Antihypertensives I

Question 1

What is mild hypertension?

Answer 1

140-159/90-99

Question 2

What is moderate hypertension?

Answer 2

160-179/100-109

Question 3

What is severe hypertension?

Answer 3

greater or equal to 180/110

Question 4

What are the nonmodifiable risk factors of HPT? (3)

Answer 4

Age
Sex
Family history of early onset of CVD

Question 5

What are the modifiable risk factors of HPT (3)

Answer 5

Dyslipidemia
Diabetes mellitus
Waist circumference: abdominal obesity

Question 6

What is the waist circumference that increases risk?

Answer 6

Male> 102cm
Female>88cm

Question 7

What are the complications of uncontrolled hypertension?

Answer 7

Target organ damage (TOD):
-LV hypertrophy
-Hypertensive retinopathy
-Microalbuminuria or positive urine dipsticks for albuminuria or elevated albumin creatinine ratio
-Elevated Creatinine level 9or eGFR<60ml/min)

Question 8

What clinical conditions are associated with uncontrolled hypertension?

Answer 8

Ischaemic heart disease / MI
* Heart failure
* Stroke / transient ischemic attack(TIA)
* Chronic kidney disease
* Peripheral arterial disease

Question 9

What are the recommended lifestyle modifications in HPT?

Answer 9

Weight reduction
Dash diet (diet approaches to stop hpt)
Lowering dietary sodium
Physical activity
Moderation of alcohol
Complete cessation of smoking

Question 10

What are the factors influencing HPT?

Answer 10

CO X PVR =Bp

Question 11

What are the classes of antihypertensives (5)

Answer 11

• Beta-blocking agents
• Agents acting on renin-angiotensin system
• Vasodilators
• Alpha-adrenoceptor antagonists (doxazosin)
• Calcium-channel blockers
• Agents acting on arterial smooth muscle
• Diuretics
• Centrally acting agents

Question 12

Which drugs act on the arteriolar system? (2)

Answer 12

Hydralazine
Minoxidil

Question 13

What is the MOA of Hydralazine?

Answer 13

Uncertain mechanism of action: relax arteries and arterioles = vasodilation =
↓peripheral resistance = ↓ BP accompanied by reflex tachycardia and ↑
CO

Question 14

Hydralazine interferes with the action of what?

Answer 14

Interferes with the action of inositol triphosphate on Ca2+ release from the sarcoplasmic reticulum

Question 15

What are the indications of Hydralazine (2)

Answer 15

-4th line treatment for hypertension (low doses in combination with b-blocker),
-supplementary tx in chronic cardiac failure
-Indicated for HF in patients of African origin in combination with long-acting
nitrate

Question 16

Adverse effect of Hydralazine

Answer 16

Adverse effect: long-term use can cause immune disorder resembling SLE

Question 17

MOA of Minoxidil

Answer 17

Direct acting vasodilator (by activating K+ channels), accompanied by tachycardia. Increases CO and Potent and long-acting vasodilator

Question 18

Indications of Minoxidil

Answer 18

Last line unresponsive/refractory HPT

Question 19

Can Minoxidil be used as monotherapy? explain

Answer 19

NOT used as
monotherapy, concurrent diuretic and b-blocker often required

Question 20

Adverse effects of Minoxidil (2)

Answer 20

-marked salt and water retention (NOT for heart failure),
prescribed with a loop diuretic,
-hirsutism

Question 21

List selective calcium channel blockers with mainly vascular effects

Answer 21

Amlodipine*
Felodipine
Lecanidipine
Nifedipine*
nimodipine

Question 22

Which drug is a selective CCB with cardiac effects?

Answer 22

Veramipil

Question 23

MOA of CCBs

Answer 23

L-type calcium channels
Block cellular entry of Ca
2+, through calcium channels rather than
preventing its intracellular actions

Question 24

What are the 2 properties of calcium channel antagonists?

Answer 24

Use dependence, the most active calcium channels are more
effectively blocked
* Voltage-dependent blocking, blocking is stronger when the
membrane is depolarised, causing calcium channel opening and
inactivation

Question 25

cardiac actions of CCBs (3)

Answer 25

Cardio-selective: Verapamil (diltiazem intermediate selectivity) * Antiarrhythmic affects (AV block and cardiac slowing) * Negative ionotropic effect (contra-indicated in CCF)

Question 26

Effects of CCBs on vascular smooth muscle

Answer 26

Dihydropyridines – amlodipine * Reflex tachycardia due to vasodilator action * Reduce blood pressure * Can be used in CCF * Coronary vasodilation - use in variant angina (cause by vasospasm) * Other smooth muscles are also relaxed: biliary, urinary, uterine

Question 27

Indications of CCBs

Answer 27

Hypertension: shown beneficial effects on cardiovascular morbidity and mortality.

Question 28

ROA of most CCBs

Answer 28

Mostly given oral with good bioavailability

Question 29

Which CCB is taken IV, and for what indication?

Answer 29

nimodipine for special indication (subarachnoid haemorrhage)

Question 30

Which CCB has a long eliminationn half-life?

Answer 30

Amlodipine (once daily dosing)

Question 31

Which CCBs have short half life?

Answer 31

Nifedipine, verapamil, diltiazem, short half-lives (formulations for once daily dosing available)

Question 32

What are the adverse effects of short-acting dihydropyridines (e.g. Amlodipine)? (2)

Answer 32

Headaches and flushing

Question 33

Adverse effects associated with chronic use of CCBs

Answer 33

Chronic use: ankle swelling (pedal oedema) – due to vasodilation and increased permeability

Question 34

Adverse effects of Verapimil (3)

Answer 34

constipation, heart block, worsening heart failure