NU150 | NU150 Pharmacology Midterm v2 |
Questions with Correct Answers and Expert
Explanation for Each Question | Galen
1. Which phase of pharmacokinetics is primarily affected when a drug is administered
via the intravenous route?
A. Metabolism
B. Distribution
C. Absorption
D. Excretion
Correct Answer: C
Expert Explanation: The intravenous route bypasses the absorption process
entirely because the medication is delivered directly into the systemic circulation.
This results in a 100% bioavailability of the drug, meaning there is no delay in
therapeutic onset. Other routes, such as oral or subcutaneous, require the drug to
cross membranes to enter the bloodstream.
2. A patient with liver failure is prescribed a drug that is extensively metabolized by
the liver. What should the nurse monitor for?
A. Signs of drug toxicity
B. Reduced therapeutic effect
,C. Rapid excretion of the drug
D. Enhanced drug absorption
Correct Answer: A
Expert Explanation: Liver failure reduces the organ’s ability to metabolize and
break down drugs into inactive metabolites. This leads to the drug remaining in the
system for a longer duration, increasing the plasma concentration to potentially
toxic levels. The nurse must monitor for adverse reactions and expect a possible
dose reduction from the provider.
3. A drug has a half-life of 4 hours. If 100 mg is administered, how much of the drug
remains in the body after 12 hours?
A. 12.5 mg
B. 25 mg
C. 50 mg
D. 6.25 mg
Correct Answer: A
Expert Explanation: The half-life is the time required for the concentration of a
drug to decrease by half. After one half-life (4 hours), 50 mg remains; after two (8
,hours), 25 mg remains; and after three (12 hours), 12.5 mg remains. Understanding
half-life is critical for determining dosing intervals and predicting drug clearance.
4. Which of the following terms describes the maximal efficacy of a drug?
A. Ceiling Effect
B. Affinity
C. Therapeutic Index
D. Potency
Correct Answer: A
Expert Explanation: The ceiling effect occurs when the therapeutic response of a
drug no longer increases despite further increases in the dose. It represents the
point of maximal efficacy beyond which the patient only risks increased toxicity
without additional benefit. This is a common concept in analgesics like NSAIDs.
5. A nurse is teaching a patient about a newly prescribed medication with a narrow
therapeutic index. Which statement is correct?
A. There is a small margin between the effective and lethal dose.
B. The drug is very safe and requires no monitoring.
C. The drug will take a long time to reach steady state.
D. The patient should take double the dose if they miss one.
, Correct Answer: A
Expert Explanation: A narrow therapeutic index means that the difference
between the dose that produces a therapeutic effect and the dose that produces
toxic effects is very small. Medications in this category, such as digoxin or lithium,
require close blood level monitoring to ensure patient safety. Patients must be
educated on the importance of strict adherence and regular lab tests.
6. What is the primary purpose of the ‘First-Pass Effect’ in pharmacology?
A. To increase the bioavailability of oral drugs.
B. To facilitate rapid excretion through the kidneys.
C. The metabolism of a drug by the liver before it reaches systemic circulation.
D. To enhance the distribution of drugs to the brain.
Correct Answer: C
Expert Explanation: The first-pass effect occurs when an orally administered drug
is absorbed from the GI tract and carried to the liver via the portal vein. In the liver,
a significant portion of the drug may be metabolized and inactivated before it ever
reaches the rest of the body. This is why some drugs must be given via non-oral
routes to be effective.
7. An agonist is a medication that performs which of the following actions?
A. Blocks a receptor to prevent a response.
Questions with Correct Answers and Expert
Explanation for Each Question | Galen
1. Which phase of pharmacokinetics is primarily affected when a drug is administered
via the intravenous route?
A. Metabolism
B. Distribution
C. Absorption
D. Excretion
Correct Answer: C
Expert Explanation: The intravenous route bypasses the absorption process
entirely because the medication is delivered directly into the systemic circulation.
This results in a 100% bioavailability of the drug, meaning there is no delay in
therapeutic onset. Other routes, such as oral or subcutaneous, require the drug to
cross membranes to enter the bloodstream.
2. A patient with liver failure is prescribed a drug that is extensively metabolized by
the liver. What should the nurse monitor for?
A. Signs of drug toxicity
B. Reduced therapeutic effect
,C. Rapid excretion of the drug
D. Enhanced drug absorption
Correct Answer: A
Expert Explanation: Liver failure reduces the organ’s ability to metabolize and
break down drugs into inactive metabolites. This leads to the drug remaining in the
system for a longer duration, increasing the plasma concentration to potentially
toxic levels. The nurse must monitor for adverse reactions and expect a possible
dose reduction from the provider.
3. A drug has a half-life of 4 hours. If 100 mg is administered, how much of the drug
remains in the body after 12 hours?
A. 12.5 mg
B. 25 mg
C. 50 mg
D. 6.25 mg
Correct Answer: A
Expert Explanation: The half-life is the time required for the concentration of a
drug to decrease by half. After one half-life (4 hours), 50 mg remains; after two (8
,hours), 25 mg remains; and after three (12 hours), 12.5 mg remains. Understanding
half-life is critical for determining dosing intervals and predicting drug clearance.
4. Which of the following terms describes the maximal efficacy of a drug?
A. Ceiling Effect
B. Affinity
C. Therapeutic Index
D. Potency
Correct Answer: A
Expert Explanation: The ceiling effect occurs when the therapeutic response of a
drug no longer increases despite further increases in the dose. It represents the
point of maximal efficacy beyond which the patient only risks increased toxicity
without additional benefit. This is a common concept in analgesics like NSAIDs.
5. A nurse is teaching a patient about a newly prescribed medication with a narrow
therapeutic index. Which statement is correct?
A. There is a small margin between the effective and lethal dose.
B. The drug is very safe and requires no monitoring.
C. The drug will take a long time to reach steady state.
D. The patient should take double the dose if they miss one.
, Correct Answer: A
Expert Explanation: A narrow therapeutic index means that the difference
between the dose that produces a therapeutic effect and the dose that produces
toxic effects is very small. Medications in this category, such as digoxin or lithium,
require close blood level monitoring to ensure patient safety. Patients must be
educated on the importance of strict adherence and regular lab tests.
6. What is the primary purpose of the ‘First-Pass Effect’ in pharmacology?
A. To increase the bioavailability of oral drugs.
B. To facilitate rapid excretion through the kidneys.
C. The metabolism of a drug by the liver before it reaches systemic circulation.
D. To enhance the distribution of drugs to the brain.
Correct Answer: C
Expert Explanation: The first-pass effect occurs when an orally administered drug
is absorbed from the GI tract and carried to the liver via the portal vein. In the liver,
a significant portion of the drug may be metabolized and inactivated before it ever
reaches the rest of the body. This is why some drugs must be given via non-oral
routes to be effective.
7. An agonist is a medication that performs which of the following actions?
A. Blocks a receptor to prevent a response.
