Hypertension Flashcards

Question

ACE inhibitors: examples + indications

Answer 1

* ramipril, lisinopril, perindopril 1. hypertension 2. chronic heart failure 3. ischaemic heart disease 4. diabetic nephropathy + CKD w/ proteinuria

Answer 2

* ACE inhibitors **block** action of the ACE * prevent conversion of ang I to **ang II** * ang II = _vasoconstrictor_ + stimulates aldosterone secretion * blocking its action reduces peripheral vascular resistance -\> **lowers BP** * particularly **dilates efferent glomerular arteriole** -\> reduces intraglomerular pressure + slows progression of CKD * reducing aldosterone level **promotes sodium + water excretion** * this can help to reduce venous return -\> beneficial in HF

Answer 3

* **hypotension** (particularly after firt dose) * **persistent dry cough** (due to inc levels of bradykinin) * **hyperkalaemia** (bc lower aldosterone -\> K⁺ retention) * cause or worsen **renal failure** too * rare idiosyncratic effects = angioedema, other anaphylactoid rxns Tend not to use ACEi in renal artery stenosis, AKI, pregnant women, breastfeeding,

Answer 4

* **Angiotensin receptor blockers (ARBs)** * eg. losartan, candesartan * same indications * similar MOA, instead of inhibiting Ang I -\> II conversion, they **block action of Ang II on AT₁ receptor** * unlike ACEi, less likely to cause cough and angioedema

Answer 5

examples: **amlodipine, nifedipine, diltiazem, verapamil** 1. amolidipine + nifedipine used for first/second line tx for **hypertension** 2. all ca-ch blockers used to control symptoms of **stable angina** 3. diltiazem and verapamil used to control cardiac rate in ppl w/ **supraventricular arrhythmias** incl supraventricular tachycaria, atrial flutter and atrial fibrilation

Answer 6

* they decrease Ca²⁺ entry into vascular and cardiac cells * reducing intracellular calcium conc * causes **relaxation + vasodilation in arterial sm muscle** -\> lowering arterial pressure * in heart, calcium channel blockers **reduce myocardial contractility** * they **suppress cardiac conduction** across AV node -\> slowing ventricular rate * reduced cardiac rate, contractility + afterload -\> **reduce myocardial oxygen demand** * preventing angina * CaCh blockers: * **dihydropryidines** (amlodipine, nifedipine) - selective for vasculature * **non-dihydropyridines** (verapamil) - more cardioselective

Answer 7

**amlodipine + nifedipine:** * ankle swelling, flushing, headache, palpitations **verapamil:** * constipation, bradycardia, heart block, cardiac failure diltiazem has mixed effects so can cause both sets of adverse effects

Answer 8

eg. bendroflumethiazide, indapamide, chlortalidone 1. **alternative first-line tx for hypertension** where a _ca-ch blocker_ would otherwise be used but is either unsuitable or there are features of heart failure 2. thiazides also an **add-on treatment for hypertension** in pts whose BP not adequately controlled by a calcium-channel blocker plus an ACEi/ARB

Answer 9

* thiazide (bendro) vs thiazide-like (indapamide, chlortalidone) * differ chemically but similar effects + uses * **thiazides inhibit the Na⁺/Cl^- co-transporter in distal convoluted tubule of nephron** * prevents reabsorption of sodium + its osmotically associated water * resulting diuresis causes initial fall in ECV * over time, compensatory changes (eg. activation of RAAS) tend to reverse this, at least in part * long-term antihypertensive effect prob mediated by **vasodilatation** (incompletely understood)

Answer 10

* **hyponatraemia** (not usually problematic) * **hypokalaemia** * increased delivery of sodium to distal tubule, exchanged for potassium, increases urinary potassium losses * -\> **cardiac arrhythmias** * **impotence** in men

Answer 11

eg. doxazosin, tamsulosin, alfuzosin * first line med option to improve symptoms in **benign prostatic hyperplasia**, when lifestyle changes insufficient. 5a-reductase inhibitors may be added in selected cases. surgical treatment also an option, particularly if there is evidence of urinary tract damage (eg. hydronephrosis) * as an add-on tx in **resistant hypertension**, when other medicine (Ca-ch blockers, ACEi, thiazides) are insufficient

Answer 12

* most drugs in this class highly selective for a1-adrenoreceptor * a1-adrenoreceptors found mainly in sm muscle - blood vessels + urinary tract (bladder neck + prostate in particular) * stimulation induces contraction; blockade induces relaxation * a1-blockers therefore cause * **vasodilatation -\> fall in BP** * **and reduced resistance to bladder outflow**

Answer 13

* postural hypotension * dizziness * syncope particularly prominent after first dose (rather like with ACEi and ARBs)

Answer 14

eg. bisoprolol, atenolol, propranolol, metoprolol 1. ischaemic heart disease 2. chronic heart failure 3. atrial fibrilation 4. supraventricular tachycardia 5. hypertension

Answer 15

* b**1**-adrenoreceptors located mainly in heart * b**2**-adrenoreceptors found mostly in sm muscle of blood vessels + airways * via the b1-receptor, **B-blockers reduce force of contraction + conduction speed of heart** * this relieves myocardial ischaemia by reducing cardiac work + oxygen demand -\> increasing myocardial perfusion * improve prognosis in heart failure by protecting the heart from effects of chronic sympathetic stimulation * they slow ventricular rate in AF mainly by **prolonging refractory period of AV node** * SVT often involves a self-perpetuating circuit that takes in the AV node; B-blockers may break this and restore sinus rhythm * in **HT**, B-blockers lower BP through variety of means, one of which is by **_reducing renin secretion_** from kidney since this is mediated by b**1**-receptors

Answer 16

* fatigue * cold extremeties * headache * GI disturbance (nausea) * can cause sleep disturbance + nightmares * may cause impotence in men remember to avoid in pts w/ asthma, choose B1-receptor selective blocker (eg. all prev mentioned but propranolol which is non-selective) in COPD

Hypertension Flashcards

(40 cards)