Anti-hypertensive drugs for Nursing Students

Drugs for treating Hypertension. study material for B. Sc Nursing Students Only

2. INTRO
 Hypertension is defined as either a sustained
systolic blood pressure (SBP)of greater than
140 mm Hg or a sustained diastolic blood
pressure of greater than 90 mm of Hg.
 An agent that reduces high blood pressure is
called as an ANTIHYPERTENSIVE.

3. Prehypertension-systolic between 120 to 139 mm/Hg
and diastolic between 80 to 89 mm/Hg.
 Effects of Hypertension
Increases risk of heart disease , heartfailure, kidney
disease, blindness, and stroke.
 Primary Hypertension- No known reason.
Secondary Hypertension-due to some cause such as
kidney disease, abnormalities of adrenal glands
will try nonpharmacological methods first.

4. CLASSIFICATION
DIURETICS
Thiazide Type:
Hydrochlorothiazide,Chlorothalidone,Bendroflume-
thiazide,Trichloromethazide
Potassium Sparing:
Spironolactone,Amiloride,Triamterene
Loop Diuretics: Furosemide,Ethacrynic
Acid,Bumetanide,Torasemide
ACE INHIBITORS
Captopril,enalapril,lisinopril,perindopril,ramipril.
ANGIOTENSIN ANTAGONISTS
Losartan,irbesartan,candesartan

5. CLASSIFICATION (Cont...)
Sympatholytics:
Centrally acting drugs – Clonidine and Methyl dopa.
Ganglionic blockers – Trimethaphan
Adrenergic Neuron Blockers – Resperpine,
Guanithidine.
ß - ADRENERGIC BLOCKERS
Propranolol,metaprolol,atenolol.
+ß ADRENERGIC BLOCKERS
Labetalol,carvedilol.
 - ADRENERGIC BLOCKERS
prazosin.,terazosin,phentolamine

6. CLASSIFICATION (Cont....)
CALCIUM CHANNEL BLOCKERS
Verapamil,diltiazam,nifedipine,felodipine,
amlodipine,lacidipine
VASODILATORS
Hydralazine,minoxidil, sodium
nitroprusside.

7. DIURETICS
It enhance the excretion of Na and Water
resulting in
¯ in plasma volume - ¯ Cardiac Output - ¯ BP
¯Body Na – Relaxation of vascular smooth muscles
- ¯BP
Thiazides are the first line anti hypertensives and
are in expensive, it combined with K+ sparing
diuretics is the best way to avoid hypokalemia.

8. Loop Diuretics – It is a powerful diuretics their
antihypertensive effect is low. It is used only in
hypertension with chronic renal failure or
congestive cardiac failure.
ACE (Angiotensin Converting
Enzyme Inhibitors)
Angiotensin II is a powerful vasoconstrict
aldosterone also raises the BP by increasing the
blood plasma volume.
ACE inhibitor prevent the formation of
angiotensin II and (indirectly Aldosterone) there
is vasodilation and decreased in peripheral
vascular resistance, resulting in BP fall.

9. Vasoconstriction
Increase in BP
Salt & water retention
­ Blood Volume

10. Pharmacokinetics
ACE inhibitors well absorbed
(except captopril and lisinopril)
¯
ACE Inhibitors are excreted through
kidney

11. AE
1.Persistent dry cough due to ­ bradykinin level
is more common in women.
2.Hypotension,head ache,nausea, abdominal pain
3.Hyperkalemia ,proteinuria,neutropenia
4.Dysgeusia (an altered taste sensation) is more
common in captopril.
5.Angioneurotic edema- ACE inhibitors rarely
cause angioedema with swelling in the lips ,nose,
larynx and airway obstruction.
6.skin rashes
7.Teratogenicity

12. USES
1.Hypertension
2.congestive cardiac failure (CCF )
3.myocardial infarction
4.coronary artery disease
5.chronic renal failure
6.Scleroderma renal crisis

13. PRECAUTION AND
CONTRAINDICATION
ACE Inhibitors are contraindicated in
pregnancy.
It should not be combined with K Sparing
diuretics.
At the first sign of angioedema ,ACE should be
stopped.
ACE Inhibitors may enhance the plasma level of
digoxin.

14. Angiotensin II Receptor Blocker
Losartan was the 1
st
orally effective AT 1 receptor
antagonist.
There are 2 sub types of Angiotensin - II
receptors – AT1 & AT2
AT1 receptor are present in vascular and
myocardial tissue, brain, kidney and adrenal
glomerular cells.
Losartan has high affinity for AT1 receptors
when compared to AT2 receptors.
By blocking AT1 receptors Losartan blocks the
effect of angiotensin II.

