Lectures 6-10 Flashcards
What would a peak using the patch clamp technique represent?
open state receptors
What are inverse agonists?
The show affinity but negative efficacy
What are GABA(A) receptors?
ligand gated Cl- channels in the brain
What is benzodiazepine?
GABA(A) agonist
It increases the affinity of the GABA binding site for GABA
It hence increases openings
What is the significance of Glutamate-gated chloride receptors?
They’re common in the nervous system
They’re targeted by anti-parasitic drugs
What are competitive antagonists?
What effect do they have?
They bind reversibly at the site of the natural agonist
They produce a parallel shift to the right of the agonist dose
What is important about an SERD’s structure?
It reflects oestrogen’s structure
What is fulvestrant?
A selective oestrogen receptor degrader
What is the difference between biosimilars and generics?
Biosimilars are modelled after drugs using living organisms, where generics are synthetic drugs
Give three examples of drugs that use physio-chemical properties
General anaesthetics
Laxatives
Osmotic diuretics
Define drug potency
drug activity expressed in terms of the amount required to produce an effect of given intensity
What are cardiomyocytes used for?
Decreasing blood pressure
What is the therapeutic window?
the region between the toxic and effective drug concentrations
What is AVD?
Apparent Volume of Distribution
The volume of fluid to dilute the absorbed dose to the concentration found in plasma
AVD = dose/[plasma]
What is thiopentone
A short acting barbiturate, causing unconsciousness within 30-40 seconds
What are the stages of biotransformation?
1 - oxidation using cytochrome p450 transmembrane enzymes in the ER to form -OH groups
2 - conjugation (forms small soluble molecules)
What is a prodrug?
A drug with active metabolites
Which drugs are used in clinical trials?
those with the maximum potential of reaching the target
What are the names of the nuclei of the hypothalamus regulating posterior pituitary function?
paraventricular
supraoptic
What hormones are released by the anterior pituitary?
Growth hormone (GHRH)
FSH/LH (Gonadotropin RH)
Adenocorticotropic homrone (corticotropin RH)
Thyroid stimulating hormone (thyrotropin releasing hormone)
Prolactin
What connects the anterior pituitary to the hyopthalamus?
hypothalamic-hypophyseal portal system
What connects the posterior pituitary and the hypothalamus?
hypothalamic-posterior pituitary stalk
What suppresses GH?
hyperlgycaemia
What does ACTH do?(2)
stimulates the production of cortisol by the adrenal cortex
increases ACTH and CTH by positive feedback
WHy does testosterone and oestrogen production increase?
decreased sensitivity to them (as negative feedback would increase their production)
What hormones does the posterior pituitary secrete?
ADH - regulates blood water potential
Oxytocin - stimulates smooth muscle contraction in breast and uterine tissue
What normally causes hypotuitarism?
tumours or hormone deficiency
What does GH deficiency mean for children?
stunted growth
What does GH deficiency mean for adults?
abdominal obesity and decreased bone density
When would GH or testosterone supplements be taken?
GH - before bed
Testosterone - in the morning
How would you test for ACTH deficiency?
Short Synacthen testing
insulin test
glucagon test
(hypoglycaemia is a key presentation)
How is ACTH deficiency treated?
homrone replacement therapy (hyrdocortisone is metabolised into cortisol)
How is TSH deficiency presented?
Brachycardia
Skin irritation
What might cause polyuria?
Polydipsia
Renal failure
ADH deficiency
What is acromegaly?
GH hypersecretion usually caused by a pituitary adenoma
What is cushing’s syndrome?
corticotroph adenoma
What is the agonist for GABA(A)
diazepam
What is the antagonist for GABA(A)
flumanzenil
define absorption
the movement of a drug from its site of administration to the plasma
How would ion trapping move weak acids?
they would move from acidic environments to basic environments
What are modified release tablets?
They have a membrane that is selectively permeable to water
What is transit time?
absorption time availability
What are the 3 different types of drug administration?
Enteral (oral/rectal)
Parenteral (subcutaneous - IV)
Percutaneous (inhalation)
