Lecture 4 - Hypertensive Drugs Flashcards
What is the equation for Mean Arterial Pressure?
MAP = Cardiac output x TPR
MAP = Diastolic BP + 1/3(Systolic BP - Disastolic BP)
Systolic BP - Diastolic BP = Pulse pressure
What regulates blood pressure?
Autonomic sympathetics
Renin Angiotensin Aldosterone System (RAAS)
What are some autocoids (locally acting compounds) produced by vascular endothelium mon vascular smoooth muscle?
Bradykinin
Nitric oxide
How are radius and resistance of a blood vessel related?
Smaller the radius the larger the resistance
With vasoconstriction of vascular smooth muscle what must happen to BP to keep supplying blood at the same rate in systemic circulation?
Inc Peripheral resistance would mean BP needs to increase to meet the systemic demands
How does hyperinsulinaemia and hyperglycaemia lead to hypertension?
Leads to endothelial dysfunction
Increased ROS which leads to less NO signalling
NO is a potent vasodilator
What are the long term effects of hypertension on the body?
Hypertrophy of vasculature
Decreased compliance of vessels
End organ damage (renal, peripheral vascular disease, aneurysm, vascular dementia and retinal disease)
Hypertensive heart disease (Left Vntricular hypertrophy)
Why does hypertension and disease related to hypertension more prevalent in men than women before menopause?
Oestrogen has a protective affect on the vasculature but once menopause has been reached risk becomes similar
What is the definition of hypertension?
An elevated blood pressure that treated will do more good than harm
140/90 mmHg
Normal range: 90/60 - 120/80 mmHg
How do we increase awareness and increase the amount of people we can diagnose with hypertension?
Screening those at risk
Inc public awareness of risk factors
Appropriate lifestyle changes
Regular monitoring and refinement of meds once initiated
Reliable measurements based on clinical guidelines!!
How do we clinically diagnose hypertension?
Sitting relaxed and arm supported
Measure both arms and use higher reading arm, if theres more than a 15mmHg
When measuring someone’s BP what systolic and diastolic measurements should we need emergency treatment if they have clinical signs?
SBP > 180
DBP > 120
What is the target BP for someone younger than 80 with T2DM?
<140/90 mmHg
What is the target BP for someone older than 80 with T2DM?
<150/90 mmHg
What is the target BP for someone with the highest Urine albumin to creatinine ratio of 70mg/mmol or more?
<130<80mmHg
What are the 3 stages of Hypertension?
Stage 1 hypertension. 140/90 - 159/99 mmHg
Stage 2 hyper tension 160/100 - 180/120mmHg
Stage 3 severe hypertension 180/120mmHg >
What do we consider prehypertension?
120/80 - 140/90 mmHg
What interventions should be put in place for those who are classified as having pre hypertension?
Regular exercise
Modify to o have healthy balanced diet
Reduce stress
Reduce alcohoool
Smoking cessation
Reduce caffeine
Reduce dietary sodium
What are the main categories of primary hypertensive therapeutic agents?
ACEi
ARBs (Angiotensin Receptor Blockers)
Calcium Channel Blockers
Diuretics (thiazide and thiazide like)
Other agents
What is ACE?
Where is it found?
What is its functon?
Angiotensin converting enzyme located on the capillary endothelial cells mainly int he lungs
It converts Angiotensin 1 to angiotensin 2
What receptors does Angiotensin 2 act on?
AT1 mainly
AT2
What is the effect of angiotensin II acting on AT1 receptors?
Inc aldosterone production which increases reabsorption of ions and water in DCT
Inc ADH production
Vasoconstrictor
What is the mechanism of action ACEi in acting as an anti-hypertensive?
Limits conversion of angiotensin I -> Angiotensin II
Less angiotensin II =
-vasodilation (less vasoconstriction)
-reduced aldosterone release (more Na+ and H20 lost)
-reduced cell growth and proliferation
What is also a substrate for ACE?
What can be a side effect of ACEi?
Bradykinin
Dry cough due to bradykinin build up
