This document discusses various classes of drugs used to treat hypertension, including their mechanisms and side effects. It describes how diuretics, ACE inhibitors, calcium channel blockers, alpha/beta blockers, and other classes work to lower blood pressure by relaxing blood vessels, reducing fluid retention, or inhibiting hormone systems like renin-angiotensin-aldosterone. Common side effects across drug classes include low blood pressure, dizziness, fatigue, and electrolyte imbalances. Regular monitoring is important when taking antihypertensive medications.

2. Antihypertensives
are a class of drugs that are used
to treat hypertension (high blood
pressure).
Antihypertensive therapy seeks to
prevent the complications of high
blood pressure, such as stroke
and myocardial infarction.

3. Classes
Diuretics
Adrenergic receptor antagonists
Benzodiazepines
Calcium channel blockers
Renin Inhibitors
ACE inhibitors
Angiotensin II receptor antagonists
Aldosterone receptor antagonists
Vasodilators
α2 agonists
Endothelin receptor blockers

4. • Hydrochlorothiazide, a popular
thiazide diuretic
• Loop diuretics:
–Furosemide
• Thiazide diuretics:
• Thiazide-like diuretics:
• Potassium-sparing diuretics:
–spironolactone
Diuretics

5. Action
Act on kidney
Relax blood vessel
walls
Remove more
sodium and water
from water
Lower blood
pressure

6. • Thiazide diuretics are recommended as the
first line of treatment for high blood pressure.
They are usually recommended as one of at
least two medicines to control high blood
pressure.
• Loop diuretics are prescribed for people who
also have heart failure, kidney problems, or
swelling in their legs (edema)

7. • Furosemide, like other
loop diuretics, acts by
inhibiting NKCC2, the
luminal Na-K-2Cl
symporter in the thick
ascending limb of
the loop of Henle.
• By inhibiting the
transporter, the loop
diuretics reduce the
reabsorption of NaCl and
also diminish the lumen-
positive potential that
derives from K+ recycling

8. • Spironolactone is used primarily to treat heart
failure, edematous conditions such as nephrotic
syndrome or ascites in patients with liver
disease, essential hypertension, hypokalemia.
• spironolactone is only a weak diuretic because it primarily
targets the distal nephron (collecting tubule), where only
small amounts of sodium are reabsorbed, but it can be
combined with other diuretics to increase efficacy.
• The antihypertensive effect of spironolactone may exceed
that of complex combined regimens of other
antihypertensives since it targets the primary cause of the
elevated blood pressure.

9. Adrenergic receptor antagonists
• Beta blockers
– atenolol
– Metoprolol
• Alpha blockers
• Mixed Alpha + Beta blockers:
– labetalol

10. Beta
Blockers
Inhibits the
effect of nor
epinephrine and
epinephrine
And lessens the
feedback
mechanism
G protein receptor
kinase inhibits
receptor activity
Increase in cyclic
Adenosine
monophosphate
Improves
contractions
Decrease heart
rate, Calcium
entry into failing
myocytes

11. Labetalol combines both
selective, competitive, alpha-1-adrenergic blocking
and nonselective, competitive, beta-adrenergic
blocking activity in a single substance.
Stimulation of
beta receptors
within
myocardium
Stimulation of
alpha receptors
within vascular
smooth muscles
Decrease in
systemic arterial
blood pressure
and systemic
vascular resistance
Without a reduction in
heart rate, cardiac
output or stroke
volume.

12. Benzodiazepines
• They work as an agonist of the GABA-a receptors in the
brain, thus slowing down neurotransmission and dilating blood
vessels.
• benzodiazepines inhibit the re-uptake of a nucleoside chemical
called Adenosine, which serves as an inhibitory chemical
mentioned above. It also serves as a coronary
vasodilator, allowing the cardiac muscle to relax and dilating
cardiac arteries.

