Drugs Flashcards
What does lansoprazole do and what is it prescribed for? (GERD)
Lansoprazole reduces the amount of acid your stomach makes.
It is prescribed for indigestion, heartburn acid reflux and GERD
What is the mechanism of action of lansoprazole? (GERD)
Lansoprazole acts as a proton pump inhibitor. It targets H+/K+ ATPase, which is an enzyme that catalyses the final step in the acid secretion pathway in parietal cells. By inhibiting this gastric acid secretion is reduced.
What are antacids and what do they do? (GERD)
Antacids are a type of over the counter medication to neutralise stomach acid, e.g Gaviscon
They are a combination of salts
Not a long term solution
What is the mechanism of action of antacids? (GERD)
The antacids act as a weak base to neutralise and react with the HCL in the stomach to form a salt + water. Decreasing conc of H+ ions and acidity. Due to the increase in pH pepsin (a proteolytic enzyme) is inhibited and only exists as the inactive form of pepsinogen, preventing any autodigestion in acid reflux.
What are oral iron supplements and when are they prescribed? (ALL)
Oral iron supplements are also known as ferrous fumerate, which is an easily absorbed form of iron
They are prescribed and used to treat iron deficiency anaemia by increasing iron levels for adequate haemoglobin production.
What is dexamethasone? (ALL)
Dexamethasone is a type of corticosteroid, which is an anti-inflammatory agent
In low doses- anti-inflammatory
In high doses- immunosuppressant
What is the mechanism of action of dexamethasone? (ALL)
2 modes of action:
1) -Binds to the glucocorticoid receptor
- Inhibits nuclear factor kappa B ( which is a transcription factor that transcribes inflammatory cytokines)
- This inhibits pro-inflammatory signals
- Promotes anti-inflammatory signals
- Decreases vascular permeability and leukocyte migration
2) -Inhibits phospholipase A2 and COX enzyme, which together form inflammatory mediators
- reduces pro-inflammatory mediators
What is the mechanism of action of asparaginase? (ALL)
Asparaginase is an enzyme that breaks down the amino acid asparagine. ALL cells are unable to produce their own asparagine but need it to make functional proteins. Inhibiting the asparagine inhibits the cancer cell growth
What is the mechanism of action of vincristine? (ALL)
Part of a class of drugs known as vinca alkaloids
- Interfere with microtubule formation to prevent mitosis and cell replication
- Blocks the utilisation of glutamic acid to interrupt protein synthesis- inhibiting cell growth
What is the mechanism of action of mercaptopurine? (ALL)
Acts as an antineoplastic and immunosuppressant agent
- Blocks the synthesis of purine nucleotides to block DNA synthesis
- Incorporates into DNA as deoxy-thioguanosine and disrupts DNA replication - stopping cell replication/growth
What is the mechanism of action of methotrexate? (ALL)
Acts as an antineoplastic and immunosuppressant agent
-Inhibits the enzyme dihydrofolate reductase which prevents the synthesis of purine and pyrimidine nucleotides, inhibiting DNA/RNA synthesis- stopping cell growth
What is the mechanism of action of co-amoxiclav? (Sepsis)
A combination therapy containing amoxicillin and clavulanic acid.
- Amoxicillin is a broad-spectrum beta-lactam antibiotic
- Mimics the shape of the D-Ala-D-Ala dimer and irreversibly binds and blocks the active site
- Inhibiting transpeptidase, and blocking the synthesis of the peptidoglycan cell wall
- Leads to cell lysis
- The clavulanic acid inhibits beta-lactamase enzymes produced by bacteria to provide resistance to beta-lactam antibiotics
What is the mechanism of action of flucloxacillin? (Sepsis)
Flucloxacillin is a penicillin beta-lactam antibiotic
- Binds to specific penicillin-binding proteins (PBP’s) located inside the bacteria cell wall.
- Inhibiting the third and last stage of bacterial cell wall synthesis
- Leads to cell lysis by bacteria cell wall autolytic enzymes such as autolysins.
What is Picolax used for? (GI infection)
Picolax is used to treat constipation or as in this case to prepare the large bowel before colonoscopy or surgery
What is the mechanism of action of Picolax? (GI infection)
Contains 2 laxatives: sodium picosulfate which is a stimulant laxative and magnesium citrate which is an osmotic laxative
- Sodium picosulfate has no effect until metabolised by gut bacteria into its active compound BHPM, which stimulates increased peristalsis
- Magnesium citrate causes water to be drawn into the lumen which stimulates defecation