Common drugs Flashcards

Question

Acetylcholinesterase inhibitors: mechanism of action

Answer 1

- ACh is an essential neurotransmitter involved in learning and memory - Alzheimer's and Parkinson's results in ↓ cholinergic activity in the brain - Inhibitors prevent the breakdown of ACh, making it more available for cognitive function

Answer 2

- N,V&D (caused by ↑ cholinergic activity in PNS) - Exacerbation of asthma/COPD Sx - Worsening of tremor in pts with Parkinson's (rivastigmine) Less common, but serious; - Peptic ulcers - Bleeding - Bradycardia - Heart block - Hallucinations - Altered/aggressive behaviour

Answer 3

Use with caution; - Asthma/COPD - People at risk of peptic ulcer development Absolute; - Heart block - Sick sinus syndrome

Answer 4

- NSAIDs and corticosteroids ⇒ ↑ risk of peptic ulcers - Antipsychotics ⇒ ↑ risk of neuroleptic malignant syndrome - Rate-limiting medications ⇒ bradycardia and/or heart block

Answer 5

- Start at 5mg - Titrate up after 2-4w - Reassess for treatment efficacy at 3m - Take before bed - Available as tablet, capsule, or liquid - Explain to pt/caregivers that it is not a cure for dementia

Answer 6

- Start at 1.5mg 12-hrly - Titrate up after 2-4w - Reassess for treatment efficacy at 3m - Available as tablet, capsule, or liquid OR - Available as a patch for pts with swallowing difficulties - Explain to pt/caregivers that it is not a cure for dementia

Answer 7

1. Antidote to paracetamol poisoning | 2. ↓ viscosity of respiratory secretions (mucolytic) for inpatients

Answer 8

- Paracetamol OD overwhelms glutathione protein responsible for 'mopping up' hepatotoxic metabolite, NAPQI - Excess NAPQI is ∴ free to cause liver damage - Acetylcysteine replenishes body's supply of glutathione - Breaks disulphide bonds in mucus ⇒ mucolytic activity

Answer 9

Anaphylactoid rx (if administered IV) - Different to anaphylaxis as there is no IgE involvement - ∴ once rx has settled (by stopping infusion + giving antihistamine ± bronchodilator) it is safe to restart at a lower rate of infusion Bronchospasm (if nebulised) - Manage by giving a bronchodilator (e.g. salbutamol) immediately beforehand

Answer 10

Weight-adjusted dose as IV infusion with 3 components over 21hrs

Answer 11

2.5-5mL of acetylcysteine 10% solution by nebuliser every 6hrs

Answer 12

1. Single dose to ↓ absorption of certain poisons in gut 2. Multiple dose to ↑ elimination of certain poisons Certain poisons include (weakly ionic, hydrophobic); - Benzodiazepines - Methotrexate

Answer 13

- Poisonous molecules are adsorbed onto the surface of the charcoal as they pass through the gut ⇒ ↓ absorption into circulation - If molecules are likely to diffuse back into the gut, multiple doses are used to maintain a steep concentration gradient and eliminate the poison ('gut dialysis')

Answer 14

- Black stools - Vomiting - Aspiration ⇒ pneumonitis, bronchospasm, airway obstruction - Intestinal obstruction

Answer 15

- Pts with ↓ level of consciousness unless airway is protected with endotracheal intubation - Persistent vomiting (caution, ↑ risk of aspiration) - Reduced gut motility (caution, ↑ risk of obstruction)

Answer 16

- Used for patients presenting within 1hr of ingestion of poison - Prescribe on the 'once-only' section of drug chart - 50mg orally (or nasogastric tube if intubated)

Answer 17

- 50mg PO every 4hrs | - Consider prescribing with an antiemetic and a laxative

Answer 18

First-line diagnostic and therapeutic agent for supraventricular tachycardia (SVT)

Answer 19

- Agonist of adenosine receptors on cell surfaces - In the heart ⇒ ↓ frequency of spontaneous depolarisations (automaticity) and ↑ resistance to depolarisation (refractoriness) - ∴ slows sinus rate and conduction velocity and ↑ AVN refractoriness - ↑ refractoriness in AVN breaks re-entry circuit (cause of SVT) ⇒ allows normal depolarisations from SAN to resume control of HR - CARDIOVERSION - Half-life in plasma is <10s - it is rapidly taken up by RBCs

Answer 20

- Bradycardia - Asystole - 'Sinking' feeling in chest + breathlessness + sense of 'impending doom' Only lasts for <10s

