Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Quality Use of Medicines > Mechanism of Action > Flashcards

Mechanism of Action Flashcards

0
Q

Aspirin

A

1) acetylsalicylic acid
2) non-selective NSAIDs
3) Analgesic, anti-inflammatory, antipyretic and antiplatelet actions
4) preventing synthesis of prostaglandins by noncompetitively inhibiting both forms of cyclo-oxygenase (COX), COX-1 and COX-2

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

Paracetamol

A

1) not fully determined
2) analgesic effect may include inhibition of central prostaglandin synthhesis and modulation of inhibitory descending serotonergic pathways
3) anti-pyretic effect is probably due to reduced production of prostaglandins in the hypothalamus
4) negligible anti-inflammatory effects

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

Ibuprofen, Diclofenac, Naproxen

A

1) anti-inflammatory, antipyretic, analgesic
2) nonselective NSAIDs (COX-1 and COX-2)
3) Inhibit synthesis of prostaglandins by inhibiting cyclo-oxygenase (COX)

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

Inhibition of Cyclo-oxygenase 1 (COX-1)

A

1) results in impaired gastric cytoprotection and antiplatelet effets
2) reduction to glomerular filtration rate and renal blood flow

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

Inhibition of cyclo-oxygenase 2 (COX-2)

A

1) results in anti-inflammatory and analgesic action

2) reduction in glomerular filtration rate and renal blood flow

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

Hydrocortisone

A

1) known as cortisol
2) binds to steroid receptors -> reduce inflammatory mediators in the area

2) anti-inflammatory, immunosuppressive and antimitotic activity against cutaneous fibroblasts and epidermal cells
3) vasoconstrictive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Anti-fungal -azoles

Ketoconazole, Clotrimazole, Miconazole

A

1) impair biosynthesis of ergosterol for cytoplasmic membrane, inhibiting fungal growth (fungistatic)

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

Aciclovir

A

1) prevent viral DNA synthesis

2) aciclovir metabolite inhibits and is a substrate for the HPV DNA polymerase -> prevent viral DNA synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Non-sedating antihistamines

Cetirizine, Loratadine, Fexofenadine

A

1) reduce the effects of histamine by binding to the H1 receptor and stabilising it in an inactive form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q 
Sedating antihistamine
(Dexchlorpheniramine = polaramine , Promethazine = phenergen, Doxylamine)
A

1) reduce the effects of histamine by binding to the H1 receptor and stabilising it in the inactive form
2) anti-cholinergic activity
3) Promethazine (Phenergen)- alpha-blocking activity
4) Cyproheptadine (Periactin) - antiserotonin activity

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

Loperimide

A

1) activate opioid receptors in the gut wall, decreasing bowel motility and increasing fluid absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Senna

A

1) direct simulation of nerve endings in colonic mucosa to increase intestinal motility
2) may also cause accumulation of water and electrolytes in the colonic lumen

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

Celecoxib

A

1) anti-inflammatory and analgesic
2) COX-2 selective
3) inhibiting synthesis of prostagladins by inhibiting cyclo-oxygenase (COX)
4) inhibition of COX-2 results in anti-inflammatory and analgesic activity; as well as reduction in glomerular filtration rate and renal blood flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q 
Opioid analgesics
(Morphine, Codeine, Oxycodone)
A

1) mimic endogenous opioids by activating opioid receptors in the central and peripheral nervous systems to produce analgesia, respiratory depression, sedation and constipation
2) reduce transmission of the pain impulse by acting pre- and post-synaptically in the spinal cord, and by modulating the descending inhibitory pathways from the brain
3) cough suppression occurs in the medullary centre of the brain

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

Pure or partial agonists?

Morphine, Oxycodone, Codeine

and, what effect do partial agonists demonstrate in increasing dose?

A 
Mophine = pure agonist
Oxycodone = pure agonist
Codeine = pure agonist

partial agonist = buprenorphine (Norspan)

Partial agonists demonstrate a ceiling response above which an increase in dose does not produce an additional increase in effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Meloxicam

A

1) anti-inflammatory and analgesic
2) selective COX-2 inhibitor
3) inhibits synthesis of prostaglandins by inhibiting cyclo-oxygenase (COX)
4) inhibiting COX-2 reduces inflammatory and provides analgesic effect
5) reduction in glomerular filtration rate and renal blood flow

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

Ranitidine

A

1) H2 antagonists

2) competitively block H2 receptors on parietal cells, reducing gastric acid secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Omeprazole, Esomeprazole

A

1) PPI
2) Irreversibly inactivate the hydrogen/potassium ATPase enzyme system (proton pump), suppressing both stimulated and basal acid secretion.
3) When PPIs are stopped, acid secretion is restored by synthesis of new hydrogen/potassium ATPase

