HTN Flashcards
1
Q
Aged U55
A
- ACEI/ ARB
- CCB
- Thiazide like diuretic
2
Q
Over 55
A
- CCB
- Thiazide like diuretic
- ACEI/ARB
3
Q
ACEI
MOA
A
- ACEI block the action of ACE, to prevent the conversion of Angiotensin I => Angiotensin II
- Ang II is a vasoconstrictor and stimulates aldosterone secretion
- Blocking its action reduces peripheral vascular resistance (afterload), which lowers blood pressure
- It particularly dilates the efferent glomerular arteriole, which reduces pressure and slows the progression of CKD
- Reducing aldosterone levels promotes Na and water secretion
- Reduces proload, good in HF
4
Q
ACEI
Important adverse effects
A
- Hypotension
- Persistent dry cough- Increased levels of bradykinin (inactivated by ACE)
- Hyperkalaemia
- Worsen renal failure
- Angioedema
5
Q
ACEI
warnings
A
- Renal artery stenosis
- Acute kidney injury
- Pregnant and breastfeeding
- SOME forms of CKD
- Profound hypotension on first dose (particularly when on diuretics), start low and titrate up
6
Q
ACEI
Important interactions
A
- Pottasium elevating drugs
- K supplements
- K sparring diuretics
- NSAID
- Ibuprofen- Kidney damage
7
Q
ACEI
Monitoring
A
- Monitor efficacy- symptoms of breathlessness (HF)
- Check electrolyte and renal function before treatment and 1-2 weeks into treatment
8
Q
Angiotensin receptor blockers (ARB) MOA
Losartan, candesartan, irbesartan
A
- Similar to ACEI but instead of inhibiting Ang I=> Ang II
- Blocks Ang II => AT1 receptor
- Rest is the same
9
Q
ARB
Important adverse effects + Warning
A
- Hypotension (First dose)
- Hyperkalaemia
- Renal failure
- Renal artery stenosis
- AKI
- Pregnant + Breastfeeding
- CKD
- NB- interactions are the same as ACEI + Monitoring
10
Q
CCB MOA
Amlodipine
A
- CCB decrease Ca entry into the vascular and cardiac cells, reducing the intracellular calcium concentration
- This causes relaxation and vasodilation in arterial smooth muscle, lowing arterial pressure
- In heart, CCB reduces myocardial contractility
- Suppress cardiac conduction across the AV node, slowing ventricular rate
- Amlodipine (Dihydropyridines) are relatively selective for the vasculature
11
Q
CCB (Amlodipine)
Important adverse effects + Warnings
A
-
ANKLE SWELLING, Flushing, Headache, Palpitations
- Caused by vasodilation and compensatory tachycardia
- Unstable angina- vasodilation causes reflex increase in contractility and tachycardia, increase O2 demand
- Severe aortic stenosis- provoke collapse
12
Q
Amlodipine
Monitoring
A
- Treatment efficacy can be judged by regular BP monitoring for HTN, enquiry about chest pain for angina and by pulse rate from exam or ECG
- 24 hour tape can be performed to review arrhthmias
13
Q
Thiazide like diuretics
Indapamide
MOA
A
- Thiazides inhibit the Na+/Cl- co-transporter in the distal convoluted tubule of the nephron
- This prevents reabsorption of sodium and its osmotically associated water
- The resulting diuresis causes an initial fall in the extracellular fluid volume
- Over time, compensatory changes (e.g. activation of RAS) tend to reverse this, at least in part
- The long term anti-hypertensive if vasodilation (not understood)
14
Q
Thiazide diuertics
Importand side effects + warning
A
- Preventing sodium ion reabsorption from nephron= Hyponatraemia
- Increases K in urine = may cause hypokalaemia + Cardiac arrhythmias
- Impotence in men
- Hypokalaemia
- Hyponatraemia
- Gout
15
Q
Thiazide diuretics
Interactions + Monitoring
A
- NSAIDs- reduce their effectiveness (not low dose aspirin_
- Loop diuretics= hypokalaemia
- Serum electrolytes before you start and 2-4 weeks after initiation of therapy
- NB- TLD cause hypokalaemia, ACEI cause hyperkalaemia- reduce side effects- also synergistic BP-lowering effect
16
Q
Methyldopa
Indications + MOA
A
- Hypertension
- Methyldopa is metabolised to alpha-methylnoradrenaline, which lowers arterial pressure by stimulation of central inhibitory alpha-adrenergic receptors
- False neurotransmission
- Reduction in plasma renin activity
- Methyldopa has been shown to cause a net reduction in the tissue concentration of serotonin, DA, Adrenaline, NA
17
Q
Methyldopa
Adverse effects
A
- Sedations- usually transient during inital therapy- not to operate heavy machinery
- Headache, asthenia + weakness are all transient
*
18
Q
Methyldopa
Warnings
A
- Contraindicated in
- acute porphyrias (liver disorders in which substances called porphyrins build up in the body, negatively affecting the skin or nervous system)
- Depression
- Paraganglioma
- Phaeochromocytoma (Adrenal gland tumour = to much adrenaline)
- Cautioned in
- Hepatic impairment
- Elderly- STOPP criteria
19
Q
Methyldopa
Interactions
A
- Li- monitor carefully for Li toxicity
- Antihypertensives
- Antagonistic interactions: Sympathomimetics, phenothiazines, TCA and MAOI
- Fe- decrease in the bioavailability of methyldopa when ingested with Fe
20
Q
Methyldopa
Monitoring
A
- BP
- FBC- Before treatment and at intervals during first 6-12 weeks or if unexplained fever
- LFTs- Before treatment and at intervals during first 6-12 weeks or if unexplained fever
21
Q
Minoxidil
Indications
A
- Severe HTN- in addition to diuretic and BB
- Androgenetic alopecia
22
Q
Minoxidil
MOA
A
- Minoxidil lowers systolic and diastolic BP by decreasing vascular resistance by vasodilation
- The smooth musculature of the resistance vessels must be regarded as the site of action for the relaxant effect of minoxidil
- The active metabolite of minoxidil activates the ATP-modulated potassium (K-atp) channel causing K efflux, hyperpolarization and smooth muscle relaxation
23
Q
Minoxidil
Adverse effects
A
- Hair changes
- Fluid retention- oedema
- Pericarditis
- Hypotension
- With TOP application only 1-2% absorbed (may be increased if skin is inflamed
24
Q
Minoxidil
Warnings
A
- Contraindicated in
- Phaeochromocytoma
- Cautioned in
- Acute porphyias, after MI, angina
- Contact with broken, infected, shaved or inflamed skin d
25
Q
Minoxidil
Interactions
A
- Other anti-HTN
- Betanidine (sympathetic-blocking agents) may produce excessive BP reduction/ orthostatic hypotension
26
Q
Minoxidil
Monitor
A
- BP inc L/S BP
- UO- due to fluid retention
- U&E- fluid retention
