Pharmacodynamics and Drug Interaction Quiz

Greetings

• Good morning, or good evening
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Topic 1: Pharmacodynamics

• Pharmacodynamics is a branch of pharmacology
• It describes the effects of drugs on the body
• It looks into the mechanism(s) of drug action

Topic 2: Drug-Body Interaction

• Drugs interact with the body in a dynamic way
• The body responds to the presence of drugs
• Pharmacokinetics studies the drug's movement within the body.
• Pharmacodynamics studies the drug's impact on the body.

Topic 3: Therapeutic Window

• A therapeutic window is an optimal dosage range.
• It produces the desired effect without toxicity.
• It avoids treatment failure.

Topic 4: Factors Affecting Drug Concentration at the Site of Action

• Dose is a key factor
• Pharmacokinetics (ADME) also influences drug concentration.
  • ADME stands for Absorption, Distribution, Metabolism, and Excretion.

Topic 5: Mechanisms of Drug Actions

• Drugs operate via two main mechanisms
  • Receptor-mediated action
  • Non-receptor-mediated action

Topic 6: Non-receptor Mediated Actions

• Some drugs work by interacting chemically.
• Examples include antacids (neutralize stomach acid), and osmotic diuretics/purgatives.
  • They rely on their physicochemical properties.

Topic 7: Receptor Mediated Actions

• Receptors are cellular macromolecules.
• Drugs bind to receptors to initiate an effect.
• The most important receptors are cellular proteins.

Topic 8: Drug Receptor Theory

• Drugs exert their effects by binding to receptors.
• Binding can either stimulate or inhibit receptor activity.

Topic 9: Sites of Receptors

• Receptors are located on cell membranes or inside cells.
  • Examples include adrenoceptors, cholinoceptors, and steroid receptors.

Topic 10: Receptor Functions

• Receptors have ligand (drug) binding domains.
• They have effector domains to propagate the message.

Topic 11: Ligand Binding (Drug Binding)

• Ligands (drug molecules) selectively bind to receptors.
• This binding is like a lock and key mechanism; the drug fits into the receptor to activate it.

Topic 12: Active Chemical Groups & Active Chemical Sites

• The active chemical groups on the drug interact with the active chemical sites on the receptor.
• This results in a drug-receptor complex.

Topic 13: Results of Ligand Binding with Receptors

• After binding, receptors can directly influence cellular targets or effector proteins.
• Receptors can also indirectly impact targets through signaling molecules called transducers.

Topic 14: What is a Transducer?

• Transducers are intermediate signaling molecules.
• Examples include enzymes and second messengers.
• Second messengers can manipulate, transport, or degrade small metabolites.

Topic 15: Second Messenger Function

• Second messengers transmit information throughout the cell.
• This propagation leads to the desired effect.

Topic 16: Receptor Types (Signaling Mechanisms)

• Ionotropic receptors directly interact with ion channels on the cell membrane.
  • This interaction leads to ionic transport when a drug binds.
  • Examples include nicotinic cholinergic receptors.

Topic 17: G Protein-Coupled Receptors (GPCRs)

• GPCRs are large membrane proteins.
• They have an extracellular region for ligand binding and an intracellular for G-protein binding.

Topic 18: G Proteins

• G proteins act as molecular switches inside cells.
• They relay signals from external stimuli to the cell's interior.

Topic 19: G Protein-coupled receptors (GPCRs) Role

• Proteins within the cell membrane relay information.
• The information is transmitted from extracellular substances to intracellular G-protein.
• GPCRs regulates various biochemical functions.

Topic 20: G Protein-coupled Receptors (GPCRs) Composition

• Extracellular parts comprise an amino terminus and binding loops.
• Transmembrane intermediate regions.
• Intracellular regions are at the carboxy terminus, protruding into the cytoplasm.
• G-proteins (intracellular) consist of α, β, and γ subunits.

Topic 21: GPCR Subunits

• GPCRs have specific subunits (α, β, and γ) to regulate their function.
• GTP allows activation of the complex

Topic 22: GPCRs N-terminus and C-terminus

• N-terminus is the amino terminus
• C-terminus is the carboxyl terminus

Topic 23: Examples of GPCRs

• Muscarinic cholinergic receptors
• Adrenergic and dopaminergic receptors.
• Serotonin (5-HT) receptors
• Opioid receptors

Topic 24: Diseases Involving GPCRs

• Type 2 diabetes mellitus (T2DM)
• Obesity
• Depression
• Cancer
• Alzheimer's disease

Topic 25: GPCR Acting Drugs

• Histamine receptor blockers
• Opioid agonists
• Beta-blockers
• Angiotensin receptor blockers

Topic 26: GPCR Acting Agonists

• Mu-opiate agonists
• Beta2-adrenergic agonists.
• Alpha2-adrenergic agonists

Topic 27: G protein families

• G proteins have four distinct families (Gs, Gi, Gq, and G12).
• These variations are based on the second messenger systems they activate.

Topic 28: G protein classification

• G proteins are categorized based on their alpha (α) subunit:
• G₁, G5, G12/13 and Gq

Topic 29: Effects of Drug Binding to G-protein Coupled Receptors

• Binding activates G-proteins
• This leads to affecting effector proteins.
  • Examples include adenyl cyclase and phospholipase.
• Intracellular second messengers like cAMP, cGMP, IP3, and Ca++ are affected.

Topic 30: Receptors Linked to Tyrosine Kinase

• These are transmembrane receptors with two domains.
  • An extracellular domain for ligand binding.
  • A cytoplasmic domain with tyrosine kinase enzymes.
• Binding stimulates the tyrosine kinase, resulting in target protein phosphorylation.
• Insulin receptors are an example

Topic 31: Tyrosine Kinase Receptor Function

• Tyrosine kinase receptors are proteins on cell surfaces.

Topic 32: Receptors Linked with Tyrosine Kinase Diagram

• Active and inactive forms exist within the system
• There is interaction between the extracellular domain of ligand and the ligand itself

Topic 33: Intracellular Receptors

• These receptors exist inside the cell.
• They don't associate with the plasma membrane.
• Lipid-soluble ligands can cross the cell membrane to interact with these receptors.
  • Examples include steroid hormones, thyroid hormone and Vitamin D

Topic 34: Intracellular Receptor Diagram

• The receptor and ligand complex move into the cell nucleus to bring about an effect

Topic 35: Summary Table of Receptor Types

• Includes ligand-gated ion channels, G protein-coupled receptors, enzyme-linked receptors, and intracellular receptors.
• Presents subtypes of significant examples and their impact.

Test your knowledge on pharmacodynamics, drug-body interaction, and therapeutic windows with this quiz. Explore how drugs affect the body and the factors that influence their concentration at the site of action. Ideal for students in pharmacology studies.