Pharmacology Flashcards
Drugs interact with specific molecules in the body, such as receptors, enzymes, ion channels, and transporters. True/false?
True
What are the 2 main drugs types?
Agonists and antagonists
Interactions can either enhance (agonist) or inhibit (antagonist) the activity of the target molecule.
What is pharmacodynamics?
Pharmacodynamics is the drug’s biological effect and mechanism of action
.
What is pharmacokinetics?
Pharmacokinetics is body’s response to drugs.
What is drug affinity?
drug affinity applies to both agonists and antagonists, and is the binding/unbinding to cells.
What is drug efficacy?
Drug efficacy doesn’t apply to antagonists
Is the measure of drug activation and action
What is orthosteric vs allosteric binding?
Orthosteric, which bind at the active site; and allosteric, which bind elsewhere on the protein surface, and allosterically change the conformation of the protein binding site.
What are the 4 receptor types and their mechanisms of actions?
LGIC (ligand-gated ion channel) is induced by electrolyte transport.
GPCR (G-protein coupled receptors) is secondary mechanism with use of alpha and beta-gamma complex and ATP.
Kinase-linked receptors operate by binding of stimulus leading to phosphorylation or other mechanism on receptors, resulting in release of substitute proteins and causing effect.
Nuclear receptors act by hormone diffusing into the cell and nucleus, resulting in hormone response and transcription of genes (on and off)
What are the 4 factors that influence drug absorption?
solubility of the drug, chemical stability, lipid to water coefficient, degree of ionisation
What are the 9 different routes of drug administration?
PO (orally)
IM (intramuscular)
IV (intravenous)
Subcutaneous
Transdermal
Eye drop
Per rectum
Inhalation
Sublingual
Describe drug metabolism and the main site of action?
drug metabolism occurs by two steps.
Step 1 is oxidation, reduction and hydrolysis.
Step 2 is conjugation. Both occur in the liver
Describe the process of drug excretion and the main site of action?
Drug excretion occurs in the kidneys by glomerular filtration, active tubular secretion and passive reabsorption by diffusion.
What is elimination rate constant (Ke), and its relationship with changes in dosage?
elimination rate constant (Ke) is fraction of drug elimated per unit time.
Increased dosage doesn’t affect half life or Ke of the drug
What is clearance (CL) of a drug?
Volume of plasma cleared of drug in unit time
What are the effects of noradrenaline and epinephrine (sympathetic), noting the receptor action, effects on HR/contractility/conduction veolicity/duration of systole?
Noradrenaline and epinephrine both act on beta1 adrenoceptors.
This increases HR, contractility, conduction velocity and reduces duration of systole.
What is acetylcholine and it’s receptor? What effects does it have on HR, contractility and systole?
ACh is a postganglionic parasympathetic neurotransmitter that acts on muscarinic M2 receptors. This reduces HR, contractility and increases duration of systole