Anti-anginal
An antianginal is a drug used
in the treatment of angina
pectoris, a symptom of ischaemic heart disease.
Drugs used are nitrates, beta
blockers, or calcium channel blockers.
Symptoms:
Chest pain
Pain in your arms, neck, jaw
Nausea
Fatigue
Shortness of breath
Sweating
Dizziness
CLASSIFICATION:
Nitrates:
Short
acting: Glyceryl trinitrate and Isosorbide dinitrate (sublingual).
Long acting: isosorbide
dinitrate and isosorbide mononitrate.
𝛃-Blocker:
Cardioselectives such as acebutolol or metoprolol
Non-cardioselectives such as Oxprenolol or
Sotalol
Calcium
channel Blocker:
Verapamil,
Diltiazem, Amlodipin
Potassium
channel opener:
Nicorandil
Other
anti anginal drugs:
Trimetazidine,
Ranolazine, Jvabradine, Dipyridamole
Mechanism
of action (MOA)
Nitrates: 
Nitrates
↓
Formation
of nitrogen oxide(NO)
↓
Activate
Guanylate cyclase
↓
↑cGMP
↓
Activate
protein kinase
↓
Dephosphorylation
of light chain myosin
↓
Relaxation
of actin myosin
↓
Smooth
muscle relaxation
↓
Vasodilation
Uses:
Angina
pectoris,
Acute
coronary syndromes,
Biliary
Colic
Myocardial
infarction(MI),
Esophageal
spasm,
Cyanide
poisoning
Side Effects:
Headache
tachycardia
𝛃-Blocker:
The Beta adrenergic blockers decrease the oxygen
demands of the myocardium by blocking 𝛃1 receptors, Resulting in decreased heart
rate,Contractility, Cardiac output(CO) and blood pressure.
Side effects:
fatigue, weight gain
shortness of breath
dizziness
headache
upset stomach.
Calcium channel blocker:
There are 2 main calcium channels:
T-type calcium channel blocker:
In the heart pacemaker cells which control the
heart rate, there are T-type calcium channel. Calcium activity in the pacemaker
cells cause the heart to pump faster and increasing the BP.
By using the T-type calcium channel blockers it
will block calcium activity. And thus decrease heart rate, decrease cardiac
output and then decrease blood pressure.
L-type calcium channel blocker:
It is found on smooth muscle cells.
Blood vessel which contain smooth muscles, L-type
calcium channels allow influx of calcium into the muscle filaments which will
cause contraction and this will increase BP. by using L-type calcium
channel blocker block calcium channel. thus smooth muscle will relax and
decrease BP.
Dose:
Verapamil: 40-160 mg TDS oral, 5 mg by slow
i.v. injection.
(Interactions: Verapamil should not be given with
13 blockers)
(It should not be used along with other cardiac
depressants like quinidine and disopyramide)
Adverse effects:
Constipation
Bradycardia
nausea
Diltiazem:
It is somewhat less potent vasodilator than nifedi
pine and verapamil.
Dose: 30- 60 mg TDS-QID oral; DILZEM, 30, 60 mg
tabs.
Adverse effect:
Similar to verapamil
Amlodipin:
Dose: 5-
10 mg OD
Felodipine:
Dose: 5-
10 mg OD, max. 10 rng BD.
Nitrendipine:
Dose: 5-
20 mg OD; NITREPI . CARDff 10, 20 mg tabs.
Potassium
channel opener:
Nicorandil:
Potassium
Channel Opener
↓
Open KATP
↓
Enhance Kᐩ efflux
↓
Membrane
Hyperpolarization
↓
↓ Ca ᐩᐩ entry
↓
Reduced
intracellular Calcium
↓
Smooth
muscle Relaxation
These are
the drugs that activate (open) ATP sensitive potassium channel in vascular
smooth muscle. Opening of these channels, hyperpolarizes the smooth muscle,
which closes voltage-gated calcium channel and decrease intracellular calcium,
leading to muscle relaxation and vasodilatation, Decreasing vascular resistance
and decrease blood pressure.
Dose: 5-20 mg BO
Side effects:
flushing
palpitation
weakness
headache
dizziness
nausea
and vomiting
Other anti anginal drugs:
Trimetazidine:
Dose: 20mg TDS
Ranolazine:
Dose: 0.5-1 g BD
Dose: 20mg TDS
Ranolazine:
Dose: 0.5-1 g BD