Pharmacology Dose-Response Quiz
36 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What does the C50 represent in pharmacology?

  • The concentration of the drug (correct)
  • The therapeutic index of the drug
  • The efficacy of a drug
  • The maximal effect of a drug

On which axis of a dose-response curve is potency represented?

  • Y-axis
  • It is not represented on the graph
  • X-axis (correct)
  • Z-axis

How are drug potency and receptor affinity related?

  • They have a direct relationship (correct)
  • They are unrelated
  • They have an indirect relationship
  • Potency depends on affinity but not vice versa

What is represented by the plateau part of a dose-response curve?

<p>Efficacy (A)</p> Signup and view all the answers

What indicates a highly potent drug on a dose-response curve?

<p>Steep slope of the curve (A)</p> Signup and view all the answers

What does the slope of a dose response curve represent?

<p>Number of receptors occupied (C)</p> Signup and view all the answers

What is the therapeutic index calculated from?

<p>LD50 over ED50 (B)</p> Signup and view all the answers

Which option best defines efficacy in pharmacological terms?

<p>The ability of a drug to produce a desired effect (D)</p> Signup and view all the answers

What is the primary reason for using an infusion of opioids instead of single or repeated doses?

<p>The duration of action of opioids is often longer than that of antagonists like flumazenil. (D)</p> Signup and view all the answers

What is a characteristic of antagonists in relation to receptors?

<p>They do not activate receptors and lack efficacy. (A)</p> Signup and view all the answers

Which of the following describes inverse agonists?

<p>They decrease the intrinsic activity of receptors. (A)</p> Signup and view all the answers

Which statement correctly describes the effect of continuous blockade by an antagonist?

<p>It results in the downregulation of the target receptor. (A)</p> Signup and view all the answers

What is the effect of inverse agonists on cyclic AMP?

<p>They decrease cyclic AMP levels. (D)</p> Signup and view all the answers

Naloxone displays which type of pharmacological activity?

<p>Both inverse agonist and antagonist effects. (D)</p> Signup and view all the answers

Which of the following best defines allosteric modulators?

<p>They enhance or diminish the effect of an agonist. (A)</p> Signup and view all the answers

Which statement is true concerning competitive antagonism?

<p>It can be overcome by increasing the concentration of agonists. (C)</p> Signup and view all the answers

What is the primary effect of administering ephedrine to a patient taking metoprolol?

<p>Increases catecholamine levels while facing receptor competition (B)</p> Signup and view all the answers

What role does neostigmine play at the neuromuscular junction?

<p>It prevents the breakdown of acetylcholine to increase receptor activation (D)</p> Signup and view all the answers

In the context of beta-blocker interaction, what may happen even if norepinephrine displaces metoprolol?

<p>Metoprolol can reoccupy the receptor after being displaced (A)</p> Signup and view all the answers

What is a key challenge in sedating patients who are on extended release metoprolol?

<p>It complicates the administration of adrenergic agents (B)</p> Signup and view all the answers

What is the primary function of an allosteric modulator?

<p>To bind to a different site on the receptor (D)</p> Signup and view all the answers

What is the mechanism by which Narcan acts on opioid receptors?

<p>It competes with opioids at their receptors (D)</p> Signup and view all the answers

How does midazolam function as an allosteric modulator of the GABA receptor?

<p>It enhances GABA's effect without binding to the GABA site (D)</p> Signup and view all the answers

What characterizes non-competitive antagonists in clinical use?

<p>They permanently occupy receptors and cannot be displaced (D)</p> Signup and view all the answers

What type of allosteric modulator increases the effect of GABA?

<p>Positive allosteric modulator (A)</p> Signup and view all the answers

Why is there often a need for larger doses of catecholamines in patients on beta blockers?

<p>Catecholamines are less effective against fully occupied receptors (C)</p> Signup and view all the answers

What is the result of a synergistic effect in drug interactions?

<p>The combined effect exceeds the sum of individual effects (A)</p> Signup and view all the answers

What commonality exists between neostigmine and Narcan?

<p>Both act by competing for receptor sites (B)</p> Signup and view all the answers

Which of these scenarios describes an antagonistic drug interaction?

<p>Administering one drug that blocks the effect of another (A)</p> Signup and view all the answers

When combining nitrous oxide with sevoflurane in anesthesia, which type of drug interaction is demonstrated?

<p>Synergistic effect (B)</p> Signup and view all the answers

Which outcome occurs when a positive allosteric modulator is present without the primary ligand?

<p>The receptor remains inactive (D)</p> Signup and view all the answers

What effect does the binding of propofol and fentanyl together have on a patient during sedation?

