1st lecture - pharmacodynamics Flashcards
Pharmacodynamics explains
where, how and why a medicinal product acts;
explains the mechanism of action of the medicinal product
“biological effects”
the Primary pharmacodynamic reaction is
the molecular mechanism of action of a medicinal product.
the Secondary pharmacodynamic reaction is
the change in the physiological functions of organs due to the effect of the drug.
A medicinal product can impact the cells by: (4)
By changing the physicochemical conditions in the extracellular environment
By impacting the ion channels of membranes
By impacting cell metabolism by changing the enzyme systems or DNA and RNA activity
By acting on regulatory (neural, humoral) processes
define pharmacon
A medicine or drug.
The binding of a pharmacon with cell substrate achieves
the treatment effect
The binding of pharmacon with blood plasma or tissue proteins, lipids achieves what
deposition/ depot formation
The binding of pharmacon with Specific antibodies achieves
depot formation
The binding of pharmacon with Enzymes achieves
metabolism of the medicinal product or the activity level of enzymes changes
explain what receptors are
biochemical components of the cell (a molecule or a polymeric structure on the surface or inside a cell) that reacts specifically with a drug molecule, transmitting its action to the cell.
explain what acceptors are
Acceptors are the remaining binding locations after the receptors; so the acceptors are related to the deposition of the drug, its deactivation or transport.
e.g. plasma proteins “storing” substances
Each receptor has its own
internal reaction partner or endogenous receptor ligand, which performs the role of physiological mediator.
The biological purpose is unrelated to medicinal products.
Endogenous neurotransmitters often bind to
more than one type of receptor.
This allows the same signaling molecule to produce a variety of effects in different tissues.
Classification of receptors by endogenous receptor ligand (5)
Acetylcholine – cholinoreceptors
Dopamine – dopamine receptors
Histamine - histamine receptors
Noradrenaline – adrenoreceptors
Serotonin – serotonin receptors
Classification of receptors By drug (ligand is unknown) (min 3)
Opioid receptors
Benzodiazepine receptors
Barbiturate receptors
Receptor agonist is
a pharmacon that has the same effect as an endogenous ligand (mimetics)
Receptor antagonist is
a pharmacon that has the opposite effect as an endogenous ligand (blockers)
mimetics are
receptor agonists
blockers are
receptor antagonists
explain Point of attack
the place where the reaction between the pharmacon and receptor occurs
explain Effector organ
the organ where the point of attack is located (the place where the reaction between the pharmacon and receptor occurs)
A receptor may be located on
a cell membrane, cytoplasm, nucleus, enzyme molecule, etc.
An excessive increase in concentration of drug will only
increase the side effects and not the treatment effect.
What is effective concentration?
effective concentration (EC) is the minimum dose or concentration of a drug that produces a biological response.
explain Therapeutic window
Also known as therapeutic amplitude or index
is the difference between a therapeutic and a toxic dose
the higher the therapeutic index, the ?
safer the drug
(describes the gap between effective dose and toxic dose)
explain Secondary pharmacodynamic effect
the change in the function of organs, organ systems or the organism as a whole due to a drug.
It follows the primary pharmacodynamic effect.
explain Drug’s affinity
its ability to bind a receptor.
Determines the concentration of drug required to form a significant number of drug-receptor complexes that are responsible for drug action.
explain drug efficacy
the drug’s ability to initiate changes that lead to the production of responses.
explain drug potency
the concentration of drug required to achieve a given effect.
Drug interaction examples (5)
increase in potency
can inhibit
competition for the same receptors
Insoluble compound formation leading to no absorption.
Pharmacokinetic interaction – a drug changes the absorption, distribution, metabolism, secretion of another drug.
Side effects are
(in most cases) undesired effects occurring concurrently with the therapeutic effect.
Sometimes used as treatment effects
e.g. aspirin (NSAID) used for anticoagulation.
Contraindications are
conditions (a situation or factor) that serve as a reason not to take a certain medical treatment due to the harm that it would cause the patient
difference between pharmacokinetics and pharmacodynamics?
pharmacokinetics is the movement of drugs through the body, whereas pharmacodynamics is the body’s biological response to drugs.
in what part of a synapse does mediator synthesis occur?
presynapse
in what part of a synapse is the mediator place of action?
postsynapse, receptors
what is the difference between drug efficacy and drug potency?
Efficacy is the ability of a drug to elicit a physiologic response when it interacts with a receptor.
Potency is the amount of drug needed to produce a certain response. In general, potency is denoted as the median effective concentration/dose so refers to the concentration (EC50) or dose (ED50) of a drug required to produce 50% of that drug’s maximal effect.
