Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

PPE Revision > Pharmacology > Flashcards

Pharmacology Flashcards

1
Q

Explain the action of statins

A
  1. Inhibit HMG-CoA reductase so decrease cholesterol production in liver
  2. Increase production of LDL receptors on cell membrane
  3. Increased uptake of LDL cholesterol, further reducing circulating cholesterol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the contraindications of statins?

A

Pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the important ADRs for statins?

A
  • Myopathy (due to high Vd)
  • Increased transaminase levels (liver enzyme)
  • GI disturbances
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the important drug-drug interactions of statins?

A
  • CYP inducers/inhibitors
  • OATP2 inhibitors - prevents excretion into bile
  • May increase effect of warfarin - increase INR
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the secondary benefits of statins?

A
  • Anti-inflammatory
  • Cause plaque reduction
  • Improve endothelial cell function
  • Reduce thrombotic risk
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the action of cholesterol absorption inhibitors and give an example

A

Ezetimibe

Inhibits cholesterol absorption in small intestine. This causes decreased [cholesterol] in liver which upregulates LDL receptors, causing further decrease in circulating cholesterol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the important ADRs for cholesterol absorption inhibitors?

A
  • GI disturbances - diarrhoea, abdominal pain
  • Fatigue
  • Headache
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the action of niacin

A
  • Inhibits lipolysis in adipose tissue
  • Reduces production of free fatty acids - decrease in triglyceride synthesis in liver
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the difference between enteral and paraenteral delivery of drugs?

A

Enteral = drug routes via GI tract

Paraenteral = drug routes not via GI tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe factors affecting systematic entry of a drug

A

Passive factors:

  • Drug lipophilicity
  • Molecular size
  • pH changes

Active factors:

  • Presence of active transport systems
  • Splanchnic blood flow (reduced in HF and shock)
  • Drug destruction by gut
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is bioavailability?

A

Fraction of dose that finds its way into a body compartment

e.g. bioavailability for IV bolus is 100%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Name some factors that affect bioavailability

A
  • Drug formation
  • Age
  • Food (water soluble drugs less likely to be affected by food)
  • Vomiting
  • Malabsorption
  • First pass metabolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is oral bioavailability? How is it calculated?

A

Proportion of orally taken drug (or any other route that is not IV) that enters systemic circulation unchanged

Oral bioavailability = [AUC (oral)/AUC (IV)] x 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is first pass metabolism? What can affect first pass metabolism?

A
  • Any metabolism that occurs before the drug enters systemic circulation
  • Can occur in gut lumen, gut wall, liver
  • Drugs affecting gut motility and pass/active absorption will affect uptake of original drug
  • Liver disease will affect amount of metabolism of drug in liver
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does drug distribution mean?

A

Ability of a drug to enter different compartments of the body (plasma, ECF, ICF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What factors can affect drug distribution?

A
  • Lipophilicity
  • Protein binding - reduced entry into tissues
  • Volume of distribution
  • Tissue protein binding - e.g. bind to muscle
  • Tissue mass/volume and binding site density
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is volume of distribution?

A

A hypothetical measure of how widely a drug is distributed in body tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When is displacement of drugs from proteins important?

A

If there is:

  1. High protein binding
  2. Low Vd
  3. Narrow therapeutic ratio
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is phase I metabolism?

A

Reactive group on parent molecule exposed or added by oxidation, reduction or hydrolysis reactions

Requires CYP450 enzymes and NADPH (high energy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Name the CYP450 inducers?

A
  • P = phenytoin
  • C = carbamazepine
  • B = barbituates
  • R = rifampicin
  • A = alcohol (chronic)
  • S = sulphonylureas & St John’s Wort
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Name the CYP450 inhibitors

A
  • G = Grapefruit juice
  • O = Omeprazole
  • D = Disulfiram
  • E = Erythromycin
  • V = Valproate
  • I = Isoniazid
  • C = Cimetidine & Ciprofloxacin
  • E = Ethanol (acute)
  • S = Sulphonamides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How are drugs excreted in the kidneys?

A
  • Passive glomerular diffusion
  • Organic anion and cation transporters - active tubular secretion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What factors will affect renal excretory elimination?