<p>They may enhance the respiratory suppression effect (B)</p> Signup and view all the answers

What does it mean if a drug does not travel into certain tissues?

<p>The drug will have no effect on those tissues. (A)</p> Signup and view all the answers

Where will students access the exam and when?

<p>On Canvas, after 9 a.m. the day of the exam. (B)</p> Signup and view all the answers

What feedback do students receive immediately after the exam?

<p>No feedback or preliminary results. (C)</p> Signup and view all the answers

What is the relationship between pKa and the ionization of a weak acid at physiological pH?

<p>At pH lower than pKa, the acid remains unionized (B)</p> Signup and view all the answers

Flashcards

Competitive Antagonism

When two drugs compete for the same receptor, the drug with higher affinity will bind more strongly and produce a greater effect.

Antagonist

A drug that binds to a receptor and prevents its activation by an agonist, but doesn't produce any effect itself.

Agonist

A drug that binds to a receptor and triggers a response.

Non-Competitive Antagonism

A type of antagonist that binds to a receptor at a site different from the agonist binding site, preventing agonist binding and action.

Signup and view all the flashcards

Drug Affinity

The strength of a drug's attraction to a receptor.

Signup and view all the flashcards

Drug Efficacy

The ability of a drug to produce a physiological effect when it binds to a receptor.

Signup and view all the flashcards

Beta Blocker

A drug that blocks the effects of beta-adrenergic receptors, which are found in the heart and blood vessels.

Signup and view all the flashcards

Sympathomimetic

A drug that increases the levels of catecholamines, such as epinephrine and norepinephrine, in the body.

Signup and view all the flashcards

Inverse Agonist

A type of drug that can bind to a receptor and reduce its activity below its normal baseline level.

Signup and view all the flashcards

Dual Function Antagonist

Drugs like naloxone that have both antagonist and inverse agonist effects.

Signup and view all the flashcards

Allosteric Modulator

A type of modulator drug that binds to a receptor at a different site than the agonist, changing the receptor's response to the agonist. This can occur by either enhancing or inhibiting the receptor's activity.

Signup and view all the flashcards

Positive Allosteric Modulator (PAM)

An allosteric modulator that enhances the effect of the agonist.

Signup and view all the flashcards

Negative Allosteric Modulator (NAM)

An allosteric modulator that reduces the effect of the agonist.

Signup and view all the flashcards

Additive Effect

The combined effect of two drugs is equal to the sum of their individual effects.

Signup and view all the flashcards

Synergistic Effect

The effect of two drugs together is greater than the sum of their individual effects.

Signup and view all the flashcards

Antagonistic Effect

One drug cancels or reduces the effect of another drug.

Signup and view all the flashcards

Volume of Distribution

The extent to which a drug is distributed to different tissues in the body.

Signup and view all the flashcards

Limited Distribution

When a drug is not distributed to tissues where it won't have an effect, it's said to have limited distribution.

Signup and view all the flashcards

Exam Scope

The exam will focus on the content covered in the PowerPoints and lectures. Materials not discussed in these resources may not be on the exam.

Signup and view all the flashcards

Exam Password

The exam password will be provided on Canvas a short time before the test begins.

Signup and view all the flashcards

Exam Results

The results of the exam will be uploaded to Canvas after the exam is graded.

Signup and view all the flashcards

Exam Platform

The exam will be taken on ExamSoft, a digital platform.

Signup and view all the flashcards

Exam Availability

The exam will be available until the weekend, and the time limit will be announced.

Signup and view all the flashcards

Grade Release Time

The time it takes to release exam grades after the completion of grading. It is usually done quickly, within a reasonable time frame.

Signup and view all the flashcards

What is C50?

The concentration of a drug, usually represented on the x-axis of a dose-response curve. It indicates the amount of drug needed to elicit a certain response.

Signup and view all the flashcards

What is efficacy? And what part of the curve represents it?

The ability of a drug to produce a maximal effect, regardless of the dose. It is represented by the plateau on the dose-response curve.

Signup and view all the flashcards

How is drug potency related to receptor affinity?

The strength of a drug's attraction to a receptor. A higher affinity means the drug binds more readily to the receptor.

Signup and view all the flashcards

What is LD50/ED50?

The ratio of the lethal dose (LD50) to the effective dose (ED50). This indicates the safety margin of a drug.

Signup and view all the flashcards

What is drug potency?

The measure of how much drug is needed to produce a certain level of effect. A highly potent drug produces a strong effect at low concentrations.

Signup and view all the flashcards

What does the slope of a dose-response curve represent?

The slope of the dose-response curve represents the number of receptors occupied by the drug at different concentrations.

Signup and view all the flashcards

What is a racemic mixture?

