoprim per dose. Based on the above concentration patient will get 5 mL of Bactrim 2 times per day.
See Also
References
- ↑ Trimethoprim-sulfamethoxazole (co-trimoxazole): Drug information. UpToDate. www.uptodate.com. Accessed April 2, 2019.
- ↑ Sanford Guide to Antimicrobial Therapy 2014
- ↑ GlobalRPH. Bactrim. Last revised 10/2009. http://www.globalrph.com/bactrim_dilution.htm.
- ↑ GlobalRPH. Bactrim. Last revised 10/2009. http://www.globalrph.com/bactrim_dilution.htm.