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

Allopurinol

A

1) reduces uric acid production by inhibiting xanthine oxidase, and lowers plasma and urinary urate concentrations.
2) allopurinol metabolised to oxypurinol, which also inhibits xanthine oxidase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Colchicine

A

1) inhibits neutrophil migration, chemotaxis, adhesion and phagocytosis in the inflamed area
2) reduces the inflammatory reaction to urate crystals but has no effect on uric aid production or exretion

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

Methotrexate

A

1) folic acid antagonist
2) inhibits DNA synthesis and cell replication by competitively inhibiting the conversion of folic acid to folinic acid, with cytotoxic, immunosuppressive and anti-inflammatory action

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Prednisolone, Prednisone

A

Corticosteroids regulate gene expression which results in:

1) glucocorticoid effects: gluconeogenesis, proteolysis, lipolysis, suppression of inflammation and immune responses
2) mineralocorticoid effects: hypertension, sodium and water retention, potassium loss
3) prednisone is converted to the phamacologically active prednisolone and vice versa

NB: corticosteroids may have predominantly gluco-corticoid effects (eg dexamethasone), mineralo-corticoid effects (fludrocortisone p444 AHM), or a combination of both (eg ydrocortisone)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Oxymetazoline

A

1) produce vasoconstriction in nasal mucosa

2) decrease nasal blood flow and congestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Phenylepherine, Pseudoephedrine

A

1) act on alpha adrenoreceptors on vascular smooth muscle in the respiratory tract, producing vasoconstriction of dilated nasal vessels, reducing tissue swelling and nasal congestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Amytriptyline

A

1) TCA
2) inhibits reuptake of noradrenaline and serotonin into presynaptic terminals
2) unrelated to the therapeutic effects of the TCAs, they also block cholinergic, histaminergic, alpha1-adrenergic and serotonergic receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Mirtazapine

A

1) tetracyclic antidepressant
2) acts by postsynaptic blockade of serotonin 5HT2 and 5HT3 receptors and presynaptic blockade of central alpha2-adrenergic inhibitory autoreceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Sertraline

A

1) SSRI

2) selectively inhibit the presynaptic reuptake of serotonin (5-hydroxytryptamine, 5-HT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Gliclazide

A

1) increase pancreatic insulin secretion

2) may decrease insulin resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Metformin

A

1) reduce hepatic glucose production

2) increase peripheral utilisation of glucose

29
Q

Insulin

A

1) increase or restore ability to metabolise glucose by enhancing cellular glucose uptake
2) inhibit endogenous glucose output and lipolysis

30
Q

Carbamazepine

A

1) prevents repetitive neuronal discharges by blocking voltage-dependent and use-dependent sodium channels

31
Q

Phenytoin

A

1) prevents repetitive neuronal discharge by blocking voltage-voltage and use-dependent sodium channels

32
Q

Valproate

A

1) prevent repetitive neuronal discharge by blocking voltage-dependent and use-dependent sodium channels

33
Q

Metoclopramide, Domperidone

A

1) stimulates upper GI tract
2) dopamine antagonist activity with antiemetic properties

2) EPSE (usually acute dystonic reactions), due to central dopamine antagonist activity, may occur and are more common in the elderly and in people <20 years.
3) EPSE are rare with domperidone as it does not readily cross BBB
4) prokinetic activity

34
Q

Haloperidol, Risperidone

A

1) mediated by blockade of dopaminergic transmission in various parts of the brain (in particular the limbic system)

Evidence suggest:

2) all effective antipsychotics block D2 receptors
3) differential blockade of other dopamine receptors (eg D1) may influence therapeutic and adverse effects
4) antagonism of other receptors may influence antipsychotic activity

35
Q

Lithium carbonate

A

1) unknown
2) inhibition of dopamine release
3) enhancement of serotonin release and decreased formation of intracellular second messengers
4) little or no psychotropic effect in normal individuals

36
Q

Ethinyloestradiol (oestrogen)
Levonorgestrel (progestogen)
Norethisterone (progestogen)

A

1) all COCs contain an oestrogen and progestogen
2) inhibit ovulation
3) reduce receptivity of endometrium to implantation
4) thicken cervical mucus to form a barrier to sperm

37
Q

Alendronate

A

1) decrease bone resorption by inhibiting osteoclasts

38
Q

Thyroxine

A

1) known as T4 or levothyroxine
2) thyroid replacement therapy
3) best ingested in a fasting state, food impairs absorption

