Penetration of clarithromycin into middle ear fluid of children with acute otitis media.
OBJECTIVE
To determine the steady state plasma and middle ear fluid concentrations of clarithromycin and its metabolite, 14(R)-hydroxyclarithromycin in 32 pediatric patients with acute otitis media.


METHODS
After the sixth dose of a 7.5-mg/kg every-12-h regimen of clarithromycin suspension, tympanocentesis was performed at 2, 4, 8 or 12 hours postdose. Plasma and middle ear fluid samples were assayed for concentrations of clarithromycin and its 14-hydroxy metabolite.


RESULTS
Mean middle ear fluid concentrations ranged from 3.0 to 8.3 micrograms/g during the dosing interval for clarithromycin and from 1.5 to 3.8 micrograms/g for 14(R)-hydroxyclarithromycin. The mean middle ear fluid concentrations were consistently greater than corresponding mean plasma concentrations, which ranged from 0.7 to 3.4 micrograms/ml for clarithromycin and from 0.8 to 1.8 micrograms/ml for 14(R)-hydroxyclarithromycin. The ratios of middle ear fluid to plasma concentration appeared to increase during the dosing interval and were 8.8 and 3.8 for clarithromycin and 14(R)-hydroxyclarithromycin, respectively, 12 h after dosing.


CONCLUSIONS
Multiple oral doses of clarithromycin suspension produced sustained middle ear fluid concentrations of clarithromycin and 14(R)-hydroxyclarithromycin which exceed the minimum inhibitory concentrations of most otic pathogens.
Gan
V N
VN
Children's Medical Center of Dallas, TX 75235, USA. vangan@childmed.dallas.tx.us
McCarty
J M
JM
Chu
S Y
SY
Carr
R
R
D000208:Acute Disease; D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000493:pharmacokinetics* / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D017291:Clarithromycin / Q000031:analogs & derivatives / Q000032:analysis / Q000378:metabolism / Q000493:pharmacokinetics* / Q000627:therapeutic use; D004432:Ear, Middle / Q000378:metabolism; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010034:Otitis Media with Effusion / Q000188:drug therapy* / Q000378:metabolism
D000900:Anti-Bacterial Agents; C056228:14-hydroxyclarithromycin; D017291:Clarithromycin