Pharmacology Made Easy 5.0
Introduction to Pharmacology Test
Questions and Answers | Latest Version
| 2025/2026 | Correct & Verified
How does pharmacokinetics differ from pharmacodynamics?
✔✔ Pharmacokinetics studies how the body processes drugs (absorption, distribution,
metabolism, excretion), while pharmacodynamics examines how drugs affect the body
(mechanisms of action and effects).
Why is the first-pass effect important in drug administration?
✔✔ The first-pass effect reduces drug bioavailability because the liver metabolizes drugs before
they reach systemic circulation, requiring dosage adjustments for some medications.
What role do cytochrome P450 enzymes play in drug metabolism?
✔✔ Cytochrome P450 enzymes in the liver break down drugs, influencing their duration of
action and potential interactions with other medications.
How does a competitive antagonist differ from a non-competitive antagonist?
1
,✔✔ A competitive antagonist binds reversibly to the same receptor as an agonist, blocking its
effects, while a non-competitive antagonist binds irreversibly or at a different site, reducing the
receptor's maximum response.
What factors influence drug absorption in the body?
✔✔ Drug absorption depends on route of administration, solubility, blood flow, surface area, and
molecular size.
Why is the therapeutic index significant in prescribing medications?
✔✔ The therapeutic index compares a drug's effective dose to its toxic dose, helping determine
its safety margin.
What is the difference between a side effect and an adverse drug reaction?
✔✔ A side effect is a predictable, often mild reaction to a drug, while an adverse drug reaction is
harmful, unintended, and sometimes severe.
How does tolerance develop to a medication over time?
✔✔ Tolerance occurs due to repeated drug exposure, leading to reduced effectiveness from
receptor desensitization, increased metabolism, or compensatory bodily responses.
2
, What is the significance of the blood-brain barrier in pharmacology?
✔✔ The blood-brain barrier selectively restricts drug passage into the brain, protecting it from
toxins but complicating treatment for CNS disorders.
Why must some drugs be administered parenterally instead of orally?
✔✔ Parenteral administration bypasses digestion and first-pass metabolism, ensuring full
bioavailability for drugs destroyed by stomach acid or liver enzymes.
How do prodrugs differ from active drugs?
✔✔ Prodrugs are inactive when administered and require metabolic conversion in the body to
become therapeutically active.
What is the role of plasma protein binding in drug distribution?
✔✔ Drugs bound to plasma proteins remain inactive in circulation, while free (unbound) drugs
exert pharmacological effects.
Why are loading doses used in some drug therapies?
3
Introduction to Pharmacology Test
Questions and Answers | Latest Version
| 2025/2026 | Correct & Verified
How does pharmacokinetics differ from pharmacodynamics?
✔✔ Pharmacokinetics studies how the body processes drugs (absorption, distribution,
metabolism, excretion), while pharmacodynamics examines how drugs affect the body
(mechanisms of action and effects).
Why is the first-pass effect important in drug administration?
✔✔ The first-pass effect reduces drug bioavailability because the liver metabolizes drugs before
they reach systemic circulation, requiring dosage adjustments for some medications.
What role do cytochrome P450 enzymes play in drug metabolism?
✔✔ Cytochrome P450 enzymes in the liver break down drugs, influencing their duration of
action and potential interactions with other medications.
How does a competitive antagonist differ from a non-competitive antagonist?
1
,✔✔ A competitive antagonist binds reversibly to the same receptor as an agonist, blocking its
effects, while a non-competitive antagonist binds irreversibly or at a different site, reducing the
receptor's maximum response.
What factors influence drug absorption in the body?
✔✔ Drug absorption depends on route of administration, solubility, blood flow, surface area, and
molecular size.
Why is the therapeutic index significant in prescribing medications?
✔✔ The therapeutic index compares a drug's effective dose to its toxic dose, helping determine
its safety margin.
What is the difference between a side effect and an adverse drug reaction?
✔✔ A side effect is a predictable, often mild reaction to a drug, while an adverse drug reaction is
harmful, unintended, and sometimes severe.
How does tolerance develop to a medication over time?
✔✔ Tolerance occurs due to repeated drug exposure, leading to reduced effectiveness from
receptor desensitization, increased metabolism, or compensatory bodily responses.
2
, What is the significance of the blood-brain barrier in pharmacology?
✔✔ The blood-brain barrier selectively restricts drug passage into the brain, protecting it from
toxins but complicating treatment for CNS disorders.
Why must some drugs be administered parenterally instead of orally?
✔✔ Parenteral administration bypasses digestion and first-pass metabolism, ensuring full
bioavailability for drugs destroyed by stomach acid or liver enzymes.
How do prodrugs differ from active drugs?
✔✔ Prodrugs are inactive when administered and require metabolic conversion in the body to
become therapeutically active.
What is the role of plasma protein binding in drug distribution?
✔✔ Drugs bound to plasma proteins remain inactive in circulation, while free (unbound) drugs
exert pharmacological effects.
Why are loading doses used in some drug therapies?
3