39
Q

Levodopa + benserazide/carbidopa

A

1) levodopa is converted to dopamine in the brain and peripheral tissues, and replenishes depleted striatal dopamine
2) benserazide/carbidopa is a peripheral dopa decarboxylase inhibitor which reduces peripheral dopamine production and also reduce adverse effects (eg nausea, vomiting, hypotension)

40
Q

Diazepam

A

1) benzodiazepines potentiate the inhibitory effects of GABA throughout the CNS, resulting in anxiolytic, sedative, hypnotic, muscle relaxant and antiepileptic effects

41
Q

Digoxin

A

1) slows heart rate and reduces AV nodal conduction by an increase in vagal tone and a reduction in sympathetic activity
2) increase the force of myocardial contraction by increasing the release and availability of stored intracellular calcium

42
Q

Atenolol, Metroprolol

Antihypertensive effect
CNS effect
Anti-anginal effect
Anti-arrhythmic

A

1) beta-blocker
2) competitively block beta receptors in heart, peripheral vasculature, bronchi, pancreas, uterus, kidney, brain and liver
3) antihypertensive effect: due to reduction in cardiac output without reflex increase in peripheral vascular resistance
4) CNS effect: and reduced renin secretion may also contribute
5) anti-anginal effect: due to reduction in left ventricular work and oxygen use, resulting from decrease in heart rate and contractility
6) anti-arrhythmic properties: antisympathetic effect -> depress sinus node function and atrioventricular node conduction, and prolong atrial refractory periods

Atenolol - beta 1
Metroprolol - beta 1

beta1-selectivity: higher affinity for beta1 receptors in the heart, with less effect on beta2 receptors in bronchi and peripheral vasculature. beta1-selectivity diminishes with higher doses

43
Q

Clopidogrel

A

1) thienopyridines
2) active metabolite irreversibly binds to platelet P2Y12 receptor and inhibits platelet aggregation for the life of the platelet

44
Q

Heparin

A

1) inactivate clotting factors IIa (thrombin) and Xa by binding to antithrombin III

45
Q

Warfarin

A

1) Vit K antagonist
2) inhibits synthesis of vitamin K-dependent clotting factors (II, VII, IX, X) and the anti-thrombotic factors protein C and protein S

46
Q

Dabigatran

A

1) direct thrombin inhibitors
2) reversibly inhibit both free and fibrin- bound thrombin, preventing conversion of fibrinogen to fibrin, preventing thrombus formation
3) inhibition of thrombin-induced platelet aggregation

47
Q

Frusemide

A

1) loop diuretics (potent diuretics)
2) inhibit reabsorption of sodium and chloride in the ascending limb of the loop of Henle (this site accounts for retention of approx. 20% of filtered sodium)

48
Q

Spironolactone

A

1) aldosterone antagonist (weak diuretic)
2) inhibit sodium absorption in the distal tubule by antagonising aldosterone -> increasing sodium and water excretion and reducing potassium excretion
3) aldosterone may contribute to the pathophysiology of heart failure; by reducing aldosterone activity, aldosterone antagonists improve outcome

49
Q

Hydrochlorothiazide

A

1) moderately potent diuretics
2) inhibit reabsorption of sodium and chloride in the proximal (diluting) segment of the distal convoluted tubule and produce a corresponding increase in potassium excretion
3) used in recommended low doses for hypertension, thiazides lower BP mostly by a vasodilator effect

50
Q

Captopril, Perindopril

A

1) ACE-I = angiotensin converting enzyme inhibitor
2) block conversion of angiotensin I to angiotensin II
3) inhibit breakdown of bradykinin

4) reduces the effect of angiotensin II-induced vasoconstriction, sodium retention and aldosterone release
5) reduce the effect of angiotensin on sympathetic nervous activity as a growth factor

51
Q

Atorvastatin, Simvastatin

A

1) lipid-lowering
2) competitively inhibit 3-hydroxy-3methylgglutaryl coenzyme A (HMG-CoA) reductase (a rate limiting enzyme in cholesterol synthesis)
3) increase hepatic cholesterol uptake from blood
4) reduce concentrations of total cholesterol, LDL and triglyceride (modest) and produce a small increase in HDL concentration

52
Q

Irbersartan

A

1) known as angiotensin II antagonists, angiotensin receptor antagonist or angiotensin receptor blocker
2) competitively block binding of angiotensin II to type I angiotensin (AT1) receptors
3) reduce angiotensin-induced vasoconstriction, sodium reabsorption and aldosterone release

53
Q

Amlodipine

A

1) dihydropyridines calcium channel blocker
2) block inward current of calcium into cells in vascular smooth muscle, myocardium and cardiac conducting system via L-type calcium channels
3) act on coronary arteriolar smooth muscle to reduce vascular resistance and myocardial oxygen requirements, relieving angina symptoms

