Session 7_Change From Route to Route Flashcards
What is a Route of Administration?
The path by which a drug is introduced into the body (e.g., oral, intravenous, intramuscular, topical).
Why is the route of administration important?
It significantly influences drug absorption, distribution, and ultimately, therapeutic effect.
What is the need for dose adjustment when changing the route of administration?
Changing the route often necessitates adjusting the dose to maintain therapeutic equivalence.
Define Bioavailability.
The fraction of the administered drug that reaches the systemic circulation unchanged.
What is First-Pass Metabolism?
Drugs administered orally may undergo significant first-pass metabolism in the liver before reaching systemic circulation.
What drug properties affect absorption and distribution across different routes?
Physicochemical properties of the drug (e.g., solubility, molecular weight).
What patient factors can impact drug disposition?
Age, weight, renal and hepatic function.
What is the typical dose adjustment when switching from Oral to Intravenous?
Often requires a significant dose reduction due to higher bioavailability of intravenous route.
What is the typical dose adjustment when switching from Intravenous to Oral?
May require a dose increase to achieve the same therapeutic effect due to lower bioavailability of the oral route.
What type of dose adjustments may be necessary when switching from Oral to Intramuscular?
Dose adjustments may be necessary depending on the drug’s bioavailability and absorption characteristics.
What is the typical requirement when switching from Topical to Oral/Parenteral?
Typically requires significant dose adjustments due to limited systemic absorption from topical application.
What is Therapeutic Drug Monitoring?
May be necessary to monitor drug levels and adjust doses accordingly, especially when switching between routes.
Why is patient monitoring important after a route change?
To closely monitor patients for therapeutic efficacy and adverse effects.
What should be considered when making dose adjustments?
Individual patient factors.
What are the ideal characteristics for conversion to oral dosage forms?
Oral dosage form should have:
* Excellent bioavailability (ideally greater than 80%)
* Be well tolerated upon administration
* Supported by clinical data
* Availability of multiple oral dosage forms
* Dosing frequency equivalent to or less than the IV formulation.
List the three types of IV to PO therapy conversions.
- Sequential therapy
- Switch therapy
- Step down therapy
What is Sequential therapy?
Refers to the act of replacing a parenteral version of a medication with its oral counterpart.
Give an example of Sequential therapy.
The conversion of famotidine 20 mg IV to famotidine 20 mg PO.
What is Switch therapy?
Describes a conversion from an IV medication to the PO equivalent that may be within the same class and have the level of potency, but is a different compound.
Give an example of Switch therapy.
The conversion of IV pantoprazole to rapidly dissolving lansoprazole tablets or omeprazole capsules.
What is Step-down therapy?
Refers to converting from an injectable medication to an oral agent in another class or to a different medication within the same class.
Give an example of Step-down therapy.
Converting from ampicillin/sulbactam 3 g IV to amoxicillin/clavulanate 875 mg PO.
What methods can be used to calculate an appropriate oral dosage regimen for a patient stabilized by an IV drug infusion?
Both methods assume that the patient’s plasma drug concentration is at steady state.
What is a key conclusion regarding changing routes of administration?
Changing the route can significantly impact its therapeutic effect.
What factors are crucial for appropriate dose adjustments?
Bioavailability, first-pass metabolism, and patient characteristics.
What is essential after a route change?
Close monitoring of patients to ensure safety and efficacy.
