An
antianginal is any
drugA pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
used in the treatment of
angina pectoris, a symptom of
ischaemic heart diseaseCoronary artery disease is the end result of the accumulation of atheromatous plaques within the walls of the coronary arteries that supply the myocardium with oxygen and nutrients...
.
Nitrates cause
vasodilationVasodilation refers to the widening of blood vessels resulting from relaxation of smooth muscle cells within the vessel walls, particularly in the large arteries, smaller arterioles and large veins. The process is essentially the opposite of vasoconstriction, or the narrowing of blood vessels. When...
of the venous capacitance vessels by simulating the
endothelium-derived relaxing factorEndothelium-derived relaxing factor is produced and released by the endothelium that results in smooth muscle relaxation. The most well characterized is nitric oxide , and some older sources consider the two terms to be equivalent....
(EDRF). Used to relieve both exertional and vasospastic angina by allowing venous pooling, reducing the pressure in the ventricles and so reducing wall tension and oxygen requirements in heart. Short-acting nitrates are used to abort angina attacks that have occurred, while longer-acting nitrates are used in the prophylactic management of the condition.
Agents include
nitroglycerinNitroglycerin , also known as nitroglycerine, , trinitroglycerin, trinitroglycerine, 1,2,3-trinitroxypropane and glyceryl trinitrate, is a heavy, colorless, oily, explosive liquid obtained by nitrating glycerol...
(glyceryl trinitrate) or pentaerythritol tetranitrate.
Beta blockers are used in the prophylaxis of exertional angina by reducing the work the heart is allowed to perform below the level that would provoke an angina attack.
They cannot be used in vasospastic angina and can precipitate heart failure.
Agents include either cardioselectives such as
acebutololAcebutolol is a beta blocker for the treatment of hypertension and arrhythmias.-Pharmacology:Acebutolol is a cardioselective beta blocker with ISA...
or
metoprololMetoprolol is a selective β
1 receptor blocker used in treatment of several diseases of thecardiovascular system, especially hypertension...
, or non-cardioselectives such as
oxprenololOxprenolol is a non-selective beta blocker with some intrinsic sympathomimetic activity. It is used for the treatment of angina pectoris and abnormal heart rhythms...
or
sotalolSotalol is a drug used in individuals with rhythm disturbances of the heart, and to treat hypertension in some individuals.Sotalol is a non-selective beta blocker...
.
CalciumCalcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft grey alkaline earth metal, and is the fifth most abundant element by mass in the Earth's crust...
ionAn ion is an atom or molecule where the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge...
(Ca
++) antagonists (
Calcium channel blockerCalcium channel blockers are a class of drugs and natural substances that disrupt the conduction of calcium channels.It has effects on many excitable cells of the body, such as cardiac muscle, i.e. heart, smooth muscles of blood vessels, or neurons...
s) are used in the treatment of both exertional and vasospastic angina.
An
antianginal is any
drugA pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
used in the treatment of
angina pectoris, a symptom of
ischaemic heart diseaseCoronary artery disease is the end result of the accumulation of atheromatous plaques within the walls of the coronary arteries that supply the myocardium with oxygen and nutrients...
.
Nitrates
Nitrates cause
vasodilationVasodilation refers to the widening of blood vessels resulting from relaxation of smooth muscle cells within the vessel walls, particularly in the large arteries, smaller arterioles and large veins. The process is essentially the opposite of vasoconstriction, or the narrowing of blood vessels. When...
of the venous capacitance vessels by simulating the
endothelium-derived relaxing factorEndothelium-derived relaxing factor is produced and released by the endothelium that results in smooth muscle relaxation. The most well characterized is nitric oxide , and some older sources consider the two terms to be equivalent....
(EDRF). Used to relieve both exertional and vasospastic angina by allowing venous pooling, reducing the pressure in the ventricles and so reducing wall tension and oxygen requirements in heart. Short-acting nitrates are used to abort angina attacks that have occurred, while longer-acting nitrates are used in the prophylactic management of the condition.
Agents include
nitroglycerinNitroglycerin , also known as nitroglycerine, , trinitroglycerin, trinitroglycerine, 1,2,3-trinitroxypropane and glyceryl trinitrate, is a heavy, colorless, oily, explosive liquid obtained by nitrating glycerol...