A mixture of two enantiomers, which are mirror images of each other. These mirror images often have different pharmacological effects.

Signup and view all the flashcards

What is an agonist?

A drug that binds to a receptor and activates it, producing a biological response.

Signup and view all the flashcards

What is pKa?

A measure of the tendency of a weak acid to donate a proton (H+). Lower pKa values indicate stronger acids.

Signup and view all the flashcards

What is the significance of the pKa of a weak acid?

The pH at which a weak acid is 50% ionized and 50% non-ionized.

Signup and view all the flashcards

What is passive diffusion?

The movement of a substance across a membrane from an area of high concentration to an area of low concentration.

Signup and view all the flashcards

What is the blood-brain barrier?

The barrier that separates the blood from the brain, protecting the brain from harmful substances.

Signup and view all the flashcards

What is ionization?

The tendency of a substance to exist in its ionized form. Higher pH favors the ionized form of an acid.

Signup and view all the flashcards

How does the pKa of a weak acid affect its entry into the brain?

The ability of a weak acid to cross the blood-brain barrier depends on its ionization state. Non-ionized forms of weak acids cross more easily than ionized forms.

Signup and view all the flashcards

How is the ionization state of a weak acid related to its pH?

At a pH higher than the pKa, a weak acid will be more ionized. At a pH lower than the pKa, a weak acid will be more non-ionized.

Signup and view all the flashcards

Why would a weak acid with a pKa of 9 have a greater fraction of its ionized form in the plasma compared to a neuron?

Due to a slightly higher pH in plasma compared to the neuron, a weak acid with a pKa of 9 would have a greater fraction of its ionized form in the plasma than in the neuron.

Signup and view all the flashcards

Study Notes

Agonist and Antagonist Interaction

  • Agonists are substances that bind to receptors and trigger a response.
  • Antagonists bind to receptors but do not trigger a response. They prevent agonists from binding and thus block the response.
  • Full agonists produce a maximal response.
  • Partial agonists produce a response that is less than maximal, even at maximal receptor occupancy.
  • Competitive antagonists bind to the same receptor as the agonist, competing for binding sites.
  • Non-competitive antagonists bind to a different site from the agonist, altering the receptor's shape and blocking agonist binding.
  • Irreversible competitive antagonists bind to the receptor and do not dissociate, permanently blocking the agonist's effect.

Receptor Occupancy and Efficacy

  • Efficacy is the ability of a drug to produce a desired effect.
  • Potency is the amount of drug needed to produce a certain effect.
  • Competitive antagonism decreases potency, but not necessarily efficacy.
  • Non-competitive antagonism decreases both potency and efficacy.

Real World Examples

  • Beta-blockers are competitive antagonists that obstruct norepinephrine from receptors, requiring increased norepinephrine for an effect.
  • Examples of using drugs in an operating room are given when dealing with beta-blockers, such as metoprolol and ephedrine.
  • Anesthetics and opioids, such as Narcan, can be antagonists that compete with the agonist leading to a lesser effect from the agonist.

Inverse Agonists

  • Inverse agonists bind to the receptor and produce the opposite effect of the agonist.
  • Inverse agonists decrease constitutive activity of the receptor.

Allosteric Modulators

  • Allosteric modulators bind at a different site on the receptor, altering the receptor's conformation and influencing agonist binding and effects.
  • They can either increase or decrease the agonist's effect.

Synergistic and Antagonistic Effects

  • Synergistic effects occur when two drugs together produce a greater effect than the sum of their individual effects.
  • Antagonistic effects occur when two drugs together produce a weaker effect than the sum of their individual effects.

Hormonal Differences

  • Females may have a higher sensitivity to muscle relaxants and may emerge from anesthesia more quickly than males.
  • Hormonal changes can influence drug responses.

Tachyphylaxis

  • Tachyphylaxis is a rapid decrease in the response to a drug upon repeated administration.
  • This is caused by reduced receptor availability or changes in receptor function due to repeated agonist exposure.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Lecture 2 -2 PDF

Description

Test your knowledge on pharmacological concepts related to dose-response relationships, including drug potency, efficacy, and receptor interactions. This quiz covers essential terms and definitions necessary for understanding pharmacodynamics and drug actions.

More Like This

Dose-Response Curve
3 questions

Dose-Response Curve

Dose Response Curve
14 questions

Dose Response Curve

CredibleOcean avatar
CredibleOcean
Dose-Response Curve
11 questions

Dose-Response Curve

CredibleOcean avatar
CredibleOcean
Drug Actions and Potency Comparison
20 questions

Drug Actions and Potency Comparison

SpiritualHonor avatar
SpiritualHonor
Use Quizgecko on...
Browser
Open
Browser
Browser