Flashcards in Pharmacology Deck (61)
What a drug does to the body
What a body does to the drug (absorption, distribution, eliminations etc.)
They ability of an agonist to evoke a response
Higher efficacy = larger response
The strength of association between agonist and its receptor
Greater affinity = greater duration of binding
The concn of agonist that results in a half maximal response (i.e. 50% of receptors are occupied)
Agonist A requires 0.01 concn to elicit a response.
Agonist B requires 0.05 concn to elicit a response.
Agonist A is more ____ than agonist B.
In the presence of a competitive antagonist, EC50 is unchanged. True/False?
EC50 increases (need to increase concn of agonist to get response)
Both the ionised and unionised form of a drug readily diffuse across the lipid bilayer. True/False?
Only the unionised form does
The pH at which 50% of a drug is ionised and 50% is unionised
Henderson Hasselbach Equation
pH = pKa + log[A-]/[HA]
pKa - pH = log[HA]/[A-]
FOR WEAK ACIDS ONLY
Increasing the pH of an acidic drug causes it to become less ionised. True/False?
It becomes more ionised (acid drugs are less ionised in an acid environment)
Administration routes that by-pass first pass metabolism are...
Vd = volume of distribution = ?
Volume in which a drug is dissolved
Dose given/Plasma Concn
Vd less than 5L suggests...
Drug is contained in vascular compartment
Vd less than 15L suggests...
Drug is restricted to extracellular water
Vd greater than 15L suggests...
Drug is in total body water
Efferent signals travel _________ the CNS
Sympathetic preganglionic NT is?
Sympathetic postganglionic NT is?
Parasympathetic pre and post ganglionic NT is acetylcholine. True/False?
Sympathetic outflow is craniosacral. True/False?
Preganglionic neurone of sympathetic chain is long. True/False?
Short - preganglionic neurone of parasympathetic chain is long as ganglions are usually embedded in the target organ
Location of cranial parasympathetic ganglia in the head and neck
C3, C7, C9, C10
Parasympathetic stimulation decreases force of heart contraction. True/False?
Has no effect on force of contraction, but does decrease heart rate
Components of a G-protein
α (contains guanine nucleotide binding site)
β + γ complex
GP couples with receptor to increase affinity for GDP. True/False?
Affinity for GDP decreases and it eventually dissociates, increasing affinity for GTP to bind on α subunit
M1 G-protein coupled receptor is G_
Causes ___ acid secretion in stomach
M2 G-protein coupled receptor is G_
Causes ___ heart rate
M3 G-protein coupled receptor is G_
Causes ___ of airways; ___ of vasculature