13. Calcium channel
blockers
• block the entry of
calcium into muscle
cells in artery walls.
Peripheral arterial
dilatation
Stimulation of
renin and
formation of
angiotensin
Decrease systemic
vascular resistance
Decrease in
blood pressure
Amlodipine
Nifedipine
Diltiazem

14. Diltiazem
• Diltiazem is a potent vasodilator, increasing blood flow and
variably decreasing the heart rate via strong depression of A-V node
conduction.
• Because of its negative inotropic effect, diltiazem causes a
modest decrease in heart muscle contractility and reduces
myocardium oxygen consumption.
• Its negative chronotropic effect results in a modest
lowering of heart rate, due to slowing of the sinoatrial node. It
results in reduced myocardium oxygen consumption.
• Because of its negative dromotropic effect, conduction
through the AV (atrioventricular) node is slowed, which
increases the time needed for each beat. This results in reduced
myocardium oxygen consumption

15. Renin Inhibitors
Renin inhibitors bind to
the active site of renin and
inhibit the binding of renin to
angiotensinogen.
renin inhibitors prevent
the formation of Ang I and
Ang II A reduction in Ang II
levels or blockade of
angiotensin receptors
suppress the feedback
loop
increased plasma renin
concentrations (PRC)
and plasma renin
activity(PRA)

16. ACE
Inhibitors
Blocks the conversion of
angiotensin I to angiotensin II
Lower arteriolar
resistance
Increase venous
capacity
Normally Angiotensin II causes
vasoconstriction and hence
hypertension.
Decrease
cardiac output
Increase excretion of
sodium in the urine
Stimulates adrenal gland to
release aldosterone which
causes sodium retention and
hence increase in blood
pressure.
Stimulates post. Pituitary to
release vasopressin which
also increases water
retention
With ACE inhibitors, the
production of angiotensin II
is decreased, leading to
decreased blood pressure.
Captopril
Enalapril
Ramipril

17. Angiotensin
II receptor
antagonists
These substances are AT1-receptor
antagonists; that is, they block the
activation of angiotensin II AT1 receptors.
vasodilatation.
reduces secretion of
vasopressin.
reduces production
and secretion
of aldosterone.
The combined effect
reduces blood
pressure.
olmesart
an
telmisart

18. Vasodilators
• Vasodilators act directly on the smooth muscle of
arteries to relax their walls so blood can move more
easily through them; only used in hypertensive
emergencies.
Vasodilatation works to decrease
TPR and blood pressure through
relaxation of smooth muscle cells
in the tunica media layer of
large arteries and smaller
arterioles.
TPR: total peripheral resistance

19. α2 agonists
Stimulate alpha
receptors in the brain
Open peripheral
arteries
For treating
hypertension, these
drugs are usually
administered in
combination with a
diuretic.
Adverse effects of this class
of drugs include
sedation, drying of the nasal
mucosa and rebound
hypertension.

20. Endothelin receptor blockers
By blocking this
interaction, bosentan
decreases pulmonary
vascular resistance.
Under normal
conditions, endothelin-1
binding of ET-A or ET-B
receptors
causes constriction of the
pulmonary blood vessels.
Bosentan is a competitive
antagonist of endothelin-1 at
the endothelin-A (ET-A) and
endothelin-B (ET-B) receptors.

21. Side Effects
of Diuretics
Potassium-sparing diuretics retain the potassium that other
diuretics cause the body to excrete. Common side effects of
these diuretics include nausea, headache and stomach upset.
The most
common side
effect of loop
diuretics, such
as Lasix, is
hypokalemia, or
low potassium.
Other side effects
include dry
mouth, weakness
, diarrhea and
headache.
difficulty
urinating, gout, a
nd hives are
severe side
effects and
should be
addressed
immediately.
Thiazide diuretics
can cause
orthostatic
hypotension.

22. Side Effects
of ACE
Inhibitors
Common side effects of ACE
inhibitors are
diarrhea, headache and joint
pain.
Fever and chills, trouble
breathing or jaundice requires
immediate attention.

23. May include
fatigue, dizziness
and weakness.
Side Effects
of Beta
Blockers

24. Regular check-Up