Anti-Hypertensive drugs

1. Antihypertensive DrugsAntihypertensive Drugs

2. HYPERTENSIONHYPERTENSION is the strongest modi-is the strongest modi-
fiable risk factor for coronary heart disease.fiable risk factor for coronary heart disease.
It is also responsible for considerableIt is also responsible for considerable
(potentially preventable) disability from(potentially preventable) disability from
stroke, heart and renal failure.stroke, heart and renal failure.
Despite this,Despite this, usually, hypertension continuesusually, hypertension continues
to be underdiagnosed and undertreatedto be underdiagnosed and undertreated..
Many clinical investigations show theMany clinical investigations show the
relationship between meanrelationship between mean blood pressureblood pressure
(BP) and the risk of coronary heart disease(BP) and the risk of coronary heart disease
(CHD) and stroke (insultus cerebri).(CHD) and stroke (insultus cerebri).

3. Most patients with persistent arterial disease
have ESSENTIAL HYPERTENSIONESSENTIAL HYPERTENSION.
But hypertension is occasionally secondary
to some distinct disease:
•Coarctation of aorta
•Renal artery stenosis
•Parenchymal or obstructive renal disease
•Cushing’s syndrome
•Pheochromocytoma, etc.

4. 90%90%
5%5% 5%5%
EssentialEssential
hypertensionhypertension
Renal
Renal
Others
Others

5. Sponsored
Medical Lecture Notes – All Subjects
USMLE Exam (America) – Practice

7. There is changes in perceived normsThere is changes in perceived norms
recently target values for blood pressure.​​recently target values for blood pressure.​​
Norm now takenNorm now taken 135/85 mm Hg135/85 mm Hg..
For patients over 60 years old todayFor patients over 60 years old today
accepted by cardiologists targetedaccepted by cardiologists targeted
values for blood pressure are​ ​values for blood pressure are​ ​
140/90 mm Hg​​140/90 mm Hg​​ , and in people, and in people
over 80 years oldover 80 years old theythey
areare 150/90 mm Hg​​150/90 mm Hg​​ ..

8. Cushing’s syndromeCushing’s syndrome
is a side effect ofis a side effect of
glucocorticosteroidsglucocorticosteroids
(hydrocortisone,(hydrocortisone,
betamethasone, etc.)betamethasone, etc.)
The main symptom isThe main symptom is
arterial hypertension.arterial hypertension.

9. ARTERIAL BLOOD PRESSUREARTERIAL BLOOD PRESSURE
is determined by cardiac output and
peripheral vascular resistance. The
kidney plays a key role in its control.
•Excretion of salt and water controls
intravascular volume, which influences
the forces of contraction of the heart.
•Excretion of renin influences vascular
tone and electrolyte balance.

10. •IncreasedIncreased: peripheral vessel resistance,: peripheral vessel resistance,
cardiac output, tone of sympathetic nervouscardiac output, tone of sympathetic nervous
system, synthesis of AII, aldosterone, ETs.system, synthesis of AII, aldosterone, ETs.
•InhibitedInhibited synthesis of NO, kinins, PGE, PGIsynthesis of NO, kinins, PGE, PGI22..
Arterial bloodArterial blood
pressurepressure >>>>>>
120/80 mm Hg120/80 mm Hg
at restat rest

15. HypertensionHypertension
of white apronof white apron

16. SHRSP

17.  Drugs acting on the RAASDrugs acting on the RAAS

19. a) ACE inhibitors
•Competitive inhibition of ACE reduces
generation of AT II and release of aldo-
sterone. Inhibition of tissue ACE in the vas-
scular wall is more important for the hypo-
tensive effect of these drugs than its action
on the circulating renin-angiotensin system.
•Reduced tissue concentrations of AT
lead to arterial and venous dilation.

