Dosage Interval and Administration Route: Determination Methods

Dosage regimen calculations for multiple intravenous administrations involve determining both the appropriate drug dose and optimal dosing intervals. These calculations are based on the ratio of maximum to minimum drug concentrations, where k is the elimination rate constant and τ, the dosing interval.

To establish an antibiotic dosage interval, one should consider its half-life, target concentration range in the bloodstream, and the patient's volume of distribution.

For example, an antibiotic with a three-hour half-life aiming for a concentration range of 5 to 15 µg/mL would have a dosing interval of 4.76 hours to maintain therapeutic levels.

Choosing an appropriate route of drug administration involves assessing the drug's gastrointestinal stability, susceptibility to first-pass metabolism, and the required onset of action.

Intravenous routes are ideal for drugs needing rapid action or those unstable in the GI tract. In contrast, oral or intramuscular routes suit drugs requiring slower absorption or sustained-release.