A
  • Protein binding
  • Tubular secretion - NSAIDs reduce tubular secretion
  • Urinary pH
  • Renal blood flow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does phase II metabolism involve? Give the common molecules used

A

Conjugation of reactive intermediate with polar molecule to form water-soluble complex

Glutathione, sulphate ions, glucoronic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Define clearance with regards to pharmacodynamics.
Volume of plasma that is completely cleared of drug per unit time.
26
How does the heart affect drug elimination?
Reduced organ perfusion (reduced cardiac output or excessive vasodilation)
27
Which drugs exhibit zero order/non-linear kinetics at therapeutic doses?
* High dose aspirin * Phenytoin * Verapamil * Fluoxetine * Alcohol * MDMA
28
What is the difference between first order and zero order kinetics?
First order = elimination determined by concentration of drug Zero order = drug eliminated in set amount per time
29
What is the action of salbutamol?
* Activates B2-adrenoceptors on bronchial smooth muscle * Increases cAMP, increases PKA, sequesters Ca2+ in SR, decreases intracellular calcium * Prevents binding of calcium to myosin light chain * Causes vasodilation
30
What are the ADRs for B2-agonists?
* Tachycardia * Palpitations * Skeletal muscle tremor * Headache * Hypokalaemia
31
What is the mechanism of action of inhaled corticosteroids in asthma?
* Binds to intracellular receptors that travel to nucleus * Up or down-regulates gene transcription * Inhibits pro-inflammatory cytokines from Th2 * Inhibits phospholipase A2 - blocks arachidonic acid and therefore prostaglandins production * Increases B2-adrenoceptor expression * Stabilises mast cell membane - decreases histamine
32
Common ADRs of corticosteroids
* Oropharyngeal candidiasis * Hoarseness * Adrenal suppression * Cushing's syndrome * Osteoporosis
33
Describe the important ADRs for methylxanthines
* Seizures - with overdose * Arrhythmias * Psychomotor agitation * Tachycardia * GI disturbances
34
Describe mechanism of action of muscarinic receptor antagonists used in asthma
* Blocks action of M3-adrenoceptor * Prevents phospholipase C activated release of Ca2+ from SR * Causes bronchodilation
35
What are the important ADRs for muscarinic receptor antagonists?
Dry mouth GI motility disorder (constipation or diarrhoea) Cough Headache Tachycardia
36
Which patients should antimuscarinics be used in with caution?
* Prostatic hyperplasia * Bladder outflow obstruction
37
What are the ADRs for PPIs?
* GI disturbances * Headaches * Risk of gastric atropy - long term use
38
Which patients should omeprazole be avoided in?
* Omeprazole is a CYP450 inhibitor - increases concentrations of other drugs * Those on warfarin or phenytoin
39
What is important therpaeutically regarding PPIs?
* PPI action takes 2-3 days for max efficiency * Not all pumps active all the time * It also takes a few days for restoration of stomach acid, de novo synthesis
40
What are the common ADRs of H2-receptor antagonists?
* GI disturbances * Headache * Dizziness * Fatigue * Gynaecomastia * Rash
41
Which patients should cimetidine be avoided in?
Cimetidine is a CYP450 inhibitor and therefore should be avoided in patients on warfarin or phenytoin
42
What is the mechanism of action of bulk laxatives?
Increase volume of non-absorbable solid residue in gut causing distension and therefore stimulating peristaltic movement
43
What is the mechanism of action of faecal softeners?
Lubricate and soften stool - given as an enema or suppository
44
What is the mechanism of action of osmotic laxatives?
Increase water content of bowel via osmosis
45
What is the mechanism of action of irritant laxatives?
Irritates mucosa causing increase peristalsis and water/electrolyte secretion by mucosa
46
What is the mechanism of action of anti-motility antidiarrhoeals?
* Act on opioid receptors in bowel reducing motility * This increases time for fluid reabsorption * It also increases anal tone and decreases sensory defecation reflex
47
What are the common ADRs for anti-motility antidiarrhoeals?
* Nausea * Flatulence * Headache * Dizziness * Vomiting * Abdominal cramps * Constipation * Drowsiness
48