Answer 21

Absolute (any pt who will not tolerate its transient bradycardic effects); - Hypotension - Coronary ischaemia - Decompensated HF - Asthma (induces bronchospasm) Relative; - COPD (induces bronchospasm) - Heart transplant recipients

Answer 22

Dypyridamole - Antiplatelet that blocks cellular uptake of adenosine - Prolongs and potentiates adenosine's effects ∴ dose of adenosine should be halved Theophylline/aminophylline - Competitive antagonists ∴ ↓ effect - Require higher dose of adenosine

Answer 23

- IV - Written in the 'once-only' section of drug chart - Start at 6mg IV - If 6mg ineffective ⇒ 12mg IV may be given - If using a central line, halve the dose (i.e. 3mg) - Resuscitation facilities should be on hand - Important that adenosine reaches heart ASAP to avoid peripheral uptake ∴ use a large-bore cannula, sited as proximally as possible (i.e. ACF) - Administer as rapid injection then immediately flush - MUST have a continuous cardiac rhythm strip recorded when administered

Answer 24

1. Cardiac arrest 2. Anaphylaxis 3. Local vasoconstriction (injected directly into tissue to stop bleeding, i.e. mucosal bleeding during endoscopy)

Answer 25

- Potent agonist of α1, α2, β1, and β2 adrenoreceptors - Vasoconstriction of vessels to skin, mucosa, and abdominal viscera (α1) - ↑ HR, force of contraction, and myocardial excitability (β1) - Vasodilation of vessels supplying heart and muscles (β2) - ∴ redirects blood away from non-essential organs and towards the heart - Bronchodilatation and suppression of inflammatory mediator release from mast cells (β2)

Answer 26

- Adrenaline-induced hypertension (following cardiac arrest) - If given to conscious patients ⇒ anxiety, tremor, headache, and palpitations - Angina, MI, arrhythmias

Answer 27

Absolute; - As an anaesthetic-adrenaline preparation in areas supplied by end-artery (⇒ necrosis) Relative; - Caution as a vasoconstrictor in pts with heart disease

Answer 28

Β-blockers - adrenaline may induce widespread vasoconstriction because α1 vasoconstriction is not opposed by β2 vasodilatation

Answer 29

- Administer first, prescribe later (when life-threatening situation) - 1mg IV after THIRD shock, and every 3-5mins thereafter - Pre-filled syringe containing 1:10,000 (1mg in 10mL) solution, then flush

Answer 30

- 1mg IV as soon as IV access is available - Then every 3-5mins thereafter - Pre-filled syringe containing 1:10,000 (1mg in 10mL) solution, then flush

Answer 31

- 500mcg IM, repeated after 5mins if necessary - 0.5mL of 1:1000 (1mg in 1mL) solution - Inject into anterolateral aspect of thigh halfway between knee and hip

Answer 32

- Spironolactone | - Eplerenone

Answer 33

1. Ascites and oedema due to liver cirrhosis 2. Chronic HF 3. Primary hyperaldosteronism

Answer 34

- Aldosterone causes ↑ activity of Na+ channels - ⇒ ↑ reabsorption of sodium + H20 ⇒ ↑BP + ↑K+ excretion - Antagonists inhibit aldosterone by competitively binding to receptors - ⇒ ↑ Na+ + H20 excretion and ↑ K+ retention

Answer 35

- Hyperkalaemia ⇒ muscle weakness, arrhythmias, cardiac arrest - Spironolactone ⇒ gynaecomastia - Liver impairment and jaundice - Stevens-Johnsons syndrome ⇒ bullous skin eruption

Answer 36

Absolute; - Severe renal impairment - Hyperkalaemia - Addison's disease Relative; - Pregnant or lactating women (teratogenic)

Answer 37

Potassium-elevating drugs (e.g. ACE-inhibitors and ARBs) | - Can still use but requires monitoring

Answer 38

- PO OD - Higher doses for ascites vs. HF - 100mg daily (ascites) - 25mg daily (HF) - Taken with food - Tell men about the possibility of growth and tenderness of breast tissue + impotence - Monitor efficacy based on clinical findings (e.g. ↓ ascites or BP) - Monitor safety by checking renal function and serum K+ Spironolactone is used for all indications, eplerenone is only used for HF

Answer 39

- Gaviscon (R) | - Peptic (R)

