This document discusses drugs used to treat hypertension. It classifies antihypertensive drugs into diuretics, sympathoplegics, direct vasodilators, and agents that block the renin-angiotensin-aldosterone system. Specific drugs discussed include furosemide, hydrochlorothiazide, amlodipine, captopril, and losartan. Their mechanisms of action, uses, and potential adverse effects are explained. The document emphasizes that blood pressure can be controlled through multiple pathways and drug classes.

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.