Pharmocology Flashcards
What is absorption?
The movement of a drug from its site of administration into the systemic circulation
What is adverse effect?
General term for an undesirable and potentially harmful drug effect
What does ADME stand for?
Absorption
Distribution
Metabolism
Elimination
What is affinity?
The ability of thedrugto bind to a receptor
What is Kd?
Attraction with which a drug binds to the receptor and it is the concentration at which half of all the receptors are occupied by the drug
Is the affinity greater or lower with a low Kd?
Greater
What is a full agonist?
A drug capable of eliciting a maximal response as it displays full efficacy at that drug receptor
What is inverse agonist?
A drug capable of eliciting a maximal response as it displays full efficacy at that drug receptor.
What is partial agonsist?
Drugs that bind to and activate a given receptor, but only have partial efficacy at the receptor relative to the agonist
What is antagonist?
A receptor ligand or drug that blocks, dampens or inhibits an agonist-
mediated response rather than provoking a biological response itself upon binding to a receptor
What is a competitive antagonist?
A receptor ligand or drug that binds to the same
binding site as an endogenous ligand or agonist but without activating the
receptor. Agonists and antagonists effectively ‘compete’ for the binding site on the receptor
What is a non-competitive antagonist?
A receptor ligand or drug that binds to an allosteric (non-agonist) site on a receptor to prevent the activation of that receptor
What is an allosteric modulator?
A substance which indirectly influences (modulates) the effects of an agonist or inverse agonist at a target protein
What is Bmax?
The maximum amount of drug which can bind specifically to receptors in a
membrane preparation. If one drug molecule binds to each receptor it acts as an indication of the concentration of receptors in the tissue
What is EC50?
The molar concentration (EC 50 ) of an agonist that produces a 50% response of the maximum possible response for that agonist
What is ED50?
Dose (ED 50 ) of drug that produces 50% of its maximum response or effect.
What is efficacy?
Used to describe agonist responses in relation to receptor occupation
What is the first pass effect?
-Orally administered drugs that are
absorbed into the circulation, must pass the liver first prior to becoming
available to the rest of the body.
What is LD50?
The dose of a drug that causes death in 50% of the animals tested.
What is a ligand?
Chemical compound, endogenous or exogenous, that binds to
a pharmacologically relevant binding site.
What is pharmacodynamics?
The biochemical and physiological effects of drugs, particularly those that define the drugs mechanism of action on the body.
What is pharmacokinetics?
The absorption, distribution, metabolism, and excretion (ADME) of
bioactive drugs following their administration to higher organisms
What is potency?
Compares the ability of drugs to produce a
given effect.
What is prodrug?
A drug administered in an inactive form that is metabolised in the body to an active form
What is a drug?
Chemical substance of known structure, when administrated to a living organism produces a biological effect
What are categories of drugs?
- Physiological system
- Therapeutic group
- Chemical properties
What is the most prescribed drug in USA 2017?
Lisoprinal
What is the most prescribed drug in UK 2017?
Atorvastatins
What is the biggest man-made medical disaster ever?
Thalidomide
What are relentlessly incurable diseases?
- Alzheimers disease
- Glioblastoma
- Common cold
- Rabies
- Diabetes
Why are Alzheimers disease/Glioblastoma/common cold/Rabies/Diabetes so difficult to treat?
- Genetic requirement for increased hormone production
- Once established, virus is unstoppable
- Disease mechanism undetermined
- Pathogen mutates too quickly
What are the routes of drug administration?
- Oral
- Rectal
- Intravenous
- Intramuscular
- Perecutaneous
- Nasal
- Inhalation
- Sublingal
What are contributing physiological to absorption of oral drugs?
- Gut content
- GI motility
- Splanchnic blood flow
- Drug formation
How do drugs pass membranes?
- Simple diffusion
- Facilitated diffusion through aqueous channels
- Carrier-mediated transport
What are different types of carrier-mediated transport?
- ATP-dependent: active
- ATP-independent: passive
What helps the movement of drugs across a membrane?
- High concentration gradient
- Low molecular weight
- Low degree of ionisation
- Lipid solubility
What is bioavailability?
Describe how much of the orally given drug makes it into circulation in its active form
What must happen to a dose when converting from intravenous to oral route from with a bioavailability of 50%?
Double the dose
What is pro of the route of oral administration?
Easy to administer
What is con of the route of oral administration?
Subject to first pass effect
What is pro of the route of intravenous administration?
100% Bioavailability
What is con of the route of intravenous administration?
Enters tissues rich in blood vessels first
What is pro of the route of rectal administration?
Can be used in vomiting patients
What is con of the route of rectal administration?
Bioavailability varies depending on blood supply
What is pro of the route of intrathecal administration?
Cross the blood brain barrier
What is con of the route of intrathecal administration?
Difficult to administer
What is pro of the route of inhalation administration?
Local effect, very fast
What is con of the route of inhalation administration?
Not suitable for large molecules, can leak into systemic blood
What is pro of the route of percutaneous administration?
Not subject to first pass effect
What is con of the route of percutaneous administration?
Bioavailability varies depending on subcutaneous muscle and fat
Describe alcohol absorption on an empty stomach:
- Some absorbed in stomach
- Most absorbed rapidly in small intestine
Describe alcohol absorption on a full stomach:
- Fatty meal reduce blood alcohol concentration up to 50%
- Pyloric sphincter is closed
- Alcohol absorbed more slowly in stomach