Pharmacodynamics Flashcards
Learn what LAS specific drugs do to the body
1
Q
What is an Agonist?
A
A drug that binds to a receptor to stimulate a response
2
Q
What is an Antagonist?
A
A drug that binds to a receptor to block stimulation
3
Q
Adrenaline
A
- It’s a sympathomimetic
- Has positive inotropic (cardiac contraction) and chronotropic (affecting rate) effects
- Agonist at both alpha- & beta-adrenergic receptors (a1, ß1 & ß2 receptors):
- a1 & ß1 → (1) heart
- ß2 → (2) lungs
4
Q
Amiodarone Hydrochloride
A
- Class III antiarrhythmic
- Primary effect is to block potassium channels
- does also block sodium and calcium too
- Prolongs phase 3 of the cardiac action potential
5
Q
Aspirin
A
- Blocks COX 2 which is used in the synthesis of thromboxane (a product made by platelets to make blood clot)
- Aspirin inhibits platelet activation so it’s an antiplatelet
6
Q
Atropine Sulfate
A
- An acetylcholine (Ach) antagonist (anticholinergic)
- also antimuscarinic agent
- Blocks the action of Ach at the SA node
- SA node will revert to its normal rhythm of 60-100 (normocardic)
7
Q
Chlorphenamine
A
- Antihistamine - H1 receptor antagonist (tech. inverse histamine agonist)
- Also an anticholinergic
- Histamine release due to inflammatory response in anaphylaxis has caused loss of tone in blood vessels
- Binds to H1 receptor blocking action of endogenous histamine
- Prevents further histamine release but will not reverse loss of vascular tone that has already occurred
8
Q
Diazepam
A
- Anticonvulsant
- Benzodiazepine - sedative & hypnotic
- CNS depressant
- Anxiolytic
- Enhances GABA post synaptically (agonist)
- GABA is the primary inhibitory neurotransmitter of the CNS
9
Q
Glucose
A
- Carbohydrate which helps produce energy and heat
10
Q
Glyceryl Trinitrate (GTN)
A
- Potent vasodilator as the body converts it to nitric oxide
- Relaxes inner muscles of the blood vessels, causing vessels to widen
- this reduces after-load and pre-load
- This will the increase blood flow and lower blood pressure
11
Q
Hydrocortisone
A
- Works at cortisol receptor sites all over the body
- Glucocorticoid with anti-inflammatory properties
- reduce inflammation in asthma & anaphylaxis
- reduce overall length of asthma attack
- reduce likelihood of biphasic response in anaphylaxis
- In adrenal crisis it mimics action of cortisol (steroid hormone) which is lacking during crisis
12
Q
Ibuprofen
A
- Blocks cyclooxygenase (COX) 1 & COX 2
- COX enzymes are responsible for creating a hormone like substance called prostaglandins
- Prostaglandins produced by COX 1 responsible for producing the lining of the stomach
- Prostaglandins produced by COX 2 responsible for inflammation and fever
- Nonsteroidal anti-inflammatory drug
- Also classed as an analgesic and antipyretic
13
Q
Ipratromium Bromide
A
- Antagonist at muscarinic receptors in the lungs
14
Q
Morphine
A
- works on CNS binding to same receptor sites as our endogenous (naturally occuring - endorphins, dynorphins & enkephalins) opioids
- agonist at mu (best effect), kappa & delta receptors
- receptors are found in the stomach, brain & spine
- binding of morphine to receptors blocks the transmission of nociceptive signals
- activates signalling of pain-modulating neurons in the spinalcord and inhibits transmission from primary afferent nociceptors to the dorsal horn sensory projection cells
15
Q
Ondansetron
A
- Reduces activity of the vagus nerve, which de-sensitizes the chemoreceptor trigger zone (vomiting centre) in the medulla oblongata
- Blocks serotonin (5HT) receptors - specifically 5HT3
