Study objective: To compare the extent of oral
clarithromycin absorption in patients during an illness and in
Design: Sequential two-phase prospective study
including an acutely ill pneumonia phase (PP) and a subsequent
convalescent phase (CP).
Study population: Patients≥
18 years old with radiographically confirmed community-acquired
pneumonia (CAP) who were admitted to the hospital.
Methods: During both study phases, patients received one
single 500-mg dose of oral clarithromycin. Serial blood samples were
drawn over a 24-h period in order to characterize the plasma
concentration-time curves. Area under the curve from zero to 24 h
(AUC0–24), maximum plasma concentration
(Cmax), and time to maximum concentration (Tmax) were determined for
both clarithromycin and its metabolite, 14-hydroxyclarithromycin, and
compared between the two phases.
patients completed both phases of the study. For clarithromycin, there
was a significant increase AUC0–24 (47.37 ± 8.51μ
g/h/mL vs 36.22 ± 6.09 μg/h/mL) in favor of the PP. There were
no significant differences detected with respect to Cmax
(4.32 ± 0.63 μg/mL vs 3.57 ± 0.46 μg/mL), or Tmax
(3.50 ± 0.50 h vs 2.83 ± 0.59 h) between PP and CP. For
14-hydroxyclarithromycin, the AUC0–24 and Cmax were
significantly higher (5.84 ± 1.08 μg/h/mL vs 8.84 ± 1.92μ
g/h/mL; 0.42 ± 0.08 μg/mL vs 0.76 ± 0.23 μg/mL) in the CP
as compared to the PP. Tmax remained unchanged.
Conclusion: The extent of absorption of oral clarithromycin
was not diminished during an acute illness with CAP.