Fundamental Notions Part 1 Flashcards
What is pharmacodynamics?
Pharmacodynamics describes how drugs work and affect the body, specifically their mechanisms of action leading to physiological effects.
What distinguishes medicinal drugs from nonmedicinal (social) drugs?
Medicinal drugs are used for the prevention, treatment, and diagnosis of diseases, whereas nonmedicinal drugs are used for recreational purposes, including both illegal substances and everyday items like caffeine and alcohol.
What does the term “affinity” mean in the context of drug-target interactions?
Affinity refers to the ability of a drug to bind to its target and the strength of the interaction between the drug and its target.
How is the Equilibrium Dissociation Constant (Kd) related to drug affinity?
The Kd is the concentration of a drug at which 50% of its target is occupied; a lower Kd indicates a higher affinity, meaning the drug binds more effectively to its target.
What does the Therapeutic Index (TI) indicate?
The Therapeutic Index (TI) is a measure of a drug’s relative safety, calculated as the ratio of the dose that causes toxicity (TD50) to the dose that produces a therapeutic effect (ED50). A higher TI suggests a safer drug.
What is the mechanism of action of ibuprofen?
Ibuprofen works by binding to cyclooxygenase (COX) enzymes, inhibiting their function and thereby reducing the production of prostaglandins, which are involved in pain, inflammation, and fever.
What are the four main classes of drug targets?
The four main classes of drug targets are receptors, ion channels, transporters/carriers, and enzymes.
What role do ion channels play in cellular signalling?
Ion channels allow the regulated passage of ions across the cell membrane, converting chemical signals into electrical signals, which is crucial for processes like muscle contraction and neurotransmission.
How does a competitive antagonist differ from a non-competitive antagonist?
A competitive antagonist binds to the same site as the agonist, blocking its action, while a non-competitive antagonist binds to a different site and inhibits the receptor’s function regardless of the agonist’s presence.
What does the term “Emax” refer to in pharmacology?
Emax refers to the maximal effect that a drug can produce, indicating its efficacy. A higher Emax signifies a drug’s greater potential to produce a desired biological response.
What is the significance of the Equilibrium Dissociation Constant (Kd)?
Kd is the concentration of a ligand or drug at which 50% of its target is occupied. A lower Kd indicates a higher affinity of the drug for its target.
How does a drug’s potency relate to its EC50 value?
Potency refers to the amount of drug needed to achieve a desired effect. A lower EC50 value means that a smaller concentration of the drug is required to elicit 50% of the maximal response, indicating higher potency.
What is the Therapeutic Index (TI), and why is it important?
The Therapeutic Index is a measure of a drug’s relative safety, calculated as TD50 (toxic dose for 50% of the population) divided by ED50 (effective dose for 50% of the population). A higher TI indicates a wider margin of safety.
What is the difference between therapeutic effects and side effects?
Therapeutic effects are the desired beneficial outcomes of a drug, while side effects are unintended and often undesirable effects that occur alongside the therapeutic effects.
Describe how allosteric modulators influence receptor activity.
Allosteric modulators bind to a different site on the receptor than the endogenous agonist, either enhancing (positive allosteric modulators) or reducing (negative allosteric modulators) the effect of the agonist on the receptor.
