1. Anti- anginal drugs

2. content Anti anginal drugs Angina pectoris Types Classification
Nitrates
Calcium channel blockers
b blockers
Combination therapy
content

3. Anti-anginal drugs
Antianginal drugs may relieve attacks of acute myocardial
ischemia by increasing myocardial oxygen supply
or by decreasing myocardial oxygen demand
Three groups of pharmacological agents have
been shown to be effective in reducing the frequency,
severity, or both of primary or secondary angina.
These agents include the nitrates, adrenoceptor antagonists,
and calcium entry blockers.
To understand the beneficial actions of these agents, it is important to be familiar with the major factors regulating the balance between
myocardial oxygen supply and demand.

4. Angina pectoris
It is the principal symptoms of patient with ischemic heart disease.
Manifested by sudden, severe, pressing substernal pain that often radiates to the left shoulder and along the flexor surface of the left arm.
Usually precipitated by exercise, excitement or a heavy meal.

6. Types of angina pectoris

10. nitrates Classification of nitrates: Rapidly acting nitrates
* used to terminate acute attack of angina
* e.g.- Nitroglycerin and Amyl nitrate
* usually administered sublingually
Long acting nitrates
* used to prevent an attack of angina
* e.g. – tetra nitrate, Iso sorbide di nitrate, Penta erythrytol tetra nitrate
* administered orally or topically

11. Organic nitrates & nitrites are simple nitric & nitrous esters of glycerol.
These agents cause a rapid decrease in myocardial oxygen demand leading to rapid resolution of symptoms.
Nitrates are effective for all types of angina.
Activation of guanylate cyclase increases cGMP activating a cGMP kinase leading to dephosphorylation of myosin light chains decreasing contractile force.
Organic nitrates

13. 1st mechanism of action Coronary artery dilatation
Decrease coronary bed resistance
(Relieved coronary vasospasm)
Increase coronary blood flow
Increase oxygen supply

14. 2nd mechanism of action Reduction on peripheral resistance
(Secondary to dilatation of aorta)
Decrease blood pressure
Decrease after load
Decrease workload
Decrease oxygen consumption

15. 3rd mechanism of action Reduced venous return
(Due to dilatation of the veins)
Decrease left ventricular volume
Decrease preload
Decrease workload
Decrease oxygen consumption

17. Route of administration
1. Sublingual route – rational and effective for the treatment of acute attacks of angina pectoris. Half-life depend only on the rate at which they are delivered to the liver.
2. Oral route – to provide convenient and prolonged prophylaxis against attacks of angina
3. Intravenous Route – useful in the treatment of coronary vasospasm and acute ischemic syndrome.
4. Topical route – used to provide gradual absorption of the drug for prolonged prophylactic purpose.

18. Route of administration Duration of action
Drug
Usual single dose
Route of administration
Duration of action
Short acting
Nitroglycerin mg
sublingual
min
Isosorbide dinitrate
2.5-5 mg
10 – 60 min
Amyl nitrite
0.18 – 3 ml
inhalation
3 – 5 min
Long acting
Nitroglycerin sustained action
6.5 – 13 mg q 6-8 hrs
oral
6 – 8 hrs
Nitroglycerin 2% ointment
1 – 1.5 inches q hr
topical
3 – 6 hrs
Niroglycerin slow released
1 –2 mg per 4 hrs
Buccal mucosa
Nitroglycerin slow released
10 – 25 mg /24hrs (one patch/day}
transdermal
8 –10 hrs
2.5 – 10 mg per 2 hrs
1.5 – 2 hrs
10 –60 mg per 4-6 hrs
4 – 6 hrs
Isosorbide dinitrate chewable
5 – 10 mg per 2-4 hrs
2 – 3 hrs
Isosorbide mononitrate
20 mg per 12 hrs
6 –10 hrs

19. effects
1. Coronary artery dilatation 2. Reduction of peripheral arterial resistance – decrease after load 3. Reduce venous return – decrease preload

20. pharmacokinetics
The difference between nitrate preparations is mainly in time of onset of action.
Nitroglycerin suffers marked 1st pass metabolism so administration is sublingual.
t1/2 ~10 minutes.
Occasionally as nitroglycerin is metabolized anginal symptoms will return.
Transdermal administration either as patch or paste provides a depot of agent for a steady availability.
Nitro-Bid is an oral or topical preparation which saturates the hepatic catabolic pathways allowing a prolonged level of nitroglycerine.
Isosorbide mono nitrate & Isosorbide di nitrate are long acting nitrates that are relatively resistant to hepatic catabolism ……t1/2 ~ 1 hour.