What is the mechanism of action for D2-receptor antagonists used as anti-sickness medication?
* Blocks D2 receptors found in chemoreceptor trigger zone * This prevents stimulation of vomiting centre in lateral reticular formation of medulla
49
What are the important ADRs for D2-receptor antagonists?
* Diarrhoea, headache, dizziness, hypotension * Domperidone - dry mouth * Metoclopramide - extrapyramidal symptoms
50
What is the mechanism of action of serotonin antagonists?
* Block serotonin receptors in chemoreceptor trigger area * Blocks serotonin receptors of vagal sensory fibres stimulated by serotonin released from enterochromaffin cells
51
What are the common ADRs for serotonin antagonists?
* Headaches * Constipation * Flushing
52
What are the common ADRs for niacin?
* GI disturbances * Flushing, pruritis - prostaglandin mediated * Activation of pepic ulcer * Hepatotoxicity
53
What is the mechanism of action of fibrates?
* PPAR agonist (peroxisome proliferator-activated receptors) * Increases production of lipoprotein lipase * Increases fatty acid uptake and B-oxidation which reduces triglyceride production
54
What are common ADRs for fibrates?
* GI disturbances * Gallstones * Myopathy
55
What are the common ADRs for thiazide diuretics?
* Weakness, impotence, skin rashes * Hypokalaemia * Hyperuricaemia * Impaired glucose tolerance
56
What channel do thiazide diuretics inhibit?
Na/Cl co-transporter in early DCT
57
Which channel do loop diuretics block?
NaK2Cl co-transporter in thick ascending loop of Henle
58
What are the common ADRs for loop diuretics?
* Hyponatraemia * Hypotension * Hypovolaemia * Hypokalaemia * Ototoxicity
59
What channels do aldosterone antagonists act on?
* Na/K-ATPase * ENaC * ROMK
60
What are the important ADRs for aldosterone antagonists?
* Hyperkalaemia * Hyponatraemia * Gynaecomastia * Erectile dysfunction
61
Why should caution be given to prescribing thiazides/loop diuretics and steroids together?
Increased risk of hypokalaemia
62
Why should caution be given to prescribing thiazides/loop diuretics and digoxin together?
Increased risk of hypokalaemia
63
Describe mode of action of biguanides?
* Insulin sensitisers * Increases insulin receptor sensitivity - improves peripheral glucose uptake * Reduces hepatic gluconeogenesis * Slows intestinal absorption of carbohydrates
64
What are the important ADRs for biguanides?
* Loss of appetite * GI disturbances * Lactic acidosis * Vit B12 deficiency
65
Describe the mode of action of sulphonylureas
* Block ATP-sensitive K+ channels in B-cells of pancreas * Results in depolarisation causing Ca2+ influx and insulin exocytosis
66
What are the important drug-drug interactions of sulphonylureas?
* NSAIDs = reduced GFR = prolong action * Warfarin, MAOIs = compete for enzymes * Thiazides, glucocorticoids decrease action
67
Which drugs are contraindicated in pregnancy?
* Sulphonylureas * Statins * Aminoglycosides * Streptomycin * Warfarin * ACE inhibitors * Anti-epileptic medication * Methotrexate
68
What are the important ADRs of sulphonylureas?
* Hypoglycaemia * Weight gain * Hyperinsulinaemia
69
What is the mode of action of glitidines?
Same as sulphonylureas but less potent * Block ATP-sensitive K channels causing increased release of insulin
70
What is the action of thiazolidinediones?
Agonist of PPAR-gamma = regulates transcription of insulin responsive genes causing increased insulin sensitivity in adipose tissue, liver and skeletal muscle
71
What are the common ADRs of ACE inhibitors?
* Dry cough * Angio-oedema * Renal failure * Hyperkalaemia * Hypotension, dizziness, headache
72
What are the ADRs for B-blockers?
* Bronchospasm * Fatigue * Insomnia * Dizziness * Cold extremities * Hypotension * Bradycardia
73
What drug classes are the following drugs? 1. Adenosine 2. Amiodarone 3. Atenolol 4. Amlodipine 5. Amiloride
1. Adenosine - opens ACh sensitive K+ channels causing hyperpolarisation therefore slowing conduction through AV node 2. Amiodarone - Blocks K+ channels in cardiac myocyte, slowing repolarisation and extending action potential 3. Atenolol - B-blocker 4. Amlodipine - Calcium channel blocker 5. Amiloride - Diuretic, ENaC channel blocker
74
What is the role of Levodopa?
L-DOPA is immediate precursor to dopamine It is able to penetrate the blood brain barrier and replenish dopamine lost in neostriatum