20. Angiotensinogen
Angiotensin I
Angiotensin II
Aldosterone
release
Kininogen
Bradykinin
Degradation
products
Renin
Kallikrein
ACE(kininaseII)

21. Angiotensin II and ACE inhibitors
•Captopril
•Cilazapril
•Enalapril
•Fosinopril
•Lisinopril
•Perindopril
•Ramipril
•Trandolapril

22. CAPTOPRIL
(prodrug)
(prodrug)

23. Unwanted effects:
•Cough: unproductive;
may be due to accumulation of kinins in the
lung; occurs up to 10–20 % of patients
(more common in women!).
•Postural hypotension (some-
times after the first dose)
•Disturbances of taste, K+
•Rashes, angioneurotic edema
•Teratogenicity (PRC: D)
AH, CHD, atherosclerosis, DM, sclerodremal crisis
ACE inhibitors – used in:

24. Losartan Irbesartan Valsartan
b) AT1-blockers (sartans)
Oral: in a once daily dosing regimen.
Expensive, but with small ARs.

25. AT1-antagonists differ from ACE inhibitors in the
following ways (by Tripathy, 2003):
• They do not interfere with degradation of kinins
(so no rise in level or potentiation of bradykinin).
• They block completely AT1-receptors and therefore
alternative pathways of AT generation do not have
any importance.
• They result in indirect AT2-receptor activation.
ACE inhibitors result in depression of both AT1-
and AT2-activation.

26. (β1) (β1 & β2 )
Bopindolol
Propranolol
Oxprenolol (β1 ISA)
Pindolol (with β1 ISA)
Carvedilol
(antioxidant)
Labetalol
(β & α)
 Drugs acting on the SNSDrugs acting on the SNS
a) Beta-blockers
Atenolol
Acebutolol (β1 ISA)
Bisoprolol
Celiprolol (β2 ISA)
Metoprolol
Nebivolol releases NO

27. Mechanism of antihypertensive effect
•Blockade of β1-adrenoceptors in heart
reduces heart rate and
myocardial contractility.
•Blockade of renal juxtaglomerular β1-
receptors reduces renin secretion.
•Blockade of presynaptc β2-adrenoceptors
inhibits exocytose of NA.
•Carvedilol and labetalol also block
α-receptors and produce vasodilation.

29. VDCC ROCC
Receptor
AP
Ca2+
CaCa2+2+
Sarcoplasmatic
reticulum
Cell
wall
(–)
Beta-blockersBeta-blockers
AP – action potential, NA – noradrenaline
VDCC – voltage dependent calcium channels
ROCC – receptor operating calcium channels
(–)

30. Lipophilic β-blockers (e.g. propranolol) are
well absorbed from the gut, but undergo
extensive first-pass metabolism in the liver,
with considerable variability.
Hydrophilic β-blockers (e.g. atenolol) are
less completely absorbed from the gut and
are eliminated unchanged by the kidney.
The dose range to maintain effective plasma
concentrations is narrower than that of drugs
which undergo metabolism and the clinical
response is more predictable.

31. Adverse reactions of β-blockers
•Blockade of β1-receptors may cause
bradycardia, AV block, heart failure.
•Blockade of β2-receptors may cause
bronchospasm, intermittent claudication
(reducing peripheral blood flow) and
hypoglycemia.
ATP cAMP 3’,5’ AMPACAC PDE
Beta-blockersBeta-blockers
(-)

32. •Most β-blockers raise plasma concentration
of triglycerides and lower concentration of
antiatherogenic HDL (probably β3-effect ?).
•Induratio penis plastica (fibrosis …)
•Sudden withdrawal syndrome:
beta-blockers should be stopped gradually.
Nebivolol
Selective β1-blocker, releases NO (causes vasodialtion)
It has 24 h effect. End Effect/Maximum Effect >90%)
•CNS effects: sleep disturbance, dreams
and hallucinations (more common with
lipophilic drugs which cross the BBB).