(glyceryl trinitrate) or pentaerythritol tetranitrate.
Beta blockers
Beta blockers are used in the prophylaxis of exertional angina by reducing the work the heart is allowed to perform below the level that would provoke an angina attack.
They cannot be used in vasospastic angina and can precipitate heart failure.
Agents include either cardioselectives such as
acebutololAcebutolol is a beta blocker for the treatment of hypertension and arrhythmias.-Pharmacology:Acebutolol is a cardioselective beta blocker with ISA...
or
metoprololMetoprolol is a selective β
1 receptor blocker used in treatment of several diseases of thecardiovascular system, especially hypertension...
, or non-cardioselectives such as
oxprenololOxprenolol is a non-selective beta blocker with some intrinsic sympathomimetic activity. It is used for the treatment of angina pectoris and abnormal heart rhythms...
or
sotalolSotalol is a drug used in individuals with rhythm disturbances of the heart, and to treat hypertension in some individuals.Sotalol is a non-selective beta blocker...
.
Calcium channel blockers
CalciumCalcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft grey alkaline earth metal, and is the fifth most abundant element by mass in the Earth's crust...
ionAn ion is an atom or molecule where the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge...
(Ca
++) antagonists (
Calcium channel blockerCalcium channel blockers are a class of drugs and natural substances that disrupt the conduction of calcium channels.It has effects on many excitable cells of the body, such as cardiac muscle, i.e. heart, smooth muscles of blood vessels, or neurons...
s) are used in the treatment of both exertional and vasospastic angina. In vitro, they dilate the coronary and peripheral arteries and have negative inotropic and chronotropic effects - decreasing
afterloadIn cardiac physiology, afterload is used to mean the tension produced by a chamber of the heart in order to contract. If the chamber is not mentioned, it is usually assumed to be the left ventricle. However, the strict definition of the term relates to the properties of a single cardiac myocyte...
, improving myocardial efficiency, reducing
heart rateHeart rate is determined by the number of heartbeats per unit of time, typically expressed as beats per minute , it can vary with as the body's need for oxygen changes, such as during exercise or sleep. The measurement of heart rate is used by medical professionals to assist in the diagnosis and...
and improving coronary blood flow.
In vivo, the vasodilation and
hypotensionIn physiology and medicine, hypotension refers to an abnormally low blood pressure. This is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the opposite of hypertension, which is high blood...
trigger the
baroreceptorBaroreceptors are sensors located in the blood vessels of the human body. They detect the pressure of blood flowing through them, and can send messages to the central nervous system to increase or decrease total peripheral resistance and cardiac output...
reflex. Therefore the net effect is the interplay of direct and reflex actions.
- Class I antiarrhythmic agents have the most potent negative inotropic effect and may cause heart failure.
- Class II agents do not depress conduction or contractility.
- Class III agent has negligible inotropic effect and causes almost no reflex tachycardia
Tachycardia comes from the Greek words tachys and kardia . Tachycardia typically refers to a heart rate that exceeds the normal range for a resting heartrate...
.
Examples include Class I agents (
e.g.,
verapamilVerapamil is an L-type calcium channel blocker of the phenylalkylamine class. It has been used in the treatment of hypertension, angina pectoris, cardiac arrhythmia, and most recently, cluster headaches. It is also an effective preventive medication for migraine...
), Class II agents (
e.g.,
amlodipineAmlodipine is a long-acting calcium channel blocker used as an anti-hypertensive and in the treatment of angina...
,
nifedipineNifedipine is a dihydropyridine calcium channel blocker. Its main uses are as an antianginal and antihypertensive, although a large number of other uses have recently been found for this agent, such as Raynaud's phenomenon, premature labor, and painful spasms of the esophagus in cancer and...
), or the Class III agent
diltiazemDiltiazem is a member of the group of drugs known as benzothiazepines, which are a class of calcium channel blockers, used in the treatment of hypertension, angina pectoris, and some types of arrhythmia. It is also an effective preventive medication for migraine. It is a class 3 anti-anginal drug,...
.