title: Disposition of intramuscular cefonicid in elderly patients.
abstract: OBJECTIVE
  To examine the disposition of intramuscular (IM) cefonicid in elderly patients with bacterial pneumonia.
  
  
  METHODS
  Pharmacokinetic study.
  
  
  METHODS
  A 620-bed university-affiliated long-term care institution with its own 39-bed acute care unit.
  
  
  METHODS
  Nine consecutive elderly patients with bacterial pneumonia treated with IM cefonicid.
  
  
  METHODS
  Blood samples were collected on the seventh day of therapy over a 24-hour period and analyzed by high performance liquid chromatography. Pharmacokinetics parameters (volume of distribution, half-life, and clearance) and protein binding were calculated. Clinical outcome of IM cefonicid therapy was also noted.
  
  
  RESULTS
  The estimated creatinine clearance (CIcr) ranged from 32 to 145 mL/min. Peak cefonicid serum concentrations occurred at 0.5-1.5 hours, with a mean value of 118 +/- 41 micrograms/mL. Cefonicid concentrations declined monoexponentially to 57 +/- 16 micrograms/mL at 12 hours and 28 +/- 14 micrograms/mL at 24 hours. The mean apparent distribution volume was 0.2 +/- 0.07 L/kg, and the mean apparent total clearance was 15 +/- 12 mL/min. The half-life ranged from 3.1 to 38 hours. A linear correlation was noted between Clcr and cefonicid clearance (r = 0.99).
  
  
  CONCLUSIONS
  Cefonicid absorption was variable among these patients, and the serum half-life was longer than previous values noted in younger patients with similar degree of renal dysfunction. Pharmacokinetic and clinical outcome data from our study group indicate the potential role of IM cefonicid in treating elderly patients with bacterial pneumonia.
authors.affiliation: Department of Pharmacy, Monroe Community Hospital, Rochester, New York 14620.
authors.forename: S D
authors.initials: SD
authors.lastname: Karki
authors.forename: D W
authors.initials: DW
authors.lastname: Bentley
authors.forename: A
authors.initials: A
authors.lastname: Luzier
authors.forename: C
authors.initials: C
authors.lastname: Taylor
authors.forename: G D
authors.initials: GD
authors.lastname: Morse
mesh_terms: D000042:Absorption; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001424:Bacterial Infections / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism; D015790:Cefonicid / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid; D003404:Creatinine / Q000097:blood / Q000493:pharmacokinetics; D004341:Drug Evaluation; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D011014:Pneumonia / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism; D011485:Protein Binding; D014018:Tissue Distribution; D016896:Treatment Outcome
chemical_list: D015790:Cefonicid; D003404:Creatinine