Question 1

This first-pass effect is of particular concern when drugs are administered:

Accepted Answer

The first-pass effect refers to the metabolic processes that occur in the liver and intestines after an oral drug is absorbed. Therefore, drugs administered orally (choice E) are of particular concern as they must undergo the first-pass effect before reaching systemic circulation. Other routes of administration such as topical, intravenous, subcutaneous, or inhalation (choices A, B, C, and D) do not involve the same degree of first-pass metabolism.

Question 2

A drug that has a volume of distribution of approximately 42 L will typically be:

Accepted Answer

A volume of distribution of approximately 42 L suggests that the drug is distributed uniformly throughout all of the body fluids, as this volume approximates the total body water in an average adult.

Question 3

Iontophoresis,phonophoresis,and medicated patches all use the _____ route to administer drugs.

Accepted Answer

Iontophoresis and phonophoresis both use electric current and sound waves, respectively, to enhance the penetration of drugs through the skin. Medicated patches, on the other hand, contain drugs that diffuse through the skin and enter the bloodstream. Therefore, all three methods use the transdermal route to administer drugs.

Question 4

All of the following are parenteral routes of drug administration EXCEPT the ____ route.

Accepted Answer

Parenteral routes of drug administration refer to any route of administration that involves injecting a drug directly into the body, bypassing the digestive system. Inhalation, injection, topical, and transdermal routes are all parenteral routes. Oral administration involves the drug being taken by mouth and passing through the digestive system, making it a non-parenteral route. Therefore, the correct answer is A) oral.

Question 5

Osmosis refers to the special case of diffusion where the diffusing substance is:

Accepted Answer

Osmosis is a specific type of diffusion in which water molecules move from an area of low solute concentration to an area of high solute concentration across a semi-permeable membrane. Therefore, the diffusing substance in osmosis is water.

Question 6

The primary site for drug storage in the body is:

Accepted Answer

Adipose tissue, or fat cells, is where the body primarily stores drugs and other substances. This is due to its high capacity for storage and low blood supply, which helps prevent the drug from being rapidly eliminated from the body.

Question 7

Carrier specificity,expenditure of energy,and ability to transport substances against a concentration gradient are all characteristics of:

Accepted Answer

Carrier specificity refers to the ability of transport proteins in the cell membrane to selectively transport certain substances. This is a characteristic of active transport, which requires energy to move substances against their concentration gradient. Facilitated diffusion, on the other hand, does not require energy and relies on transport proteins to move substances down their concentration gradient. Endocytosis and exocytosis involve the engulfment or secretion of large molecules or particles and are not necessarily related to carrier specificity or energy expenditure.

Question 8

The ______ effect occurs when drugs are initially transported to the liver where a significant amount of the drug may be metabolized and destroyed before the drug reaches its primary site of action.

Accepted Answer

The first-pass effect, also known as presystemic metabolism, occurs when a significant amount of a drug is metabolized by the liver before it reaches its target site of action. This can result in a lower bioavailability of the drug, meaning that less of the drug is available to produce its desired effects.

Question 9

When crossing cell membranes,drugs will diffuse more readily through the lipid layer if they are:

Accepted Answer

Lipid layers are hydrophobic, meaning they repel molecules with charge. Therefore, drugs that are in a neutral, nonionized form will diffuse more readily through the lipid layer. Conversely, charged molecules such as those in (C) will have more difficulty crossing the membrane. Non-lipid soluble molecules as described in (A) will also have difficulty crossing the membrane. Large proteins as described in (D) are too big to passively diffuse across the membrane and require specific transport mechanisms.

Question 10

The extent to which a drug reaches the systemic circulation is referred to as:

Accepted Answer

Bioavailability refers to the extent and rate at which a drug reaches the systemic circulation after administration. It takes into account the portion of the drug that enters the bloodstream and is available to produce pharmacological effects.

Quiz 2: Pharmacokinetics Idrug Administration, absorption, and Distribution