Answer 40

1. GORD | 2. Dyspepsia

Answer 41

- Compounds of alginates + antacids (e.g. sodium bicarbonate) - Antacids - buffer stomach acid - Alginates - increase viscosity of stomach contents ⇒ ↓ reflux of acid into oesophagus - Drugs form a 'raft' which blocks contents from the gastro-oesophageal junction

Answer 42

- Magnesium salts ⇒ diarrhoea | - Aluminium salts ⇒ constipation

Answer 43

Relative: - Compound alginates should not be given to infants with thickened milk preparations ⇒ excessively viscous stomach contents ⇒ bloating + discomfort - Patients with fluid overload or hyperkalaemia (e.g. renal failure)

Answer 44

- Alginates bind to other drugs to ↓ absorption - Antacids ↓ serum conc. of many drugs - Should take 2hrs after/before taking the following drugs; * ACE-inhibitors * Cephalosporins, ciprofloxacin, tetracyclines * Bisphosphonates * Digoxin * Levothyroxine * PPIs

Answer 45

- Oral suspensions or chewable tablets - Usually PRN - Caution in diabetics as they can have sucrose in

Answer 46

1. Gout 2. Renal stones 3. Hyperuricaemia and tumour lysis syndrome

Answer 47

- Xanthine oxidase inhibitor - Xanthine oxidase metabolises xanthine → uric acid - Inhibitor ↓ plasma uric acid ⇒ ↓ precipitation in joints/kidneys

Answer 48

- Trigger or worsen an acute gout attack (when starting) - Skin rash - Stevens-Johnson syndrome - Toxic epidermal necrolysis - Allopurinol hypersensitivity syndrome

Answer 49

Absolute; - Current acute gout attack - Recurrent skin rash - Signs of severe hypersensitivity to allopurinol Relative; - Renal impairment (lower dose) - Hepatic impairment (lower dose)

Answer 50

- Azathioprine (↑ risk of toxicity, as azathioprine active metabolite is metabolised by xanthine oxidase) - ACE-inhibitors or thiazides (↑ risk of hypersensitivity rx) - Amoxicillin (↑ risk of skin rash)

Answer 51

- PO - Start at low dose (e.g. 100mg OD) - Titrate up according to serum uric acid conc. - Usual maintenance = 200-600mg OD - Prescribe NSAID when first starting for gout to avoid triggering an attack - Encourage good hydration, take after meals - If used for cancer treatment, start before chemotherapy

Answer 52

- Gentamicin - Amikacin - Neomycin

Answer 53

1. Severe sepsis 2. Pylonephritis and complicated UTI 3. Biliary and other intraabdominal sepsis 4. Endocarditis 5. Bacterial skin, eye, or external ear infections (topical)

Answer 54

- Against G-ve aerobic bacteriaa | - Inactive against streptococci and anaerobes, so combine with penicillin/metronidazole when organism is unknown

Answer 55

- Bind irreversibly to bacterial ribosomes ⇒ inhibit protein synthesis - Bactericidal - Enter bacteria via oxygen-dependent transport system (hence ineffective with anaerobes and strep as they don't have these) - Penicillins weaken cell walls, so can enhance aminoglycoside activity by ↑ bacterial intake

Answer 56

- Nephrotoxicity (PC: ↓ urine output + ↑ serum Cr and urea) - reversible - Ototoxicity (PC: hearing loss, tinnitus, vertigo) - irreversible Aminoglycosides accumulate in renal tubular epithelial cells and cochlear and vestibular hair cells ⇒ apoptosis ⇒ death

Answer 57

Relative; - Neonates - Elderly patients - Renal impairment - Myasthenia gravis

Answer 58

- Loop diuretics and vancomycin (⇒ ototoxicity) | - Ciclosporin, Pl chemotherapy, cephalosporins, and vancomycin (⇒ nephrotoxicity)

Answer 59

- Given parenterally (IV for severe infection) - Dose calculated from patient's weight and renal function - Dose is usually 5mg/kg (normal renal function) or 3mg/kg (renal impairment) - Dose interval time is determined by drug level monitoring → subsequent doses only given when plasma conc. has fallen to a safe level (usually 24hr - 48hrs)

Answer 60

Adjusted body weight = [ideal body weight] + 0.4 x ([actual body weight] - [ideal body weight]) - Adipose tissue contains more fat than water - Aminoglycosides are distributed through WATER not fat, and therefore extra weight in obesity complicates dosing - Calculate dose by using adjusted body weight