21. Adverse effects
1. Throbbing headache 2. Flushing of the face 3. Dizziness – especially at the beginning of treatment 4. Postural Hypotension – due to pooling of blood in the dependent portion of the body

22. contraindications 1. Renal ischemia 2. Acute myocardial infarction
3. Patients receiving other antihypertensive agent

23. Beta- blockers
β-Blockers decrease oxygen demands of the myocardium by lowering the heart rate and contractility (decrease CO) particularly the increased demand associated with exercise.
They also reduce PVR by direct vasodilatations of both arterial & venous vessels reducing both pre- and after load.
These effects are caused by blocking β1 receptors, selective β1 antagonists (atenolol, metoprolol ) lose their selectivity at high doses and at least partially block β2 receptors.

24. β1 antagonists reduce the frequency and severity of anginal episodes particularly when used in combination with nitrates.
β1 antagonists have been shown to improve survival in post MI patients and decrease the risk of subsequent cardiac events & complications.
There are a number of contraindications for β blockers: asthma, diabetes, bradycardia, PVD & COPD.
β-Blockers in combination with nitrates can be quite effective

25. Hemodynamic effect
1. Decrease heart rate 2. Reduced blood pressure and cardiac contractility without appreciable decrease in cardiac output

26. Decrease heart rate & Contractility
Mechanism of action
Decrease heart rate & Contractility
Increase duration of diastole
Decrease workload
Increase coronary blood flow
Decrease oxy.consumption
Increase oxygen supply

27. contraindications
1. Congestive heart failure 2. Asthma 3. Complete heart block

28. Calcium channel blockers
Ca+2 channel blockers protect tissue by inhibiting the entrance of Ca+2 into cardiac and smooth muscle cells of the coronary and systemic arterial beds.
All Ca+2 channel blockers produce some vasodilation (↓ PVR) and (-) inotropes.
Some agents also show cardiac conduction particularly through the AV node thus serving to control cardiac rhythm.
Some agents have more effect on cardiac muscle than others but all serve to lower blood pressure.
CHF patients may suffer exacerbation of their failure as these are (-) inotropes.
They are useful in Prinzmetal angina in conjunction with nitrates.

29. agents
Nifedipine:
This Ca+2 channel blocker works mainly on the arteriolar vasculature decreasing after load it has minimal effect of conduction or HR.
It is metabolized in the liver and excreted in both the urine & the feces.
It causes flushing, headache, hypotension and peripheral edema.
It also has some slowing effect on the GI musculature resulting in constipation.
A reflex tachycardia associated with the vasodilatation may elicit myocardial ischemia in tenuous patients, as such it is generally avoided in non-hypertensive coronary artery disease.

30. verapamil
The agents has its main effect on cardiac conduction decreasing HR and thereby O2 demand.
It also has much more (-) inotropic effect than other Ca+2 channel blockers
It is a weak vasodilator.
Because of its focused myocardial effects it is not used as an antianginal unless there is a tachyarrhythmia. It is metabolized in the liver.
It interferes with digoxin levels causing elevated plasma levels; caution and monitoring of drug levels are necessary wit concomitant use.

31. diltiazem
This agent function similarly to Verapamil however it is more effective against Prinzmetal angina.
It has less effect on HR.
It has similar metabolism and side effects as Verapamil.

32. pharmacokinetics Drugs Onset of action Peak of action Half-life
Nifedipine
20 minutes
1 hour
3-4 hours
Verafamil
1-2 hours
5 hours
8-10 hours
Diltiazem
15 minutes
30 minutes
Nicardifine
45 minutes
2-4 hours
Felodipine
2-5 hours
6-7 hours
11-16 hour

33. Adverse effect Nausea and vomiting Dizziness Flushing of the face
Tachycardia – due to hypotension

34. contraindications Cardiogenic shock Recent myocardial infarction
Heart failure
Atria-ventricular block

35. 1. Nitrates and B-blockers
Combination therapy
1. Nitrates and B-blockers
The additive efficacy is primarily a result of one drug blocking the adverse effect of the other agent on net myocardial oxygen consumption
B-blockers – blocks the reflex tachycardia associated with nitrates
Nitrates – attenuate the increase in the left ventricular end diastolic volume associated with B-lockers by increasing venous capacitance

36. Calcium channel blockers +beta blockers
Useful in the treatment of exertional angina that is not controlled adequately with nitrates and B-blockers
B-blockers – attenuate reflex tachycardia produce by nifedipine
These two drugs produce decrease blood pressure

37. Calcium channel blocker+nitrates
Useful in severe vasospastic or exertional angina (particularly in patient with exertional angina with congestive heart failure and sick sinus syndrome)
Nitrates reduce preload and after load
Ca channels reduces the after load
Net effect is on reduction of oxygen demand

38. Triple drugs:-nitrates+calcium channel blockers+beta blocker
Useful in patients with exertional angina not controlled by the administration of two types of anti-anginal agent
Nifidipine – decrease after load
Nitrates – decrease preload
B-blockers – decrease heart rate & myocardial contractility

40. Anjali kotwal 5th semester b.pharmacy shoolini university
Presented by:
Anjali kotwal 5th semester b.pharmacy shoolini university