Lecture 12: Antihypertensives Flashcards
What are the risk factors associated with hypertension?
Major risk for:
- Stroke
- CAD
- Renal disease
CVS death doubles for each 20mmHg systolic rise and 10mmHg diastolic rise
Does treatment of hypertension help?
J shaped curve (yes/no)
10mmHg systolic BP fall: Reduction in morbidity and mortality
What are the hypertension treatments?
Lifestyle changes
- Diet (salt)
- Weight loss
- Exercise
- Reduce alcohol
Drug therapy
- Polypharmacy
Whats the target BP?
Contentious
Aim 130/80
What are the available drugs for hypertension?
A - ACEi/ARB
B - Beta blockers
C - Ca channel blockers
D - Diuretics (thiazide, loop, aldosterone antagonists)
Alpha blockers and others
What ACE/ARBs are recommended for hypertension?
ACEi
Cilazapril (Enalapril, lisinopril)
S/E: Hypotension, cough, angiooedema, hyperkalemia
ARBs
Candesartan (Losartan, valsartan)
S/E: Hypotension, Hyperkalemia
What are the C/I for ACEi and ARB?
- Bilateral renovascular disease (B/c AII maintains perfusion gradient and ACEi/ARB -> Marked hypotension and AKI)
- Pregnancy: Cross placenta and angiotensin has role in renal development
What are the S/E of beta blockers?
- Fatigue
- Bradycardia
- -ive inotrope
- ED
- Asthma exacerbation
- Cold peripheries
What are some thiazide diuretics and where do they act?
Thiazide:
- Hydrochlorothiazide
MoA
- Inhibit Na/Cl in DCT
- Dec. BP with subdiuretic dose
- Vasodilators
Not super clear what its long term action is
What is natriuresis?
Na and thus water loss
WHat is diuresis?
Water loss
What are the thiazide side effects?
Increase glucose
Increased urate
Decreased K, Na, Mg
Diuresis (Mild)
ED
What are some loop diuretics and how do they work?
Frusemide
- Inhibits NKCC
- Potent diuretic BUT little hypertensive effect alone (super effective if with ACEi)
What are the S/E of loop diuretics?
- Dehydration/polyuria
- Dec Na, K, Mg
What are some K sparing diuretics? and MoA?
Spirinolactone (Aldo antagonist)
- Inhibits Na/K exchanger
What are the S/E of spirinolactone?
- Gynaecomastia
- Dehydration
- Hyperkalaemia
Whats the approach to treating hypertension?
Guidelines vary everywhere
But in essence aim to prevent the organ damage and treat the comorbidities i.e vascular disease, HF, renal
Use rods charts
What is young hypertension characterised by?
High renin state
Therefore:
Step One: A or B
Step Two: Add C or D
Step Three: A or B, C+D
Step four (resistant) : Either alpha blocker or spironolactone or other diuretic
What is older person hypertension characterised by?
Low renin state
Therefore:
Step One: C or D
Step Two: Add A or B
Same as young now:
Step Three: A or B, C+D
Step four (resistant) : Either alpha blocker or spironolactone or other diuretic
What are some effective drug combos for hypertension?
Diuretic + ACEi + Vasodilator
i.e
Bendrofluazide + Cilazapril + Felodipine
What are sensible drug prescriptions with comorbidities when it comes to hypertension?
ACEi
- Hypertension + HF
B blocker
- Hypertension + Angina/HF
Diuretic
- Hypertension + HF
Alpha blockers
- Hypertension + Prostatism
What are the lifestyle changes for reducing BP?
- <5g salt per day
- Reduce alcohol/binge drinking
- Diet Veg/fruit/fish/nuts
- BMI
- Aerobic exercise
- Smoking cessation
What can happen with gestational hypertension?
Maternal complications
- Abrupt
- CVA, Organ dysf., coagulopathy
Fetal complications
- IUGR
- Prem
> 140/90
How do you treat maternal hypertension?
AVOID:
- ACEi, ARB
- Atenolol (IUGR)
- Diuretics
Can use:
- Central agents: Methyl dopa
- B blockers: Labetalol
- Ca antagonists: Nifedipine
- Vasodilators: Hydralazine
What are some rarely used anti-hypertensives?
Vasodilators: Hydralazine
Central acting: Methyldopa, Clonidine (dec SNS)
Whats the future of anti-hypertensives?
Polypil - good combinations
