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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 / 3
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✔✔ 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 / 3
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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?
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