Hardcastle case study 2 and 3 Flashcards
(34 cards)
What is gastric acid and what does it do
gastric acid is HCl and is essential for digestion. Breaks down proteins, fats and starches
What does excess stomach acid lead to
can cause heartburn, or acid reflux. Prolonged excess acid can damage the stomach or intestinal mucosa can result in ulcers
What do antacids do and give examples
antacids neutralise excess HCl
Al(OH)3, Mg(OH)2, CaCO3, NaHCO3
What receptors does histamine acts on and how does it work
histamine acts at the H2-receptor on parietal cell. Activates H+/K+ ATPase to release H+ ions which produces more HCl
Why can we not use antihistamines to treat excess acid production
antihistamine blocks histamine at the histamine H1-receptor, which is different to the H2 receptor. So antihistamine is not effective for blocking gastric acid secretion
What is the proposed target for gastric acid production
histamine H2-receptor
What is gastric acid production stimulated by
- histamine at H2 receptor
- acetylcholine at M3 receptor
- gastrin at CCK2 receptor
What is the problem with H2-antagonists
they are competitive inhibitors so they are effective but it has a short duration of action
What can we do to reduce gastric acid secretion instead of using H2-antagonists
The gastric H+/K+ ATPase is the final step. If we inhibit the ATPase we will stop the production of HCl
What drug is used to inhibit the gastric H+/K+ ATPase
omeprazole
What is the activated form of Omeprazole and what does it do
the activated species of Omeprazole is called sulfenamide. And it acts as an irreversible inhibitor
What type of drug is Omeprazole
prodrug
What is a prodrug
a prodrug is an inactive compound which is converted to an active drug in vivo
How does the activated Omeprazole drug interact with
Nucleophilic attack from an active site cysteine at the sulfur forms a covalent S-S bond with the drug
- irreversible enzyme inhibitor
What is the S enantiomers of Omeprazole
Esomprazole
Compare and contrast the S and R isomer of Omeprazole
S-enantiomer is more potent and more orally available than the R-enantiomer. They have different metabolisms and different safety profiles
What does positive symptoms mean
symptom which adds something
What does negative symptoms mean
symptoms which take away something
What are the current treatments for schizophrenia
psychopharmacological drugs
What was the first antipsychotic
chlorpromazine
How does chlorpromazine work
Chloropromazine is a potent dopamine D2 antagonist.
What is dopamine D2
dopamine D2 a G-protein coupled receptor
What is a G protein-couples receptor
set of receptors responsible for sensing extracellular message and transmitting them to cell
What is a full agonist
Activates receptor to a similar degree to the natural ligand
