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Re-examining Naloxone Pharmacokinetics After Intranasal and Intramuscular Administration Using the Finite Absorption
Athanasios A Tsekouras1,2, Panos Macheras3,4
1Department of Chemistry, Laboratory of Physical Chemistry, National and Kapodistrian University of Athens, Athens, Greece.
Naloxone pharmacokinetics differ by administration route. Zero-order absorption models better describe intramuscular and intranasal naloxone delivery over finite times compared to traditional models.
Area of Science:
- Pharmacology
- Drug Delivery Systems
- Pharmacokinetics
Background:
- Naloxone is crucial for opioid overdose reversal.
- Administration routes include intravenous, intramuscular, and intranasal.
- Existing data suggest route-dependent pharmacokinetic differences.
Purpose of the Study:
- To analyze naloxone pharmacokinetic data using a finite absorption time model.
- To compare absorption kinetics across different naloxone administration routes.
Main Methods:
- Utilized pre-derived model equations.
- Performed least squares analysis on 24 blood concentration-time datasets for naloxone.
- Applied the finite absorption time concept.
Main Results:
- Intramuscular and intranasal naloxone absorption are more accurately modeled by zero-order kinetics over finite times.
- This contrasts with classical first-order kinetics assuming infinite absorption time.
- Model parameters directly yield absorption duration for comparison.
Conclusions:
- One-compartment models are generally sufficient; two-compartment models offer more detail but with higher uncertainty.
- Absorption duration can be directly calculated, facilitating route comparison.
- Intramuscular injection site impacts drug absorption duration.
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