[Laboratory studies on doxycycline intravenous (author's transl)]

Area of Science:

• Pharmacology
• Microbiology

Context:

• Doxycycline is a broad-spectrum antibiotic.
• Understanding its pharmacokinetic properties is crucial for effective therapeutic use.
• Laboratory and clinical studies are essential to determine optimal administration routes and dosages.

Purpose:

• To evaluate the stability and efficacy of intravenous doxycycline.
• To compare the pharmacokinetic profiles of intravenous versus oral doxycycline administration.
• To assess doxycycline accumulation and excretion patterns.

Summary:

• Doxycycline exhibited the largest zones of growth inhibition in phosphate buffer (pH 7.2), with varying efficacy in different biological systems (lung, liver, kidney).
• Intravenous doxycycline (200 mg) resulted in higher initial blood concentrations compared to oral administration, with similar levels after 3 hours.
• No accumulation was observed after three days of intravenous doxycycline administration (100-200 mg daily).
• In a patient with chronic broncho-bronchitis, sputum doxycycline levels reached 30-40% of serum levels.
• Urinary excretion was higher after a single intravenous dose (47.0%) compared to oral administration (26.5%).

Impact:

• Provides data supporting the efficacy of intravenous doxycycline administration.
• Informs optimal dosing strategies and route selection for doxycycline therapy.
• Contributes to understanding doxycycline's distribution and elimination in the body.