Pharmacology

• what is pharmacokinetics???

  is what the body does to a drug

  Absorption= when a drug is released from its formulation/admin site + enters the blood

  Distribution= movement of a drug once in blood

  Metabolism= body using the drug + giving off a byproduct

  Excretion= getting rid of byproduct
• what is pharmacodynamics???

  is what the drug does to the body

  how the drug interacts with its target binding site/ receptor at molecular level
• what are 4 routes of drug administration?

  enteral/oral

  parenteral (subcutaneous, intravenous, intramuscular)

  mucous membrane

  transdermal
• what are advantages of enteral route?

  simple

  inexpensive

  painless

  no infection
• what are disadvantages of enteral route?

  slow delivery

  drug is exposed to harsh GI environment

  first-pass metabolism
• what is an example of enteral route?

  aspirin
• what are advantages of parenteral route?

  fast delivery

  high bioavailability

  no first-pass metabolism

  no harsh GI environment
• what are disadvantages of parenteral route?

  irreversible

  infection

  pain

  fear

  skilled personnel needed
• what is an example of parenteral route?

  morphine
• what are advantages of mucous membrane route?

  simple

  painless

  fast delivery to effected tissue

  no first-pass metabolism

  no harsh GI environment
• what are disadvantages of mucous membrane route?

  few drugs
• what is an example of mucous membrane route?

  asthma drugs
• what are advantages of transdermal route?

  simple

  painless

  good for continous/prolonged action

  no first-pass metabolism

  no harsh GI environment
• what are disadvantages of transdermal route?

  needs highly lipophilic drugs

  slow delivery

  can irritate
• what is an example of transdermal route?

  nicotine patches
• first pass metabolism?

  all orally administered drugs will face first-pass metabolism in liver

  in this process enzymes in the liver can inactivate a section of the ingested drug
• what is bioavailability of a drug?

  the amount of drug that is available for target organs
• how is bioavailability fraction of drug calculated?

  quantity of drug reaching system circulation/ quanitity of drug administered
• what is metabolism?

  enzymatic conversion of 1 chemical compound into another

  most drug metabolism happens in liver but some processes happen in gut wall, lungs, blood plasma

  depending on drug, metabolites can be therapeutic, harmful or inactive
• what are prodrugs?

  they dont produce pharmacological effects until they are chemically changed within body

  they are designed to improve bioavailability when drug itself is poorly absorbed from GI tract or cant cross blood brain barrier (BBB)
• Excretion?

  process that involves eliminating drugs from the body

  most drugs are metabolised first before being excreted

  it removes waste substances from body fluids + happens via urine formed in kidneys

  other routes from body include: bile, saliva, sweat, tears, faeces, milk, exhaled air
• receptors???

  found on surface of many different types of cells

  have a 3D specific structure, allows only substances that fit precisely to attach

  enables substances outside cell to influence activity in cell
• what is affinity/potency?

  ability of a particular chemical to bind to a receptor

  measure of a drug needed to produce a response
• what is efficacy?

  ability of a chemical to have an effect when it binds to a receptor

  maximal response a drug can produce
• what are agonists?

  drugs that occupy receptors + activate them

  they have affinity + efficacy
• what are antagonists?

  drugs that occupy receptors but DONT activate them

  they have affinity only
• what are ligand-gated ion channels?

  receptors that open or close in response to chemical signal/drug/ligand

  allows or blocks ion flow e.g. sodium + calcium

  binding by a ligand to extracellular side changes proteins shape + opens channels

  ion flow changes conc inside cell
• what are neuronal nicotinic receptors?

  found in central nervous system + autonomic ganglia

  they regulate processes such as transmitter release, cell excitability, neuronal integration
• what are GPCRs?

  consists of 7 alpha helices associated with protein on cytoplasmic side

  most common type of receptor

  acts as on/off switch

  if GDP binds to GPCR= inactive

  if GTP binds to GPCRT= active
• how does computer modelling of a drug's properties help?

  helps scientists at pharmaceutical + biotechnology companies filter out + abandon early on any candidate drugs that are likely to behave badly in the body

  saves significant time + money
• how does this computer software work?

  examine atom-by-atom structure of molecule

  determines how durable chemical is likely to be inside body's various chemical environments
• what is liver referred to as?

  "detoxifying" organ
• what does pharmacokinetics research use?

  tools of mathematics
• how can clinical pharmacologists calculate how a person is processing a drug?

  by measuring amounts of a drug in blood or urine

  this analysis involves mathematical equations- takes into account physical + chemical properties of the drug, total amount of blood in body, age and body mass of the person, health of persons liver + kidneys, other medicines the person is taking
• what are multidrug-resistance (MDR) pumps?

  microorganism ejection systems

  large proteins that weave through cell-surface membranes

  researches belives these pumps are used by microbes for self-defense

  pumps used to monitor incoming chemicals + spit out ones that can endanger the bacteria