Answer 61

Diluted and infused slowly to prevent exposure of ear to high conc. bolus

Answer 62

- Mesalazine | - Sulfasalazine

Answer 63

- Ulcerative colitis (mesalazine) | - Rheumatoid arthritis (sulfasalazine)

Answer 64

- Release 5-aminosalicylic acid (5-ASA) - Anti-inflam and immunosuppressive effects - Acts topically on gut (not systemically) - Prepared in a way that active molecules are only released in the colon

Answer 65

- GI upset - Headache - Blood abnormalities (R) - leucopenia, thrombocytopenia - Renal impairment - Oligospermia (reversible) - sulfasalazine - Serious hypersensitivity reaction - sulfasalazine Mesalazine causes fewer SFx than sulfasalazine

Answer 66

Absolute: | - Aspirin hypersensitivity (both salicylates)

Answer 67

- PPIs (increase gastric pH ⇒ tablets are broken down prematurely, i.e. not the colon) - Lactulose (lowers stool pH ⇒ prevents 5-ASA release in colon)

Answer 68

- For mild-moderate rectal/rectosigmoidal UC ⇒ mesalazine enema or suppository - In an acute attack, take once or 12hrly for 4-6w to induce remission - If disease is more proximal or pt doesn't want rectal administration, use oral formulation

Answer 69

Efficacy: - Pt's symptoms for UC - Disease activity scores and measurement of acute phase reactant conc. (CRP, ESR) for RA Safety: - Renal function (for oral mesalazine) - FBC and liver profile (for sulfasalazine)

Answer 70

Tachyarrhythmias (inc. AF, atrial flutter, SVT, VT, and VF)

Answer 71

- Blockade of sodium, calcium, and potassium channels in myocardial cells - Antagonism of α and β adrenergic receptors in myocardial cells - ↓ spontaneous depolarisation (automaticity), slow conduction velocity, and ↑ refractoriness

Answer 72

Acute use: - Hypotension (IV, though probably effect of solvent) Chronic use: - Pneumonitis - Bradycardia - AV block - Hepatitis - Skin photosensitivity - Grey discolouration of skin - Thyroid abnormalities (amIODarone - contains iodine) - Phlebitis (if chronic peripheral administration)

Answer 73

Relative: - Severe hypotension - Heart block - Active thyroid disease

Answer 74

LOADS, but notably... - Digoxin - Diltiazem - Verapamil - Grapefruit juice

Answer 75

- Always requires senior involvement Cardiac arrest: - Given immediately after 3rd shock in ALS algorithm in shockable arrest - 300mg IV, followed by 20mL of 0.9% sodium chloride/5% glucose as a flush - Administer first, prescribe later

Answer 76

- Losartan - Candesartan - Irbesartan

Answer 77

Used when ACE-i are not tolerated (usually because of the cough) Also preferred in black people of African or Caribbean origin

Answer 78

- PO - Lower starting dose in HF - e.g. 12.5mg OD in HF or 50mg OD for other indications - Titrate up over a period of weeks

Answer 79

- Citalopram - Fluoxetine - Sertraline - Escitalopram

Answer 80

1. Moderate-severe depression (or mild if psychological Tx haven't worked) 2. Panic disorder 3. OCD

Answer 81

Inhibit neuronal reuptake of 5-HT ⇒ ↑ availability for neurotransmission

Answer 82

- GI upset - Change in appetite and weight - Hypersensitivity reactions - Hyponatraemia ⇒ confusion + ↓ consciousness - ↑ suicidal thoughts and behaviour - ↓ seizure threshold(?) - Prolong QT interval (citalopram particularly) ⇒ arrhythmias - ↑ risk of bleeding - Serotonin syndrome ⇒ autonomic hyperactivity + altered mental state + neuromuscular excitement - Sudden withdrawal ⇒ GI upset, neurological and influenza-like symptoms, sleep disturbance

Answer 83

Relative: - Epilepsy (↑ risk of SFx) - Peptic ulcer disease (↑ risk of SFx) - Young people (↑ risk of self-harm and suicidality) - Hepatic impairment (↓ dose)

Answer 84

Absolute: - MAOIs - Serotonergic drugs (e.g. tramadol) Relative: - NSAIDs (use gastroprotection due to ↑ risk of bleeding) - Anticoagulants - Other drugs that prolong the QT interval (e.g. antipsychotics)

Answer 85

- PO - Start low and titrate up until good response - Start with 20mg OD

Answer 86

- Amitriptyline | - Lofepramime

Answer 87

- Second line for moderate-severe depression | - Neuropathic pain (unlicensed)

