MCBoM- Pharmacology drugs

Question 1

Salbutamol

Answer 1

For asthma, partial agonist of B2 receptors in lungs (though some action on B1 in heart
Can delay premature labour

Question 2

Hemicholinium triethylcholine

Answer 2

Competes with choline for uptake into presynaptic varicosity at the cholinergic synapse/NMJ, so less ACh made

Question 3

Vesamicol

Answer 3

Inhibits acetylcholine transport into vesicles at the cholinergic synapse

Question 4

alpha-latrotoxin

Answer 4

Depletes vesicles of acetylcholine at the cholinergic synapse

Question 5

Botulinum toxin

Answer 5

Inhibits exocytosis of ACh vesicles at the cholinergic synapse
Treats:
-blepharospasm (involuntary blinking, difficulty opening eyelids)
-focal spasticity
-spasmodic torticollis (neck move to one side)
-urinary incontinence
-improvement in appearance of wrinkles

Question 6

Acetylcholine, carbachol, muscarine, bethanechol

Answer 6

Parasympathomimetics

Non-selective muscarinic receptor agonists

Question 7

Cevimeline

Answer 7

Selective muscarinic 3 receptor agonist

Increases salivary and lacrimal secretion

Question 8

Atropine, hyoscine

Answer 8

Non-selective muscarinic receptor antagonists

Question 9

Pirenzepine

Answer 9

Selective muscarinic receptor antagonist for M1

Treats peptic ulcers

Question 10

Atropine

Answer 10

NON SELECTIVE MUSCARINIC ANTAGONIST

• premed for anaesthesia
• treats bradycardia, inhibits M3
• antispasmodic for gut (IBS etc), inhibits M3
• counteracts anticholinesterases (organophosphate/ nerve gas poisoning)

Question 11

Hyoscine

Answer 11

NON SELECTIVE MUSCARINIC ANTAGONIST
as with atropine +
motion sickness

Question 12

Ipratropium

Answer 12

-short term relief from asthma, inhibits M3 in lungs

M3 receptor antagonist

Question 13

Tropicamide cyclopentolate

Answer 13

-inhibit M3 receptors in eye causing mydriasis (dilation) and cycloplegia (no accomodation) for eye exams

Question 14

Tolterodine Darifenacin

Answer 14

-inhibits M3 receptors in detrusor muscle to treat urinary incontinence

Question 15

Histamine

Answer 15

Nicotinic receptor agonist

Question 16

Hexamethonium

Answer 16

Nicotinic receptor antagonist

lowers blood pressure as ganglia block

Question 17

Tubocurarine (curare)

Answer 17

NON DEPOLARISING NMJ BLOCKER
Slow onset (5 mins+)
Long duration (1-2 hours)
Not used clinically- side effects are hypotension, bronchoconstriction, tachycardia, anaphylactic reactions (form histamine release)

Question 18

Pancuronium, Vecuronium, Rocuronium

Answer 18

NON DEPOLARISING NMJ BLOCKER
Fast onset (2 mins)
30mins-1 hour duration
Used in intensive care for ventilating

Question 19

Atracurium, Cisatracurium, Mivacurium

Answer 19

NON DEPOLARISING NMJ BLOCKER
Fast onset (2 mins)
15-30mins duration
Histamine release

Question 20

Suxamethonium

Answer 20

ONLY DEPOLARISING NMJ BLOCKER IN USE
Fast onset (1-2 mins)
2-6 mins duration
Not broken down by acetylcholinesterase, by pseudocholinesterase instead
Muscle relaxant for tracheal intubation
Side effects:
-hyperkalaemia from K+ efflux, so heart disarrythmia and cardiac arrest
-bradycardia
-intraocular pressure rise
-prolonged paralysis with some patients (neonates, liver disease, substrates competing for cholinesterase)
-malignant hyperthermia with rare genetic condition

Question 21

Edrophonium

Answer 21

Short acting anticholinesterase
Brief association via weak electrostatic forces
Positively charged, so attracted to negative anionic site of acetylcholinesterase, occupies and blocks from acetylcholine (competes with)
Used to diagnose myasthenia gravis (will see return of muscle strength briefly)

