Doxycycline and tetracycline exhibit differences in their pharmacokinetic profiles. Doxycycline boasts superior bioavailability, reaching peak serum concentrations more rapidly after oral administration than tetracycline. This improved absorption leads to higher and more sustained blood levels.
Distribution varies slightly. Doxycycline achieves higher concentrations in tissues like lungs and prostate, making it more effective for treating certain infections. Both drugs, however, concentrate within bone and teeth, a consideration for pediatric patients.
Elimination differs significantly. Tetracycline primarily undergoes renal excretion, making dose adjustment necessary for individuals with kidney impairment. Conversely, doxycycline is eliminated through both renal and fecal routes, offering a more flexible dosing strategy in patients with reduced kidney function, although modifications may still be needed in cases of severe impairment.
These pharmacokinetic differences directly impact therapeutic efficacy and safety, necessitating careful consideration when selecting an appropriate antibiotic.