33. AtenololAtenolol
BisoprololBisoprolol
MetoprololMetoprolol
NebivololNebivolol
PropranololPropranolol
ββ11//ββ22-blocking-blocking
activityactivity
ββ-blockers-blockers
1515
5050
2525
293293
1,91,9
S e l e c t i v i t yS e l e c t i v i t y
(55(55−−65/min 24 h)65/min 24 h)
(55(55−−65/min 24 h)65/min 24 h)

34. Blockade of postsynaptic α1-receptors
lowers blood pressure by:
•Lowering tone in arteriolar resistance vessels.
•Dilating venous capacitance vessels, which
reduces venous return and cardiac output.
•Selective α1-adrenoceptor antagonists spare
the presynaptic α2-adrenoceptors and do
not produce reflex tachycardia.
b) Postsynaptic α1-blockers

35. Postsynaptic α1-blockers
Doxazosin
Prazosin

36. Prazosin
•It has potentially beneficial effect:
− an increase in HDL;
− a reduction in triglycerides
•Adverse reactions (AR):
− postural hypotensionpostural hypotension due to venous
pooling (this can be troublesome
after the first dose)
− lethargy, toleranstolerans

37. Doxazosin
Indications: arterial hypertension and
hyperplasia of the prostate gland (men > 45 years old)
Selective postsynaptic alpha-1А-blocker:
It blocks alpha-1А-receptors into the smooth muscles of the
prostate gland,
and the
prostatic
part of the
urethra.

38. c) α2a-agonists
There are several different α2-adrenoceptor
subtypes have been identified: α2a, α2b and etc.
α2a-adrenoceptors appear to mediate sedation,
analgesia and hypotension while the
α2b-adrenoceptor mediates vasoconstriction
and hypertension (i.e. postsynaptic
α2-adrenoceptors are probably of the α2b2b subtype).

39. • Clonidine ( HCl)
− xerostomia (dry mouth)
− withdrawal phenomenon
− sedationsedation
− postural hypotension
• Methyldopa
The stimulation of presynaptic α2a-receptors
in CNS inhibits NA release, reduces sym-
pathetic influence on the vasomotor centre;
reduces peripheral arterial and venous tone.
(prodrug: α-methyl-NA is an α2a-agonist)

40. ClonidineClonidine
αα-methyl-NA-methyl-NA
ClonidineClonidine
αα-methyl-NA-methyl-NA
(+)
Dopegyt®
(αα-methyl-DOPA)-methyl-DOPA)
a

41. The stimulation of I1-receptors:
•in CNS reduces sympathetic tone
and lowers blood pressure;
•in kidney inreases secretion of ANP
• Moxonidine
• Rilmenidine
d) I1 (Imidazoline-1)-agonists
(> t1/2: 1 time daily p.o.)

42. e) Adrenergic
neuron
blockers
•Guanethidine
•Reserpine
– Numerous
adverse
reactions
(out of date)
Rauwolfiaserpentina

43. Adrenergic neuron blockers
use the active transport
mechanisms for monoamines to
accumulate in the adrenergic nerve
terminal. Inside the cell they prevent
the release of NA from vesicles.

45.  Calcium antagonistsCalcium antagonists

46. VDCC ROCC
Receptor
AP
Ca2+
Ca2+
Sarcoplasmatic
reticulum
Cell
wall
NA
(–)
Calcium
antagonists
AP – action potential, NA – noradrenaline
VDCC – voltage-dependent calcium channels
ROCC – receptor operating calcium channels

48. CalciumantagonistsCalciumantagonists Amlodipine
norm frequent dihydropyridine
t1/2 31–47 h, 55–91% p.o. bioavailability
5–10 mg/24 h p.o. (once daily)
Nifedipine (tachycardia!)
– effective in vasospastic angina
Diltiazem (in SR dosage forms)
Verapamil (Isoptin SR®
– tabl. 240 mg)
(22% p.o. bioаvailability, first pass effect –
extensive liver metabolism; constipation)

49. Adverse reactions
•Arterial dilation: headache, flushing
and dizziness, ankle edema (resistant
to diuretics)
•Bradycardia and AV block (verapamil
and diltiazem), constipation (verapamil)
•Verapamil has potentially hazardous
additive effects with beta-blockers,
reducing the force of myocardial
contraction and slowing the heart rate.
•Tachycardia (nifedipine, nisoldipine).