Answer 88

- Inhibit neuronal reuptake of 5-HT and noradrenaline | - Block a wide array of receptors (hence why they have a lot of adverse effects)

Answer 89

Antimuscarinic receptor blockade: - Dry mouth - Constipation - Urinary retention - Blurred vision H1 and α1 receptor blockade: - Sedation - Hypotension Cardiac adverse effects (multiple mechanisms): - Arrhythmias - ECG changes Cerebral adverse effects: - Convulsions - Hallucinations - Mania Dopamine receptor blockade: - Breast changes - Sexual dysfunction - EPSEs (tremor, dyskinesia) Overdose: - Hypotension - Arrhythmias - Convulsions - Coma - Respiratory failure Sudden withdrawal: - GI upset - Neurological and influenza-like symptoms - Sleep disturbance

Answer 90

Relative: - Elderly (↑ risk of SFx) - Epilepsy (↑ risk of SFx) - Cardiovascular disease (↑ risk of SFx) - Prostatic hypertrophy (worsening of urinary retention) - Constipation (worsening symptoms) - Glaucoma (worsening of symptoms)

Answer 91

Absolute: | - MAOIs

Answer 92

- Reserved for use only when other options have failed - Prescribe a small quantity for people at risk of attempting suicide by OD - e.g. amitriptyline 75mg OD

Answer 93

Amitriptyline 10mg at night = starting dose

Answer 94

1. Major depression (where SSRIs are ineffective) | 2. GAD (venlafaxine)

Answer 95

- SNRI - ↑ availability of monoamines for neurotransmission - Weaker antagonist of muscarinic and histamine receptors than TCAs ⇒ ↓ antimuscarinic SFx than TCAs

Answer 96

- Antagonist of inhibitory pre-synaptic α2-adrenoreceptors - ↑ availability of monoamines for neurotransmission - Potent antagonist of histamine receptors (but not muscarinic) ⇒ ↓ antimuscarinic SFx, but DOES cause sedation

Answer 97

- GI upset - Neurological effects - Hyponatraemia (R) - Serotonin syndrome (R) - ↑ suicidality - Prolonged QT interval (venlafaxine) - ↑ risk of ventricular arrhythmias (venlafaxine) - Same withdrawal symptoms as other antidepressants, but venlafaxine causes much worse Sx

Answer 98

Relative: - Elderly (↑ SFx) - Hepatic and renal impairment (↓ dose) - Arrhythmias (venlafaxine)

Answer 99

- PO - Low starting dose and titrate up Venlafaxine: - Start with 37.5mg PO 12-hrly - Maximum 375mg OD Mirtazapine: - Start with 15mg PO OD - Maximum 45mg OD - Take at night to minimise/benefit from sedative effects

Answer 100

- Metoclopramide | - Domperidone

Answer 101

- Prophylaxis and treatment of N&V | - Particularly used with ↓ gut motility associated N&V

Answer 102

- Many stimuli trigger N&V - Various pathways converge on 'vomiting centre' in medulla, which receives input from many systems (e.g. chemoreceptor trigger zone, vestibular system, solitary tract nucleus, etc.) - D2 receptor is the MAIN receptor in the chemoreceptor trigger zone (CTZ) - Receptors detect emetogenic substances in blood - D2-receptor antagonists ∴ are used to counteract nausea from CTZ stimulation - Dopamine also promotes relaxation of the stomach and LOS and inhibits gasproduodenal coordination - D2-receptor antagonists ∴ have prokinetic effect ⇒ ↑ gastric emptying

Answer 103

- Diarrhoea - EPSEs, usually acute dystonic reaction (e.g. oculogyric crisis) (metoclopramide only, domperidone does not cross the BBB) - QT-interval prolongation (domperidone) - Arrhythmias (domperidone)

Answer 104

Absolute: - Neonates - Cardiac conduction abnormalities (domperidone) - Perforation Relative: - Children (at ↑ risk of SFx) - Young adults (at ↑ risk of SFx) - Severe hepatic impairment (domperidone) - Intestinal obstruction - Parkinson's disease (metoclopramide, domperidone is fine as it doesn't cross the BBB)

Answer 105

Absolute: - Dopaminergic agents for Parkinson's disease (will antagonise effects) - Drugs that prolong the QT interval (domperidone) - Drugs that inhibit CYP450 Relative: - Antipsychotics

Common drugs Flashcards

(129 cards)