15. Angiotensin II Receptor Blocker (Cont....)
It relaxes vascular smooth muscles, promotes salt
and water excretions and reduces plasma volumes,
hence the BP also decreased.
Pharmacokinetics
Given Orally
Bioavailability is < than 50 %
All extensively protein bound
Excreted by kidney

16. Angiotensin II Receptor Blocker (Cont....)
Adverse Effects – Hypotension, Hypokalemia,
Angioedema is rare.
Uses:
HT (First line drug of choice)
Cardiac Failure
Renin Antagonist
Aliskiren is a direct renin inhibitor and was
recently introduced. It blocks the effect of renin
and there by reducing the BP.
Dose: 150 – 300 mg once daily.

17. Sympatholytics
These are the drugs acting centrally.
Clonidine is a selective a 2 agonist.
Stimulation of a 2 receptors in the CNS. (in the
vasomotor center and hypothalamus)
Decrease the central sympathetic outflow, blocks
the release of NA from the nerve terminals,
leading to fall in BP.
AE includes drowsiness, dryness of mouth, nose
and eyes. Swelling of parotid gland and pain.
Uses – Mild – Moderate HT, Opioid Withdrawal,
diabetic neuropathy, with anaesthetics.

18. a Methyl Dopa is a pro drug, is metabolized in
the body to a methyl nor ephinephrine, which is
an a 2 agonist. It reduces central symapthetic
outflow leading to a fall in BP.
Uses – Mild - Moderate HT along with Diuretics.
It is safe in HT during pregnancy.
Ganglionic Blockers
This drugs blocks both symathetic and para
sympathetic ganglions resulting in decreased
sympathetic tone and a fall in BP. Trimethaphan
is the only ganglion blocker.
Used for surgeries in IV route.

19. Adrenergic Neuron Blocker
Guanethidine depletes the stores of NA in the
adrenergic neuron and also blocks its release.
It is not used because of its AE.
Reserpine is an alkaloid obtained from ‘Rauwolfia
serpentina’. It destroys vesicles that store NA and
thus depletes the store of these mono amines
and reduces the BP.
Adrenergic Receptor Blockers
a Blockers
1. Non – Selective a Blockers like Phenoxybenzamine
and phentolamine are used in the treatment of HT.

20. Adrenergic Receptor Blockers
a Blockers
2. Selective a 1 Blockers like Prazosin, Terazosin dilates
both aterioles and venules. Peripheral vascular
resistance is decreased leading in fall in BP.
These are mild anti hypertensives. It blocks the b 1
receptors results in decreased myocardial contractility
and cardiac output. Thus they reduce the BP.
Atenolol is the preferred Beta blockers.
b - Blockers

21. Advantage of atenelol is once a day dosing.
Absence of CNS side effects is other advantage
Esmolol is the short acting beta blockers, used in intra
operative and post operative hypertension.
a & b Blockers
Labetalol and Carvedilol block a1 and b receptors.
It is used in IV, in the treatment of Hypertensive
emergencies.

22. Calcium Channel Blockers
They are another important group of anti hypertensives.
They dilate the arterioles resullting in reduced
peripheral vascular resistance.
Nifedipine produce some refelex bradycardia while this
is not seen with Verapamil and Diltiazem as they are
cardiac depressants.
Uses: it is effective particularly in elderly patients.
It may be used in monotherapy in moderate to severe
HT.
It is used in sub lingual route for Hypertensive
emergencies.

23. Vasodilators
It relax the vascular smooth muscles. Thus reducing the
BP. Due to decreased peripheral vascular resistances.
Hydralazine is directly acting arteriolar dilators.
The fall in BP is associated with Tachycardia.
Adverse Effects
Headache, Nausea, Hypotension, Flushings, dizziness and
Palpitation , water retention.
Uses: It is used with beta blockers and diuretics in
moderate – severe HT.

24. Vasodilators (Cont...)
Minoxidil is directly acting arteriolar dilators. In
severe HT not responding to other drugs. It acts by
opening K + channel in the smooth muscles
resulting in reuced BP.
Diazoxide is directly acting potent arteriolar
dilators. It can cause hyperglycemis because it
inhibits the insulin secretion
Sodium Nitroprusside is the rapidly acting
vasodilators. It relaxes both arterioles and
veneules.
AE – Palpitations, Sweating. Nausea and vomiting,
Hypotension.
Uses - drug of choice for HT emergencies. MI

25. NURSING IMPLICATIONS
Risk of fall is evident as vasodilators can cause
postural hypotension. So the patients must be
guarded while getting up.
Palpitations can be due to reflex tachycardia
induced by a vasodilators.
Sodium nitroprusside acts with in a seconds.
BP monitored constantly.
It should be disolved in 2 ml of 5 % dextrose
solution. And than diluted in IV fluids.

26. NURSING
IMPLICATIONS
It is light sensitive, so protected from light
by an opaque wrapping.
If color changes infusion should be
discarded.
Infusion is prolonged blood level of CN and
thiocyanate should be checked.
It should not be prolonged for more than 2
– 3 days.