50. Gingivitis haemorrhagicaGingivitis haemorrhagica

51. Furosemide
Torsemide
20−30%
Hydrochlorothiazide
Chlorthalidone
Indapamide
5% 3%
Amiloride
Triamterene
Spironolactone
 Diuretics (p.o. in low daily dose)Diuretics (p.o. in low daily dose)
Indapamide
•Vasodilator
•It does not influence
serum level of Na+
,
K+,
Mg2+
and Ca2+

52. ARs of thiazide and thiazide-like diuretics
• Hypokalemia, salt and water
depletion, hyperuricemia, nocturia,
glucose intolerance (dose-related) and
hyperglycemia, hyperlipidemia (increased
LDL and triglycerides), impotence.
In small doses thiazide and loop
diuretics reduce the intracellular
sodium in the smooth muscle of the
resistance vessels, which decreases
responsiveness to vasopressor substances.

53.  Other antihypertensive vasodilatorsOther antihypertensive vasodilators
(used in hypertensive emergencies)(used in hypertensive emergencies)
•Sodium nitroprusside
(direct NO donor): i.v. infusion
•Diazoxide: bolus i.v.
(ADRs: hyperglycemia)
•Nifedipine: sublingually
•Clonidine: sublingually, i.m.
•Nitrolingual®
or Isoket®
spray:
sublingually

54. Nitroprusside is an inorganic nitro-
vasodilator with a mechanism of
action similar to that of organic nitrates.
It is reserved for hypertensive emergencies.
It dilates arterioles and veins, reducing
both peripheral resistance and venous
return. It is given by i.v. infusion and
has a duration of effect of less than 5 min.
Metabolism to cyanide within red blood
cells terminates its effects. ADRs: Confusion,
psychosis, metabolic acidosis.

55. PGE1
•Caverject®
i. cav.
Inhibitors of PD5 (p.o.):
•Sildenafil (Viagra®)
•Tadalafil (Cialis®), Vardenafil
 Rational antihypertensive combinationsRational antihypertensive combinations
•ACE inhibitor + thiazide diuretic
•Sartan + thiazide diuretic
•Beta-blocker + thiazide diuretic
•Beta -blocker + amlodipine or felodipine
Sexual function
Inhibit:
•Diuretics
•Alfa-blockers
•Alfa2-agonists
•Beta-blockers
•Reserpine-like ...
Do not influence:
•ACE inhibitors
•AT1-blockers
•Calcium
antagonists
•Nebivolol

56. Clinical classificationClinical classification
A: ACE inhibitors and ATA: ACE inhibitors and AT11-blockers-blockers
B: Beta-blockersB: Beta-blockers
C: Calcium antagonistsC: Calcium antagonists
D: DiureticsD: Diuretics
PHEOCHROMOCYTOMA
Centrally acting drugs
− α2-agonists
− I1-agonists
Adrenergic neuron blockers

57. ADJUVANT DRUGSADJUVANT DRUGS
•Platelet antiaggregants
•Antidyslipidemic drugs
•Anxiolytics, etc.
NONPHARMACO-NONPHARMACO-
LOGICAL METHODSLOGICAL METHODS
– avoiding of the risk factors

58. •BMI > 30:
>>> saturated fatty acids
>>> salt and >>> sugar
>>> alcohol
<<< fruits and vegetables
•SmokingSmoking
•Lipid statusLipid status
•StressStress
2/32/3
of theof the
riskrisk
Risk factors for CVD
•Chomocysteine > 15 mmol/l

•Diabetes mellitus
•Metabolic syndrome
•Sedentary life styleSedentary life style
•Tachycardia

60. Никотинът е иНикотинът е и
ензимен индуктор.ензимен индуктор.

63. RatingRating
of cardio-of cardio-
vascularvascular
riskrisk