M3 L2: Antihypertensives

Question 1

what is bp

Answer 1

• force circulating blood exerts on the arterial walls
• heart pumps out blood into diff tissues thru arteries
• circulating blood carries; nutrients and O2 to tissues, waste and CO2 back to the heart

Question 2

normal arterial bp

Answer 2

120/80
systolic: heart contraction (1st #)
diastolic: heart relaxation (2nd #)

Question 3

factors controlling BP

Answer 3

1. blood volume
   - increased volume, increased BP
   - decreased volume, increased BP
2. peripheral resistance
   - vasoconstriction (VC) to increased pressure to increased bp
   - vasodilation to decreased pressure to decreased bp
3. sympathetic nervous sys activity:
   - increased SNS to increased noradrenaline to vasoconstriction to increased BP
   - decreased SNS to decreased noradrenaline to vasodilation to decreased bp
   Renin-angiostensin-aldosterone sys (RAAS)…

Question 4

RAAS sys

Answer 4

1. bp falls
2. angiotensinogen
   renin
3. angiotensin `
   angiotensin-converting enzyme
4. angiotensin 2
5. aldosterone -> salt retention
   OR
6. ADH
   which results in bp rising

Question 5

what is hypertension

Answer 5

PB > 140/90

mild: 140-159/90-99
moderate: 160-179/100-109
severe: greater of more than 180/greater or more than 110

Must do the blood pressure 3x while patient is at rest to be sure and diagnose
When a patient is stressed - put them in a quiet room with dim light to let them relax

Question 6

types of hypertension

Answer 6

primary hypertension:
- no identifiable cause
- most common
secondary hypertension:
- caused by underlying disease (renal disorders, endocrine disorders, pregnancy, etc)
- treat the problem: for example treat Cushing syndrome (that adds steroids, if you fix this blood pressure will reduce)

Question 7

hypertension risk factors

Answer 7

non controllable: genetics, age, etc
controllable: physical activity, smoking, food, etc

Question 8

diagnosis of hypertension

Answer 8

• usually asymptomatic
• based on measuring BP
• manifestation of complications

Hypertension may be the first manifestation you see, could lead to something much worse like heart failure

Question 9

complications of hypertension

Answer 9

heart:
- left ventricular hypertrophy
- heart failure
- CAD (coronary artery disease)
- PAD (peripheral artery disease)

brain:
- TIA
- cerebral strokes
- encephalopathy

eyes:
- hypertensive retinopathy
- papilledema
- loss of vision

kidneys:
- renovascular disease
- renal failure

Question 10

control of hypertension

Answer 10

• life long
• target values:
  hypertension alone: less then 140/90
  hypertension + DM (diabetes): less than 130/80
• decrease incidence of complications
• increase compliance!

Question 11

hypertension non compliance

Answer 11

causes:
- dietary ex: high salt
- meds: cost, side effects, long term therapy
improvement: behavioural changes

Question 12

treatments for hypertension (3)

Answer 12

non-pharmacological measures
pharmacotherapy
treatment of complications

Question 13

hypertension non-pharmacological measures

Answer 13

modification of lifestyle
- dietary management
- change habits

Question 14

pharmacotherapy: antihypertensive drugs

Answer 14

diuretics (specially thiazide diuretics), sympatholytics, calcium channel blockers (CCB), drugs acting on RAAS, vasodilators

Question 15

sympatholytics

Answer 15

• decreased SNS activity
  include:
• α blockers
• β blockers
• α and β blockers (ex: labetalol - pregnancy)
• adrenergic neuron blockers (ex: reserpine, guanethidine, methyldopa - pregnancy)
• centrally acting drugs (clonidine)

Question 16

α blockers
1. mechanism
2. other uses
3. side effects
4. example

Answer 16

1. block α receptors -> decrease constricting effect of norepinephrine on smooth muscle cells of blood vessels -> vasodilation
2. prostatic enlargement, raynaud’s disease
3. orthostatic hypotension -> syncope
4. prazosin

Question 17

β blockers
1. mechanism
2. side effects
3. types

Answer 17

widely used
cardioprotective
1. block β receptors and decrease SNS effect on cardiovascular sys (all decrease: HR, myocardial contractility, cardiac output, myocardial o2 demand, renin secretion)
2.
- bronchospasm, -> asthma
- bradycardia -> heart block
- heart failure
- impotence
3.
- nonselective β antagonist ex: propranolol
- selective β1 antagonist (cardioselective) ex: atenolol (THIS ONE IS GOOD)

Side effects: BAD FISH
B: bradycardia/bronchospasm
A: av blocks/arrythmias
D: depression/dizziness
F: fatigue
I: impotence
S: signs of hypoglycemia
H: hypotension

Avoid In elderly because of the adverse effects

Question 18

drugs acting on RAAS

Answer 18

1. angiotensin converting enzyme inhibitors (ACEI)
2. angiotensin receptor blockers (ARB)

Question 19

ACE Inhibitors
1. mechanism
2. pros
3. cons
4. example

Answer 19

1. angiotensin-converting enzyme
2. safe in asthma, no impotence, useful in diabetes
3. dry cough, hyperkalemia, teratogenic
4. captopril, enalapril, ramipril

Question 20

angiotensin receptor blockers
1. mechanism
2. examples

Answer 20

1. block the action of angiotensin 2 at the AT-1 receptors
   - sim effect as ACEI
   - lower incidence of cough
2. losartan, valsartan

Question 21

vasodilators

Answer 21

dilate blood vessels

classification:
- arterial dilators ex: hydralazine
- venous dilators ex: organic nitrates
- combined ex: sodium nitroprusside

Question 22

choice of antihypertensive

Answer 22

• encourage monotherapy
• effective w minimal side effects
• more suitable for patient’s condition

recommended:
- old age, heart failure - diuretics
- DM - ACEI or ARB
- CAD - selective β1 blockers
- Pregnancy - methyldopa or labetalol
- prostatic enlargement - α blockers

avoid:
- β blockers in asthma and advanced HF
- ACEI/ARB during pregnancy

Question 23

initial monotherapy of hypertension

Answer 23

thiazide diuretics
β blockers
ACEI/ARB
Calcium channel blockers (CCB)

can use acronym “ABCD”
A - angiotensin converting enzyme inhibitors, angiotensin receptor blockers
B - β blockers
C - calcium channel blockers
D - diuretics - thiazides