Info about the treatment of hypertension

1. Drugs used for the
treatment of
Hypertension
Dr. Pravin Prasad
M.B.B.S., MD Clinical Pharmacology
Lecturer, Lumbini Medical College
1 March, 2019 (17 Falgun 2075), Friday

2. By the end of the class BSN 1st
year students will be able to:
Classify drugs used for the treatment of
hypertension
Explain the mechanism of action, indications
and adverse effects of:
Furosemide and Hydrochlorothiazide
Amlodipine
Captopril
Losartan

3. Hypertension
Most common Cardiovascular Disease
Effects of raised Blood Pressure
 Kidney  renal faiure
 Heart  coronary diseases
 Brain  stroke

4. Hypertension
Types:
 Essential/Primary, and
 Secondary
Diagnosis:
 Repeated, reproducible measurements of
elevated blood pressure

5. Normal Regulation of Blood
Pressure
Blood Pressure = Cardiac Output x Peripheral
Vascular Resistance
Kidney also involved in regulation of BP
Local regulation of BP also seen
Mechanism:
Neural: Baroreflexes via autonomic nerves
Humoral: Renin-Angiotensin-Aldosterone
system

6. Anti-Hypertensive Drugs:
Classification
Diuretics
Hydrochlorthiazide, Furosemide
Sympathoplegics
Clonidine, Labetalol, Prazosin, Propranolol
Direct Vasodilators
Amlodipine, Sodium nitroprusside,
hydralazine
Agents that block production or action of
angiotensin
Enalapril, Losartan, Spironolactone

7. Diuretics: Mechanism of
Action
Furosemide
Hydrochlorothiazide

8. Diuretics: Mechanism of
Action
Inhibits specific transporters in nephrons
Furosemide: Na+-K+-2Cl- cotransport
Hydrochlorothiazide: Na+-Cl- symport
Inhibition leads to:
Decreased Na+ and Cl- absorption
More Na+, Cl- and water passed in urine

9. Diuretics: Mechanism of
Action
Furosemide:
High amount of urine formed (brisk diuresis
occurs)
•Blood volume decreases leading to
decreased in cardiac output
Hydrochlorothiazide:
Small persisting Na+ and volume deficit 
slow development of reduction in PVR
(arterioles)
•Decreased stiffness of wall vessel

10. Diuretics: Uses
Furosemide:
Hypertension complicated by:
•Chronic renal failure, refractory Congestive
Heart Failure
•Resistant to combination regime containing
thiazide
Hydrochlorothiazide:
Mild anti-hypertensive
In combination with other anti-hypertensives
•Potentiates other anti-hypertensives

11. Diuretics: Adverse effects
Hydrochlorothiazide: Hypokalaemia
Furosemide: Acute Saline Depletion
Hyperglycaemia, Hyperlipidaemia
GIT: Nausea/Vomiting, Diarrhoea
CNS: Headache, Giddiness, Weakness,
Paresthesia
Allergic reactions

12. Calcium channel blockers
Amlodipine, Nifedipine, Felodipine,
Nitrendipine, Cilnidipine
Verapamil, Diltiazem: not commonly used
Acts by blocking calcium channels present in
smooth muscles of blood vessels
Leads to vasodilatation and decrease in
blood pressure
Amlodipine: long acting (administered once a
day)

13. Amlodipine: Uses
First line drug for hypertension
Monotherapy
Combination therapy with other anti-
hypertensives
Angina pectoris
Stable angina

14. Amlodipine: adverse effects
Ankle oedema
Palpitation, Flushing
Hypotension
Headache, drowsiness
Nausea, abdominal pain, worsening of gastro-
Esophageal reflux
Skin rashes

15. ACE inhibitors
Includes:
Captopril, Enalapril, Fosinopril, Ramipril
Acts by inhibiting Angiotensin Converting
Enzyme
Hence called ACE inhibitors
Angiotensin-I cannot be converted to
Angiotensin-II (A-II)
Effects of A-II not seen

16. Captopril: Uses
Hypertension
Monotherapy
Combination therapy
Congestive heart failure
Left ventricular dysfunction after myocardial
infarction
Diabetic nephropathy

17. Captopril: Adverse effects
Dry cough, Dysguesia
Hyperkalaemia
Angioedema
Skin rash
Hypotension
Palpitation, tachycardia
Should not be administered in pregnancy

18. Angiotensin Receptor
Blockers
Includes:
Losartan, Valsartan, Telmisartan, Olmesartan
Acts by blocking Angiotensin receptors (AT1)
Effects of A-II blocked
•Vasodilation
•Decreased central and peripheral
sympathetic stimulation
•Decreased aldosterone release

19. Losartan: Uses and Adverse
effects
Uses:
Hypertension
Myocardial infarction
Diabetic nephropathy
Adverse effects:
Hypotension, hyperkalaemia
Angioedema
Headache, dizziness, weakness

20. Conclusion
Blood pressure can be controlled by multiple
ways
Hydrochlorothiazide acts by creating small Na+
deficit
Amlodipine acts by causing relaxation of blood
vessels
Captopril inhibits angiotensin converting
enzymes and decrease availability of
angiotensin-II

21. Any queries?
Next class:
Drugs used in angina and heart failure
Thank you.