Question 22

Neostigmine

Answer 22

Medium acting anticholinesterase
As with slow, but more slowly broken down by acetlycholinesterase
Used to treat myasthenia gravis
Used to reverse neuromuscular block by non-depolarising blockers
Pyridostigmine is the same, but less effect at parasympathetic synapses, so fewer side effects

Question 23

Dyflos

Answer 23

Irreversible anticholinesterase

Forms strong covalent bond with esteratic site of acetylcholinesterase leading to depolarising block

Question 24

Malathion, agricultural pesticides, nerve gases

Answer 24

Organophosphates.
Malathion- to kill head lice
Agricultural pesticides- to induce depolarising block, suicide
Nerve gases- in chemical warfare, induces depolarising block

Question 25

Ephedrine

Answer 25

Displacing agent, affecting noradrenergic transmission at postganglionic sympathetic synapses Competes with NA for uptake 1, so increased NA in synapse Used to reverse hypotension after spinal/epidural anaesthesia In decongestant nasal drops- vasoconstriction of mucosal blood vessels, oedema of nasal mucosa (can - hypertension, tachycardia, reflex bradycardia)

Question 26

Methyldopa

Answer 26

Antihypertensive (when other therapies fail) Competes with NA for uptake 1 Converted to methylnoradrenaline Released in exocytosis of vesicles Activates presynaptic alpha 2 receptors which inhibit NA release, so is a false transmitter Also activate alpha 2 receptors in CNS, so reduced sympathetic drive to CVS, lower bp

Question 27

Guanethidine

Answer 27

Noradrenergic neurone blocker Only used in UK for rapid control of bp in hypertensive emergencies as severe side effects Unknown mechanism, but prevents release of NA

Question 28

Adrenaline

Answer 28

Uses: - resuscitation from cardiac arrest (beta 1) - anaphylactic shock (beta) - CPR- increases heart rate and force (beta 1) - reverses vasodilation (alpha 1) - causes bronchodilation (beta 2) - with local anaesthetics for local vasoconstriction to prolong drug action (alpha 2)

Question 29

Phenylephrine

Answer 29

alpha 1 receptor agonist- to increase bp -Treats nasal congestion (via local vasoconstriction) -Causes mydriasis for eye examination -Can treat acute hypotension in an emergency where other measures fail Side effects: hypertension, tachycardia/reflex bradycardia, reduced perfusion of vital organs

Question 30

Clonidine

Answer 30

alpha 2 receptor agonist- to decrease bp -Treats hypertension -Used to prevent migraine Side effects: dry mouth, depression, sedation, bradycardia, sexual dysfunction

Question 31

Isoprenaline

Answer 31

Mixed beta receptor agonist To treat bradycardia or heart block (beta 1) from overdose of beta blocker Adverse: tachycardia

Question 32

Dobutamine

Answer 32

Mixed beta receptor agonist For support in MI, cardiac surgery or to treat cardiogenic shock (beta 1) Adverse: tachycardia, increase in systolic bp (alpha 1)

Question 33

Dopamine

Answer 33

Mixed beta receptor agonist For cardiogenic shock (beta 1) Adverse: vasoconstriction (alpha 1), tachycardia (beta 1)

Question 34

Levadopa

Answer 34

To treat Parkinson's disease Can cross blood-brain barrier where dopamine can't Is converted to dopamine in the CNS Need to inhibit dopamine production peripherally also with Carbidopa or Benserazide, which cannot cross bbb

Question 35

Phenoxybenzamine, phentolamine

Answer 35

Mixed alpha adrenoreceptor antagonists | -For short term management of hypertensive episodes in Phaeochromocytoma

Question 36

Propanolol

Answer 36

``` Beta blocker (mixed beta adrenoreceptor antagonist) -For angina, arrythmias, MIs, congestive heart failure, hypertension, glaucoma, acute panic attacks ```

Question 37

KD

Answer 37

Dissociation constant | Concentration of drug at which 50% of receptors are occupied

Question 38

Parasymphatholytics | Parasympathomimetics

Answer 38

Parasymphatholytics- antagonise psns, so give SNS effects | Parasympathomimetics- mimic effects of psns

Question 39

Pharmacokinetics

Answer 39

The way the body deals with drugs

Question 40

Pharmacodynamics

Answer 40

The effects of the drug on the body