2. 2
Angina Pectoris
• Symptom (chest pain) experienced
when coronary blood supply is
insufficient to meet myocardial
requirements
3. 3
Angina Pectoris
• Classical (Stable) Angina:
– Exertional angina
– Produced by increased demand on the
heart (e.g. increased activity, emotional
excitement)
– Caused by coronary artery disease
(artherosclerosis); there is fixed
narrowing of coronary arteries
4. 4
Angina Pectoris
• Variant/Prinzmetal’s angina:
– Occurs at rest
– Caused by spasm of the coronary
arteries
– Which may be superimposed on
arteriosclerotic coronary artery disease
5. 5
Angina Pectoris
• Unstable Angina:
– Pain occurs with less exertion and at rest
– Rapid increase in duration and severity of
attacks
– Rupture of artheromatus plaque attracting
platelet deposition & progressive occlusion
with associated coronary vasospasm
6. 6
Drug Classification
• Nitrates:
– Short acting: Glyceryl trinitrate (GTN,
Nitroglycerine)
– Long acting: Isosorbide dinitrate (short
acting by sublingual route)
– Isosorbide mononitrate
8. 8
Classification
• Pottasium Channel Opener:
– Nicorandil
• Others:
– Dipyridamole, Trimetazidine, Ranolazine
To abort or terminate attack: GTN, Isosorbide
dinitrate (sublingual or transdermal)
For prophylaxis: All others
9. 9
NITRATES
• Dilate veins more than arteries
• Preload reduction End diastollic
size and pressure reduced
decreased cardiac work (Laplace law)
• Wall tension= intraventricular
pressure x ventricular radius
10. 10
NITRATES
• Reduction in ventricular radius
decreases the tension that must be
generated in the ventricular wall
hence decreased O2 consumption
• Also reduce afterload
14. Pharmacokinetics
• Highly lipiid soluble, absorbed well
through oral & intestinal mucosa and
skin
• Extensive hepatic metabolism
• Sublingual, transdermal
14
15. Adverse Effects
• Headache: (Cerebral
vasodilatation)Tolerance develops
• Flushing, dizziness. Postural
hypotension
• Methemoglobinemia (Oxidation of
Hb). In high doses, O2 carrying
capacity can be affected in anemic
15
17. 17
Glyceryl trinitrate
(nitroglycerine)
• Volatile liquid absorbed on the inert
matrix of the tablet and rendered
non-explosive
• Stored in tightly closed glass (not
plastic) container lest the drug
should evaporate
18. Glyceryl trinitrate
(nitroglycerine)
• Used to terminate an attack or abort an
imminent one
• Acts within 1-2 mins
• T1/2 = 2 mins
• Duration for as long as in buccal mucosa
• Spit out once action is over
• Sublingual spray recently marketed
18
19. Glyceryl trinitrate
(nitroglycerine)
• May be used for prophylaxis
• Transdermal patch, remove for 8hrs
daily to avoid tokerance
• Transmucosal patch also avilable
• I.V infusion for rapid, steady,
titrable plasma conc.
19
21. Calcium Channel Blockers
• Block Ca2+ channels (L-type that
occur in smooth & cardiac muscle
cells) there by blocking entry into
cells. This leads to:
• Vasodilatation Cardiac
afterload O2 demand
21
22. Calcium Channel Blockers
• Negative inotropic effect
Oxygen demand
• Recovery of channels is blocked by
verapamil & diltiazem ( Depression of
pacemaker activity and conduction)
22
23. Calcium Channel Blockers
• Verapamil mainly affects the heart;
nifedipine has a greater effect on
smooth muscles than the heart
diltiazem is intermediate in its
actions
23
24. Pk
• Well absorbed orally
• High first pass metabolism
• On chronic use verapamil decreases its
own metabolism
• Highly plasma protein bound
• T1/2 ranges from: 2-6hrs, but that of
amlodipine is exceptionally long
24
26. Adverse Effects
• Ankle oedema with chronic use – due
to increased capillary pressure from
arteriolar dilatation (nifedipine)
• Constipation (Verapamil)
• Risk of heart failure or heart block
with verapamil and dilitiazem
26
27. Drug Interactions
• Reduced effect with hepatic enzyme
inducers
• Increased with --------
• Aggravation of AV block with heart
failure with β-blockers
27
28. USES
• Angina Pectoris
• Cardiac arrhythmias (Verapamil &
Diltiazem) highly effective in PSVT and in
supraventricular arrhythmias
• Hypertrophic cardiomyopathy (Negative
inotropic action of verapamil can be
salutary in this condition
28
29. Other Uses
• Nifedipine is an alternative drug for
premature labour
• Verapamil has been used to suppress
migraine and nocturnal leg cramps
• Raynaud’s (DHP)
29
30. Drugs
• Nifedipine:
• Has effect on veins
• Less –ve inotropy and chronotropy
compared to verapamil
• Verapamil:
• Has some venodilator effect
30
31. Drugs
• Marked –ve inotropy & chronotropy,
therefore avoid in bradycardia and heart
block (Second and third degree)
• Dilitiazem:
• Has less myocardial depression than
verapamil
• Amlodipine:
• Long acting can be given once daily
31
32. β-Blockers
• Blockade of cardiac β1receptor -
ve inotropy and chronotropy
reduced cardiac oxygen demand
• Cardioselective preffered e.g.
atenolol, metoprolol
32
38. Newer Drugs
• K+ channel openers:
• Leads to outflow of K+ since intracellular
concentration is higher
• This leads to hyperpolarisation
• Prominent action is smooth muscle
relaxation
– Nicorandil
38
39. Nicorandil
• Also acts as NO donor
• Both arteriolar and venodilator
• ADRs:
• Flushing, palpitations, weakness,
headache, dizziness, nausea,
vomiting, painful aphthous ulcers in
mouth
39
