DRUGS Flashcards
what medicines are typically used to induce mydriasis?
tropicamide
phenylephrine
what is the mechanism of action of tropicamide?
- muscarinic (M3) antagonist
- stops ACh binding to M3 receptors
- stops circular muscle contraction
- stops pupil constriction
what is the mechanism of action of phenylephrine?
- alpha-adrenoceptor agonist
- binds to receptors and causes radial muscles of iris to contract
- increases pupil size
what % of tropicamide is standard?
0.5%
what % of phenylephrine is standard?
2.5%
what % is the standard does of pilocarpine?
2%
what medicines can be used to induce myopia?
pilocarpine
list 3 tricyclic ADs
desipramine
amitriptyline
clomipramine
desipramine, amitryptyline, clomipramine are all what type of antidepressant?
tricyclic
list 3 SSRIs
fluoxetine
paroxetine
flucoxamine
sertraline
citalopram
fluoxetine, paroxetine, flucoxamine, sertraline, citalopram - what type of antidepressant are these?
SSRIs
list 2 SNRIs
venlafaxine
duloxetine
venlafaxine and duloxetine are examples of what type of antidepressant?
SNRIs
what does each antidepressant block?
tricyclics and SNRIs - SERT and NAT
SSRIs block only SERT
what is the mechanism of action of propofol?
GABA agonist - increases inhibitory effect
what is the volume of distribution of propofol?
- 60L/kg
what is the MOA of isoflurane?
- reduces gap junction channel opening times
- alters tissue excitability
- induces muscle relaxation
what is the MOA of fentanyl?
- agonist of mu opioid receptor
- inhibits adenylate cyclase
- = downregulation
- hyperpolarises cell and inhibits nerve activity
what is a typical dose of fentanyl?
0.05mg/mL IV
what is the MOA of suxamethonium?
- depolarising neuromuscular blocker
- mimics ACh but not rapidly hydrolysed
wh
what is the MOA of atracurium?
- non-depolarising neuromuscular blocker
- antagonist of ACh sp. at nicotinic receptors
what is the MOA of neostigmine?
- inhibits AChE
- prolongs action of ACh
- increases muscular contraction and reverses muscle relaxants
what is hte MOA of atropine/glycopyrrate
- antagonise muscarinic receptors
- inhibit cholinergic transmission
- decreases bradycardia risk from neostigmine
what is the MOA of mannitol?
- increases blood plasma osmolarity
- increases flow of water from tissues
- decreases ICP
what is the MOA of depakote?
- folate antagonist
- blocks reuptake of GABA into glia cells
what is the MOA of paracetamol?
- selective COX2 inhibitor
- Inhibits production of prostaglandins (anti-inflammatory) and thromboxanes (anti-platelet)
what is the typical dosage of paracetamol
0.5-1g every 4-6 hours to max of 4g daily
what is the MOA of ibuprofen?
Weak COX 1 inhibitor
what is the typical dosage of ibuprofen
300-400g 3-4 times daily to max of 2.4g