title: [Cotrimoxazole in bone-related infections: toxicity and clinical and economic impact].
abstract: BACKGROUND
  Cotrimoxazole is a therapeutic option for bone-related infections but is associated to hyperkalemia and renal failure. Tolerance to this drug may reduce length of stay (LOS) and hospital charges.
  
  
  OBJECTIVE
  To evaluate renal, potassium toxicity, clinical outcome, and use of hospital resources in patients treated with cotrimoxazole for bone-related infections.
  
  
  METHODS
  Retrospective analysis of adult patients with bone-related infections confirmed by culture and treated with this drug. Serum potassium and creatinine levels were analyzed during follow-up and risk factors for hyperkalemia were searched. Length of stay (LOS) and hospital charges were compared. Clinical outcome was evaluated as a secondary endpoint.
  
  
  RESULTS
  From 2011 to 2014, 23 patients were identified (mean age 64.7 years). Diabetes mellitus, peripheral vascular disease, and previous amputations prevalence were high (82.6%, 47.8%, and 43.5%, respectively). Median serum potassium concentration increased significantly at first control (4.35 mEq/L to 4.9 mEq/L; p < 0.001), and also creatinine serum concentration (0.9 to 1.1 mg/dL; p < 0.05). Seven patients developed hyperkalemia. Cotrimoxazole was discontinued in 10 patients (43.5%), and in 6, discharge was postponed. Drugs active against the renin-angiotensin system (DAARAS) were associated with kyperkalemia (OR 10.8 IC95 1.37-85; p < 0.05). LOS was higher among patients with cotrimoxazole toxicity (median LOS 56 versus 30 days, p < 0.05). Patients with no cotrimoxazole interruption had less drug-related hospital charges (median values of 563 versus 2820 USD, respectively; p < 0.01).
  
  
  CONCLUSIONS
  Cotrimoxazole use must be monitored in order to detect hyperkalemia or renal toxicity and suspend its prescription. Patients that use DAARAS have a higher risk of kyperkalemia. LOS and drug-related hospital charges are reduced when patients can tolerate cotrimoxazole.
authors.forename: Alberto
authors.initials: A
authors.lastname: Fíca
authors.forename: César
authors.initials: C
authors.lastname: Lamas
authors.forename: Felipe
authors.initials: F
authors.lastname: Olivares
authors.forename: Diego
authors.initials: D
authors.lastname: Ramírez
authors.forename: Andrés
authors.initials: A
authors.lastname: Soto
authors.forename: Lorena
authors.initials: L
authors.lastname: Porte
authors.forename: Stephane
authors.initials: S
authors.lastname: Braun
authors.forename: Ignacia
authors.initials: I
authors.lastname: Vlllablanca
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000009:adverse effects* / Q000191:economics / Q000627:therapeutic use; D001850:Bone Diseases, Infectious / Q000188:drug therapy*; D003404:Creatinine / Q000097:blood; D005260:Female; D017048:Health Care Costs; D006801:Humans; D006947:Hyperkalemia / Q000139:chemically induced*; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D012189:Retrospective Studies; D012307:Risk Factors; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000009:adverse effects* / Q000191:economics / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D003404:Creatinine; D011188:Potassium