Pharmacology of Hypertension

Question 1

Main factors affecting BP(3)

Answer 1

Blood volume
Cardiac output
Peripheral Vascular Resistance

Question 2

Main MoA of HTN drugs

Answer 2

Vasodilators
Diuretics
Centrally acting drugs

Question 3

Management of HTN

Answer 3

A/CD rule
DM or <55years

A -ace inhibitors/ angiotensin 2 receptor blocker ARB

Aged >55years/ african descent any age - CCB

A+C
A+C+D  Step 3
ACD +
low dose spironolactone if blood Potassium <4.5mmol/l
a/b-blocker if potassium >4.5mmol/L

Question 4

Vasodilators target sites(7)

Answer 4

Ltype CCB
Potassium channel openers - minoxidil
alpha blockers
Endothelin antagonist
angiontensin receptor blocker
Nitrodilators - GTN
Direct acting vasodilators

Question 5

VAsodilators SE (8)

Answer 5

1. Systemic vasodilation and pressure reduction - baroreceptor - mediated reflex stimulation of the heart >HR and Inotropy
2. Impair baroreceptor function when person stands - othorstatic hypotension and syncope on standing
3. Na and H2O retention >BV + CO
4. GI distress
5. Headaches
6. Non productive cough (> bradykinin)
7. Angioedema
8. Hyperkalaemia (

Question 6

Types of Vasodilators

Answer 6

ACE inhibitors
ATN2R antagonists
CCN
a/b blockers 
Hydralazine
Minoxidil

Question 7

ACE inhibitor MoA

Answer 7

Reduction of activity of ACE ?( angiotensin I prevented from being Angiotensin II)

Question 8

RAAS

Answer 8

Na + Cl re-absorption > water retention
• ADH from posterior pituitary > H2O re absorption in collecting duct
• constriction of blood vessels via AT1 receptors on smooth muscles
• increased sympathetic activity on heart and blood vessels > release of NA and inhibits its re uptake

Question 9

Therapeutic use of ACE inhibitors

Answer 9

HTN (In conj with a diuretic)
HF by systolic dysfunction (In conj with a diuretic)
MI - post. reduce deleterious remodelling

Question 10

ACE inhibitor medications

Answer 10

Ramipril
Lisinopril
Enalapril
Captopril

Question 11

ACEI contraindications

Answer 11

Pregnancy

Bilateral renal artery stenosis

Question 12

ARBs MoA

Answer 12

Block AT1 receptors on blood vessels and heart > coupled to signal pathway that stimulates vascular smooth muscle contraction

Question 13

Therapeutic uses of ARBs

Answer 13

HTN

HF

Question 14

ARB medications

Answer 14

Candesartan 
Irbesartan
Losartan
Telmisartan
Valsartan

Question 15

Uses of diuretics

Answer 15

HTN
CHF
Congenital Heart Defects

Question 16

Classes of diuretics(3)

Answer 16

Thiazides and Thiazide like
Loop Diuretics
Potassium-sparing diuretics

Question 17

Diuretic site of action 
Acetazolamide
Osmotic diuretics - mannitol
Loop diuretics - furosemide
Thiazides -HCZ
Potassium-sparing - Spironolactone

Answer 17

Proximal convoluted tubule
Descending limb of loop of Henle
Ascending limb of loop of Henle
Distal convoluted tubule
Distal convoluted tubule

Question 18

Thiazide

Answer 18

1st line of treatment when CCB are unsuitable due to oedema/heart failure
add on treatment for ACE/ARBs and CCB

Question 19

Thiazide medications

Answer 19

Bendroflumetiazide

Hydrochlorothiazide

Question 20

Thiazide-like medications

Answer 20

Indapamide
Metalozone
Chlorthaliodone

Question 21

Thiazide MoA

Answer 21

Inhibiting Na/Cl co-transporter in DCT. prevents reabsorption of Na

Question 22

Thizide SE

Answer 22

Hyponatraemia//kalaemia
Increased plasma glucose
Impotence

Question 23

Thiazide contraindications

Answer 23

Severe dehydration/hypovolaemia
Pre existing hyponatraemia/kalaemia
long term use of loop diuretiucs - inhuibit exretion of uric acid - worsen gout

Question 24

Thiazide Interactions

Answer 24

reduced by nsaids
drugs that lower potassium - loop duiuretics
monitor electrolytes for hyperkalaemia

Question 25

a blockers used in prostate gland and bladder management

Answer 25

Tamulosin Akfuzosin Silodosine

Question 26

A1-blockers for HTN

Answer 26

Doxazosin Indoramin Prazosin Terazosin

Question 27

A1 blockers SE

Answer 27

``` First dose effect Postural hypotension Tachycardia Headache Nasal congestion Decreased ejaculation ```

Question 28

Uses of Sprinolactone

Answer 28

Treat HTN and HF Oedema low potassium potassium sparing diuretic

Question 29

Spironolactone Pharmocological activity (4)

Answer 29

Mineralocorticoid receptor antagonist -aldosterone Androgen receptor Antagonist - treat hirsutism Glucocorticoid receptor antagonist Progesterone receptor agonist

Question 30

Uses of Minoxidil

Answer 30

``` Vasodilator Antihypertensive Alopecia Rerely indicarted in HTN due to SE Topical 2-5%lotion/gel ```

Question 31

Uses of Hydralazine

Answer 31

Directly acting vasodilator Moderate hypertension when 1st line fails - with beta blockers and diuretics in pregnancy 25-50mg OD

Question 32

When stimulated, the alpha 1 receptors are largely responsible for

Answer 32

Vasoconstriction: Stimulation of alpha 1 receptors helps to constrict the blood vessels. As a result of this, blood pressure will rise. Mydriasis: dilation of the pupil. The contraction of the internal sphincter of the bladder, preventing the flow of urine.

Question 33

alpha 1 receptors respond to

Answer 33

adrenaline and noradrenaline. They are divided into alpha 1 ( vascular smooth muscle) and alpha 2 (presynaptic nerve terminals).

Question 34

Alpha blockers can be subdivided

Answer 34

``` non-selective (1&2) *Phentolamine, Phenoxybenzamine and selective (1 - vascular smooth muscle, bladder neck and prostate gland) *Tamulosin, Alfuzosin, Silodosin ```