1. UNIT 2: ANTIHYPERTENSIVE DRUGS
UNIT INSTRUCTIONAL OUTCOMES:
At the end of this unit, the student should be able to,
Differentiate the types of hypertension
Explain short and long term control of blood pressure
List the classes of drugs used to treat hypertension and their mechanism of action
Recall vital information about the drugs used in hypertension.
List the updates of JNC-8 guidelines in the management of HTN.
Apply pharmacological knowledge gained in the clinical scenario.

2. HYPERTENSION- BASICS JNC 7 Guidelines Blood pressure Classification *
SBP (mm Hg)
DBP (mm Hg)
Normal
<120
<80
Prehypertension
120–139
80–89
Stage 1
140–159
90–99
Stage 2
≥160
≥100
Anand, M.D. Ramachandran, Pharmacology Recall, Second Edition, Wolters Kluwer
* JNC 7 Guidelines;2014

3. Lippincott's Illustrated Reviews: Pharmacology, 4th Edition.

4. Anand, M.D. Ramachandran, Pharmacology Recall, Second Edition, Wolters Kluwer

5. ANTI-HYPERTENSIVES
Lippincott's Illustrated Reviews: Pharmacology, 4th Edition.

6. Journal of Heart;Vol:88;621

7. ANTI HYPERTENSIVES ACTING ON THE RAAS PATHWAY

8. ACE INHIBITORS CONTRAINDICATED IN PREGNANCY
Lippincott's Illustrated Reviews: Pharmacology, 4th Edition.

9. Prodrugs (Except Captopril and Lisinopril) Taste disturbances
ACE INHIBITORS- Key points (Pneumonic CAPTOPRIL)
Cough
Angioedema
Prodrugs (Except Captopril and Lisinopril)
Taste disturbances
Orthostatic hypotension( When combined with diuretics)
Pregnancy (Contraindicated)
Renal artery stenosis (Contraindicated)
Increased K+ (Contraindicated)
Lowers the formation of Angiotensin II

10. Angiotensin Antagonists
Losartan and Valsartan are examples
They block angiotensin at its receptor site, thus inhibiting both
vasoconstriction and aldosterone secreting effects. They do not affect
the bradykinin system.
CONTRAINDICATED IN PREGNANCY
Anand, M.D. Ramachandran, Pharmacology Recall, Second Edition, Wolters Kluwer

11. BETA ADRENERGIC BLOCKERS
Beta-1 blockade in cardio myocyte blocks tachycardia,hypertension and force of contraction of heart.
Beta-2 blockade in lungs causes bronchoconstriction, poor peripheral circulation.
Selective beta-1 blockers are preferred in patients with respiratory troubles as the non selective blockers alters both heart and lungs.
Example for selective beta-1 blockers and non selective blockers are atenelol,metaprolol and propranolol respectively.

12. MOA and ADR of beta blockers
Lippincott's Illustrated Reviews: Pharmacology, 4th Edition.

13. CALCIUM CHANNEL BLOCKERS
Contraindicated in patients with CHF
Anand, M.D. Ramachandran, Pharmacology Recall, Second Edition, Wolters Kluwer

14. CALCIUM CHANNEL BLOCKERS
Anand, M.D. Ramachandran, Pharmacology Recall, Second Edition, Wolters Kluwer

15. DIURETICS
1. Apart from Thiazide diuretics,Loop diuretics and
Spiranolactone also employed in treatment of
hypertension.
2. Indapamide is the only thiazide diuretic which
can be used in HTN patients with
Diabetes Mellitus.
3. Indacrinone can be used in patients with Gout, as it inhibits
reabsorption of uric acid in the nephron( Other loop diuretics
and Thiazides cause Hyperuricemia.
4. All diuretics reduce BP by lowering blood volume which eventually decrease cardiac output.
Anand, M.D. Ramachandran, Pharmacology Recall, Second Edition, Wolters Kluwer

16. ALPHA ADRENERGIC ANTAGONISTS
Anand, M.D. Ramachandran, Pharmacology Recall, Second Edition, Wolters Kluwer

17. CENTRALLY ACTING ANTIHYPERTENSIVES
Both drugs are used to treat mild to moderate hypertension.
Positive coomb’s test and rebound hypertension are the respective ADR of methyl dopa and clonidine respectively.
Guanafacine has same ADR and MOA as that of
clonidine

18. HYPERTENSIVE EMERGENCY
Hypertensive emergency is a rare, but life-threatening situation in which the diastolic blood pressure is either over 150 mm Hg (with systolic
blood pressure greater than 210 mm Hg) in a healthy person or
130 mm Hg in an individual with preexisting complications, such as encephalopathy, cerebral hemorrhage, left ventricular failure, or aortic stenosis.

19. HYPERTENSIVE EMERGENCY
Sodiumnitroprusside,Diazoxide and Labetalol are used in hypertensive emergency.
Sodiumnitroprusside is the doc but cyanide toxicity is
produced during its metabolism which is treated with an
enzyme called Rhodanase
Diazoxide is used in patients with coronary insufficiency.
Labetelol is also used to treat hypertensive emergency
but carries the risk of being nonselective beta blocker.

20. JNC-8 Guidelines
Beta blockers are no longer considered as first line drugs as they increase mortality.
Thiazides diuretics, ACEIs, ARBs and CCBs are first line drugs.
Rest of the drugs are called later line drugs as B.P should be controlled by 1st line drugs/ in combination.
ACEIs and ARBs should not be given to simultaneously to a person.
Irrespective of ethnic background ARBs and ACEIs should be used as 1st choice drugs in CKD patients.
For African patients without CKD, Thiazides and CCBs should be preferred.

21. HYPERTENSION- Summary
Therapeutic goals:
1)Reduce volume overload
2)Reduce sympathetic outflow
3)Block adrenergic receptors of the heart
4)Dilate blood vessels
James Olson, Clinical Pharmacology Made Ridiculously Simple, Second Edition, MedMaster Series