75
What is usually given in combination with levodopa?
A peripheral DOPA decarboxylase inhibitor which reduces peripheral breakdown and the amount needed for therpaeutic response
76
Give an example of a dopamine receptor agonist used in the treatment of Parkinson's disease
Ropinirole
77
What are the important ADRs for levodopa, dopamine receptor agonists and MAOIs?
* Nausea and vomiting - action on chemoreceptor trigger zone * Psychiatric side effects - schizophrenia like symptoms * Hypotension * Dyskinesias - long term levodopa use
78
What is the problem of long term use of levodopa?
Levodopa induced dyskinesias Loss of efficacy with long term use - on/off fluctuations
79
What are the drug classes that can be used in Parkinson's disease?
* Levodopa * Dopamine receptor agonists * Monoamine oxidase inhibitors (MAOIs) * Catechol-O-methyl transferase inhbitors * Anticholinergics * Amantadine
80
What is the mode of action of monoamine oxidase inhibitors?
* Inhibit monoamine oxidase B which is responsible for the breakdown of dopamine in the brain
81
What is the mode of action of catechol-O-methyl transferase inhibitors?
* Blocks action of COMT which degrades dopamine
82
What is the mode of action of amandatine with regards to Parkinson's disease treatment?
* Stimulates neuronal dopamine release and inhibition of its reuptake * REMEMBER: Amantadine is also used as an anti-viral - blocks M2 ion channels preventing acidification of endosome and therefore viral disassembly
83
What are the 3 core symptoms fo depression?
1. Low mood 2. Anhedonia (lack of enjoyment) 3. Decreased energy
84
What are the 3 theories surrouding depression?
Depression due to: 1. Deficiency of monoamine neurotransmitters (NA, serotonin, dopamine) 2. Abnormality in the receptors 3. Deficiency in molecular functioning - problem post receptor
85
What is the mode of action of SSRIs? Give an example
* Selective serotonin reuptake inhibitors * Prevent the reuptake of serotonin into pre-synaptic neurone - therefore increasing concentrations in synaptic cleft * Highly selective * Fluoxetine, Citalopram, Paroxetine
86
Why must caution be used when prescribing fluoxetine comparted to other SSRIs?
Displays zero-order kinetics
87
What are the common ADRs for SSRIs and SNRIs?
* Headache * Sweating * Anxiety/agitation * GI disturbances * Sleep disturbances Rare: * Mania * Tremor * Extrapyramidal syndromes
88
What are the important drug-drug interactions for SSRIs?
* MAOIs - fatal serotonergic syndrome
89
What is the mode of action of SNRIs?
* Serotonin/noradrenaline reuptake inhibitors * Inhibit reuptake of serotonin and noradrenaline thus potentiating activity in CNS * Dose dependent - high dose = noradrenaline, low dose = serotonin
90
Was is the therapuetic use of Naloxone and why?
* Reversal of opioid mediated respiratory depression * High affinity, competitive antagonist at opioid receptors
91
What is the therapeutic window? How is it calculated?
* Concentration of drug that is high enough to have a therpeutic effect, but not so high that it has a toxic effect * Therapeutic index = toxic dose in 50% of people/effective dose in 50% of people
92
Define specificity and selectivity with regards to pharmacodynamics
* Specificity - how specific the drug is for binding to the receptor * Selectivity - how selective the drug is for the tissue being targeted
93
Define affinity, efficacy and potency
* Affinity - the ability of a drug to bind to a specific receptor site * Calculated using dissociation constant (Kd) * Efficacy - Maximum response achievable from a drug * Agonist = 100% * Antagonist = 0% * Potency - Defines overall response seen by the receptor once the ligand has bound * Calculated using EC50
94
Describe the difference between on-target and off-target ADRs
* On-target = Exaggerated therapeutic effect of drug, usually by increased dosing * Off-target = interactions with other receptors types secondarily to the one intended for therpeutic effect
95
What is the action of warfarin?
* Block vitamin K's reduction to its active form * Vitamin K required as cofactor in the synthesis of factors II, VII, IX, X
96

PPE Revision (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions