Drugs list Flashcards
1
Q
What is the action and some features of acetazolamide?
A
- Carbonic anhydrase inhibitor , non-competitive.
- Inhibits bicarbonate reabsorption in the proximal tubule, therefore increasing renal bicarbonate loss.
- Increases bicarbonate loss so assists rectification of alkalosis at altitude, allowing ventilatory drive to increase to mitigate hypoxia. Increases rate of acclimatisation.
- Gives a head start to acclimatisation to high altitudes since renal excretion of bicarbonate is required for central chemoreceptor adaptation and this process is usually slow
- Altitude sickness
- Side-effects: mild diuresis, dizziness, tingling
2
Q
What is the action and some features of adrenaline that are relevant to APP?
A
- Strong beta-adrenoreceptor agonist (also activates alpha receptors)
- Acts as a bronchodilator through actions at beta-2 adrenoreceptors - useful in asthma
- Anaphylaxis - strong vasoconstrictor, counters the systemic vasodilation to prevent vasodilatory shock
- Need to consider that administration of adrenaline can result in hypokalaemia
- Causes a transient hyperkalemia followed by hypokalemia:
- This is due to the fact that it is a non-selective adrenergic agonist
- The hyperkalemia is due to it acting on alpha receptors
- The hypokalemia is due to it acting on beta-2 receptors
- Causes a transient hyperkalemia followed by hypokalemia:
3
Q
What is the action and some features of aminophylline?
A
- Part of the xanthine/methylxanthine class of drugs.
- Phosphodiesterase III inhibitor , inhibits cAMP breakdown so amplifies effect of β-adrenoreceptor stimulation.
- Used to treat asthma, acutely. Used in hospitalsintravenously when asthma is so severe salbutamol cannot reach the airways.
- Requires close monitoring of heart as has systemic sympathetic side effects eg. increased heart rate, output, blood pressure, arrhythmia, chest pain etc etc
4
Q
What is the action and some features of amlodipine?
A
- Dihydropyridine VGCC inhibitor.
- On spec, for hypertension.
- Passive systemic vasodilation.
- Appears to cause selective vasodilation of afferent arteriole in kidney, preserving GFR as not to increase renin release.
5
Q
What is the action and some features of aspirin that are relevant to APP?
A
-
Antipyretic action
- Through inhibition of prostaglandin synthesis, is able to reduce body temperature
- Inhibition of the enzyme cyclooxygenase (COX), preventing the synthesis of inflammatory prostaglandins (including PGE2), which will lead to raised body temperature set points in the anterior hypothalamus
- PGE2 acts on E2 receptors in the anterior hypothalamus to raise the set point of body temperature
- Recent studies on the mechanism of action have revealed effects independent of COX inhibition as well
6
Q
What is the action and some features of atenolol?
A
- Selective β1-adrenergic antagonist; cardioselective.
- Used in hypertension. This is primarily as they reduce RAAS activation - reduce peripheral vasoconstriction and fluid retention.
- Also reduce sympathetic drive to reduce CO and thus MAP.
- Used in heart failure. This is to reduce sympathetic drive to reduce myocardial oxygen consumption.
- Also reduce RAAS activation - reduce peripheral vasoconstriction, reduce afterload.
7
Q
What is the action and some features of atracurium?
A
*Neuromuscular blocking agent used as an adjuvant for general anaesthesia.
*It is a non-depolarising skeletal muscle relaxant (competitively binds w/ cholinergic receptor)
8
Q
What is the action and some features of atropine?
A
- Muscarinic antagonist.
- On spec - adjuvant in anaesthesia to reduce glandular secretions eg. saliva.
- Also can be given during anaesthesia to treat bradycardia.
9
Q
What is the action and some features of beclomethasone?
A
- Steroid - synthetic glucocorticoid.
- Acts at nuclear glucocorticoid receptors, reduces phospholipase A2 synthesis.
- Reduces synthesis of lipid mediators of inflammation - prostaglandins, leukotrienes, platelet activating factor.
- On spec, inhaled as chronic treatment for asthma (oral if severe).
- Side-effects - increased risk of infections (esp respiratory infections if inhaled), hyperglycaemia, sodium/fluid retention, hypertension.
10
Q
What is the action and some features of bendroflumethiazide?
A
- Thiazide diuretic.
- Treatment of hypertension. Increases fluid loss at kidney by inhibiting NCC in distal tubule, to treat volume hypertension.
- Treatment of congestive heart failure - relief of oedema by fluid loss and vasodilation. However, reducing circulating volume activates SNS and RAAS, increasing myocardial O2 demand and worsening problem. Now rarely used.
- Tends to lose effectiveness over time.
- Side-effects: hypokalcaemia, metabolic alkalosis, hypercalcaemia, hyperuricaemia.
11
Q
What is the action and some features of bupivacaine?
A
- VGNaC inhibitor. Used as a local anaesthetic.
- On spec as adjuvant for general anaesthesia.
- They can be used for post-operative pain relief
12
Q
What is the action and some features of dexamethasone?
A
- Steroid - synthetic glucocorticoid.
- Acts at nuclear glucocorticoid receptors, reduces phospholipase A2 synthesis.
- Reduces synthesis of lipid mediators of inflammation - prostaglandins, leukotrienes, platelet activating factor.
- Reduces inflammation and oedema.
- Reduces oedema in high-altidude pulmonary oedema and high-altitude cerebral oedema.
- Exact method by which this is beneficial in HACE is not known
- (Prostaglandins sensitise C-fibre pain neurons, so reduces inflammatory pain. Analgesic)
- Side-effects:
- Immune depression, susceptibility to infection
- Hypertension - action at mineralocorticoid receptor, sodium/fluid retention
- Bone resorption, diabetes, peptic ulcers, impaired skin healing
13
Q
What is the action and some features of digoxin?
A
- Cardiac glycoside, inhibits Na+/K+-ATPase.
- Used as a cardiac inotrope (positive) in treatment of heart failure. Said to increase contractility without O2 demand but trials have had mixed results.
- Result in increased intracellular sodium and thus increased extrusion in exchange for calcium. This leads to increased contractility.
- Clinically, most commonly used in treatment of atrial fibrillation.
- Very narrow therapeutic window. Can cause arrhythmia, loss of appetite, nausea.
- Contraindictions - kidney failure, acute MCI, vfib.
14
Q
What is the action and some features of doxazosin?
A
- α1-adrenergic antagonist.
- Used to cause systemic vasodilation in hypertension.
- However, can inhibit baroreceptor reflex by preventing constriction of lower vessels - orthostatic hypotension, fainting.
15
Q
What is the action and some features of furosemide?
A
- Loop diuretic. Inhibits NKCC.
- Treat hypertension but thiazide diuretics are more commonly used.
- May be used when tolerance is mounted against thiazides so a stronger diuresis is needed.
- Treatment of congestive heart failure - relief of oedema by fluid loss and vasodilation.
- However, reducing circulating volume activates SNS and RAAS, increasing myocardial O2 demand and worsening problem.
- Electrolyte disturbances also increase risk of MCI.
- Now rarely used, apart from one-off injection for acute pulmonary oedema after MCI.
- Also, ototoxic in high doses.
- Side-effects: hypokalcaemia, metabolic alkalosis, hypocalcaemia, hyperuricaemia.
