Hypertension Flashcards
Name 4 examples of ACE-inhibitors.
-Prils! Captopril Enalapril Lisinopril Ramipril
MOA ACE-inhibitors (5)
Inhibit angiotensin converting enzyme (prod by lungs), causing:
• Inhibit ANGIOTENSIN 2 - vasoconstrictor and growth promoter by stim adrenals
• increase BRADYKININ: vasodilator (release NO and prostacyclin)
• reduce ALDOSTERONE secretion: reduced Na and H20 retention
• reduce activity of sympathetic nervous system: A2 usually promote release noradrenaline, inhibit NA reuptake
• also improve ß receptor density, variation HR, baroreceptor functions, autonomic function
Indications ACE-I (3)
- Hypertension!
- Heart failure (LV dysfunction, slow progress) first line!
- Renal dysfunction ( esp diabetics ) .
Contraindications ACE-I (3)
Pregnancy
Renovascular disease
Aortic stenosis
Adverse effects ACE-I (6)
- First dose hypotension (so give at night before bed)
- Dry cough (bradykinin)
- Functional renal failure (in bilat renal a stenosis, foetus with oligohydramnios)
- Hyperkalemia (reduced aldosterone)
- Rare: urticaria, angioedema (esp afro-caribbean)
- Dizzy, headache, diarrhea, muscle cramps
Drug interactions ACE-I (3)
- K sparing diuretics, K supplements (hyperk )
- NSAIDs (hypotension and hyperk )
- Loop and thiazide diuretics indicated! (diuretics increase renin which would normally decrease efficacy but ACE-I interrupt loop to make diuretics more effective-beneficial!)
Calcium channel blockers 3 types or classes and example of each
- Phenilakylamines: verapamil! Rate-limiting.
- Benzothiazepines: diltiazem
- dihydropyridines: nifedipine! (Short acting 1st gen), felodipine (long-acting 2nd gen), amlodipine! (3rd gen), nimlodipine
MOA CCBS (4)
Dihydropyridines: block L-type calcium channels in vascular cells (control contractile state of actomyosin), therefore reduce calcium influx → vasodilatation reduce peripheral vascular BP, lower arterial BP
Rate limiting or phenylalkalines: block channels in vascular AND heart - reduce cardiac contractility, reduced myocardial oxygen consumption, decreased HR and as above. High doses may affect AVN conduction.
Which population does CCBS work best for for HT??
Black patients -more effective than ACE-I or ARBS
Indications CCBs (4)
- Treat and prophylax angina (esp dihydropyridines;benzothiazepines)
- And HT (long acting dihydropyridines eg felodipine , amlodipine;and nifedipine)
- Supraventricular arrhythmia (verapamil and diltiazem )
- Raynaud syndrome (nifedipine)
Contraindications calcium channel blockers (3)
- Cardiogenic shock
- Dihydropyridines: advanced aortic stenosis
- Verapamil and diltiazem: severe heart failure (negative inotropic action) ß blockers (R AV block and impaired cardiac output), severe bradycardia
Adverse effects dihydropyridines (4)
(CCBS: nifedipine, amlodipine, felodipine)
• Headache and flushing (vasodilation)!
• Ankle swelling (increased pedal capillary pressure)!
• reflex tachycardia (activation baroreceptors and SNS )
• hypotension, rash, dizzy, possible risk GIT bleed elderly, exacerbate HF
Adverse effects benzothiazepines and phenylalkylamines (3)
(Ccbs: diltiazem and verapamil)
• heart block (negative inotrope)
• constipation (relax smooth muscle)
• hypotension, rash, bradycardia, CCF
Drug interactions CCBS
Dihydropyridines and B blockers favourable in moderate-severe HT uncomplicated by HF
IV verapamil and beta blockers: potentially fatal in treatment tachy-arrythmias
3 types diuretics used in HT
Thiazides (preferred - most relevant)
Loop diuretics
K-sparing diuretics
Thiazides diuretics MOA (2)
- Act on cortical nephron to inhibit reabsorption Na and Cl in early distal convoluted tubule resulting in natriuresis
- activate atp-regulated potassium channels in resistance arterioles, causing hyperpolarisation. This inhibits calcium influx into vascular smooth muscle cells with consequent VASODILATION and reduced peripheral vascular resistance.
Examples thiazides diuretics (2)
Hydrochlorothiazide
Bendroflumethiazide
(-Thiazide)
Indications thiazides diuretics in HT
Stage 1 where CCBS contraindicated
Severe hypertension in combination
Indications thiazides - like diuretics in HT
Same as thiazides, but preferred
Examples thiazide-like diuretics (2)
Chlortalidone
Indapamide
Adverse effects thiazides diuretics (3)
- impotence (increased plasma renin)
- electrolyte changes: hypo-everything. Hypo Na, K, mg
- metabolic changes: hyper- everything. Hyper uricemia, glycemia, calcemia, cholesterolemia
ß blockers - 2 types and examples
(-olol)
• Cardio-selective (B1 receptors): atenolol! Bisoprolol, metoprolol
• Non-selective (B 1 and 2): Propanolol!
Vasodilating: carvedilol
MOA B blockers (6)
Decrease heart rate! Decrease systolic BP! Decrease cardiac contractile activity Decrease myocardial oxygen demand Reduce renin secretion Reduce sympathetic Acutely increase peripheral resistance!
Indications ß blockers (6)
- Angina
- Post MI
- Arrhythmia
- HT 4th line and with associated IHD
- Stabilise pts with dissecting aortic aneurysms (IV)
- Thyrotoxicosis, glaucoma, anxiety
- CHRONIC Hf from LV systolic dysfunction first line! With an ace-i: bisoprolol, metoprolol, carvedilol
