Routes of Drug Administration Multiple Choice Questions Quiz

What is one of the fundamental considerations in dosage form design?

How are local effects achieved?

Which dosage form provides the longest duration of action for nitroglycerin?

What is a characteristic of the sublingual, intravenous, and buccal forms of nitroglycerin?

Why do some dosage forms of nitroglycerin require multiple dosing?

What distinguishes systemic effects from local effects?

What is the fraction of drug that enters systemic circulation and is ultimately available to exert its effect for drugs undergoing a significant first-pass effect?

Which route of administration can be considered to avoid the first-pass effect for drugs with significant first-pass metabolism?

If metabolites of a drug are pharmacologically active, how does this impact the oral dosage required for the desired therapeutic effect?

Under what conditions can the flow of blood through the liver be decreased?

For drugs with inactive metabolites, why is a larger oral dose required to achieve the desired therapeutic effect compared to routes with no first-pass effect?

Which drug is mentioned as an example that exhibits the effect of requiring a larger oral dose due to inactive metabolites?

Dosage Form Design and Routes of Administration

Drugs can be administered using various dosage forms and routes of administration.
The choice of dosage form and route of administration depends on whether the drug is intended for local or systemic effects.

Local vs Systemic Effects

Local effects are achieved by direct application of the drug to the desired site of action (e.g., eye, nose, or skin).
Systemic effects result from the entrance of the drug into the circulatory system and transport to the cellular site of its action.

Drug Absorption and Onset of Action

Different dosage forms can result in different drug absorption rates and times of onset, peak, and duration of action.
For example, sublingual, intravenous, and buccal forms of nitroglycerin have extremely rapid onsets of action, while oral and topical forms have slower onsets of action but greater durations of action.

First-Pass Effect

The bioavailability of a drug is lowest when it undergoes a significant first-pass effect.
The first-pass effect is calculated as the hepatic extraction ratio, or the fraction of drug metabolized (E).
The fraction of drug that enters the systemic circulation and is ultimately available to exert its effect is equal to (1 − E).
Examples of drugs that undergo a significant first-pass effect when administered orally include propranolol, verapamil, and metoprolol.

Compensating for First-Pass Effect

To compensate for the first-pass effect, manufacturers may consider alternative routes of administration, such as intravenous, intramuscular, or sublingual.
The dosage must be adjusted accordingly to avoid adverse effects.
The metabolites themselves may be pharmacologically active or inactive, affecting the dosage required to achieve the desired therapeutic effect.

Test your knowledge on the various dosage forms and routes of drug administration, including local and systemic effects. Understand the fundamental considerations in dosage form design for drugs intended for specific effects.