4) dihydropyridines - act mainly on arteriolar smooth muscle to reduce peripheral vascular resistance and BP. Have minimal effect on myocardial cells

54
Q

Verapamil

A

1) non-dihydropyridine calcium channel blocker
2) block inward current of calcium into cells in vascular smooth muscle, myocardium and cardiac conducting system via L-type calcium channels
3) act on coronary arteriolar smooth muscle to reduce vascular resistance and myocardial oxygen requirements, relieving angina symptoms

4) non-dihydropyridines - act on cardiac and arteriolar smooth muscle. they reduce cardiac contractility, heart rate and conduction, with verapamil having the greater effect. (Diltiazem has a greater effect on arteriolar smooth muscle than verapamil)

55
Q

Glyceryl trinitrate

A

1) provide exogenous source of nitric oxide, which mediates vasodilator effects
2) predominantly venodilators
3) reduce venous return and preload to the heart
3) reducing myocardial oxygen requirement

56
Q

NRT (nicotine replacement therapy)

A

1) reduce the severity of tobacco withdrawal symptoms and increases the likelihood of smoking cessation
2) eMIMS

57
Q

Amoxycillin

Amoxycillin/ clavulanic acid

A

1) bactericidal - mainly gram+ and anaerobes, some gram- (more with clavulanic acid)
2) interfere with bacterial cell wall peptidoglycan synthesis by binding to penicillin-binding proteins -> leads to cell lysis and death
3) clavulanic acid -> bacteria that secretes beta-lactamase

4) amoxycillin - moderate spectrum
4) amoxycillin/clavulanic acid - broad spectrum

58
Q

Flucloxacillin

A

1) bactericidal - narrow spectrum gram+
2) interfere with bacterial cell wall peptidoglycan synthesis by binding to penicillin-binding proteins -> leads to cell lysis and death

59
Q

Phenoxymethylpenicillin

A

1) bactericidal - narrow spectrum mainly gram+ and anaerobes, 2 gram-
2) interfere with bacterial cell wall peptidoglycan synthesis by binding to penicillin-binding proteins -> leads to cell lysis and death

60
Q

Cephalexin

A

1) cephalosporin family
2) bactericidal - some gram-, gram+ and anaerobes
3) interfere with bacterial cell wall peptidoglycan synthesis by binding to penicillin-binding proteins -> leads to cell lysis and death
4) moderate spectrum for cephalexin

61
Q

Clarithromycin

A

1) macrolides (broad spectrum)
2) bacteriostatic - some gram-, gram+, most anaerobes, and miscellaneous ones (like chlamydia and legionella)
3) inhibit bacterial protein synthesis by binding to the 50S ribosomal subunit
4) also have immunomodulatory and anti-inflammatory effect

62
Q

Metronidazole

A

1) nitroimidazole family
2) bactericidal - gram+, gram- anaerobic, protozoal infections
3) metabolised to active metabolites that are thought to interfere with DNA synthesis

63
Q

Ciprofloxacin

A

1) quinolone family
2) bactericidal - mainly gram-
3) inhibit bacterial DNA synthesis by blocking DNA gyrase and topiosomerase IV

NB: there is increasing worldwide resistance to quinolones. Judicious use may extend their clinical life

64
Q

Doxycycline

A

1) tetracycline family
2) bacteriostatic - some gram+, gram-, protozoa
3) inhibit bacterial protein synthesis by reversibly binding to 30S subunit of the ribosome
4) effect of tetracyclines in acne vulgaris also involves mechanisms other than their antimicrobial activity

65
Q

Trimethoprim

Trimethoprim/ sulfamethoxazole

A

1) other antibacterials
2) bacteriostatic - gram-, and some gram+, no data for anaerobes
3) competitively inhibits bacterial folate production essential for bacterial growth

66
Q

Fluconazole

A

1) azole family
2) fungistatic - candidiasis, alternative choice for cryptococcal
3) impair the synthesis of ergosterol in fungal cell membranes leading to their breakdown
4) cell leakage and death occur by lytic activity of the host defense system

67
Q

Salbutamol, Terbutaline

Salmeterol

A

1) salbutamol/terbutaline - SABA (short-acting beta2-agonist)
2) salmeterol - LABA (long-acting beta2-agonist)
3) relax bronchial smooth muscle by stimulating beta2-adrenoceptors

68
Q

Fluticasone

A

1) reduce airway inflammation and bronchial hyper-reactivity

69
Q

Tiotropium

A

1) anticholinergic

2) promote bronchodilation by inhibiting cholinergic bronchomotor tone

Quality Use of Medicines (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions