Pharmacokinetics of oral vs. intravenous dexamethasone in patients hospitalized with community-acquired pneumonia

Aim The use of corticosteroids as adjunctive therapy might be effective in patients with community-acquired pneumonia (CAP). Oral administration of dexamethasone is a practical and safer alternative to the intravenous route. Since patients hospitalized with pneumonia might have delayed gastric emptying, this study explored systemic exposure in terms of area under the concentration-time curve (AUC) of oral dexamethasone in patients hospitalized with CAP. Methods In this randomized, open label study, 30 patients admitted with CAP were randomized to receive either 4mg intravenous or 6mg oral dexamethasone for 4consecutive days. Serial blood samples were obtained before and after drug administration. Results Median AUC to infinity was 626gl-1h (IQR 401-1161) for the intravenous group and 774gl-1h (IQR 618-1146) for the oral group. The AUC ratio of 6mg oral and 4mg intravenous dexamethasone was 1.22 (95% confidence interval (CI) 0.81, 1.82), which represents a bioavailability of 81% (95% CI 54, 121) after correction for differences in dexamethasone dose. Conclusions Bioavailability of oral dexamethasone in patients hospitalized with pneumonia is sufficient. This makes oral dexamethasone an appropriate alternative for intravenous administration in these patients.