antihypertensive drugs

1. Calcium channel
blockers
Symposium on :
Antihypertensive drugs..
Presented by :
AASHNA
DHINGRA
Roll no. 03

2.  INTRODUCTION
 CLASSIFICATION
 MECHANISM OF
ACTION
 PHARMACOLOGICAL
ACTIONS
 PHARMACOKINETICS
 USES
 ADVERSE EFECTS
 CONTRAINDICATIONS
Layout of the presentation :

3. INTRODUCTION..
also known as calcium antagonists.
 prevent calcium from infiltrating the cells of the
heart and blood vessel walls.
relaxes and widens blood vessels of the heart
within the arterial walls, promoting lowered blood
pressure.
may also slow the heart rate, relieve chest
pressure and control an irregular heartbeat.

4.  they are first line antihypertensive drugs.
 the onset of antihypertensive action is quick.
 monotherapy with CCBs is effective in about
50% of the hypertensives.
 can also be used for treating angina.

5.  PHENYLAKYLAMINES
Verapamil
Very
 1,4-DIHYDROPYRIDINES
 Nifedipine
Nice
 BENZOTHIAZEPINES
Diltiazem

6. 1,4 dihydopyrimidines are selective for the
arteriolar beds.
The phenylalkylamines and
benzothiazepines are selective
for the atrioventricular node.

7. Short-acting
• nifedipine, dilatiazem, verapamil
Long-acting
• amlodipine, felodipine, isradipine,
nicardipine, nisoldipine,

8. Mechanism of action..
o Calcium channels are of 5 subtypes-
L, N, T, P, and R.
o L-type in cardiac and smooth muscle cells.

9. Moa :
CCBs block voltage sensitive
L- type Ca channels by binding
to specific site on the α-1
subunit.
Prevent entry of Ca into cell.
No excitation-coupling
reaction in heart and vascular
smooth muscles.

10.  Increase the time that Ca2+ channels
are closed.
 Relaxation of the arterial smooth
muscle.
 Significant reduction in afterload.
 Coronary vasodilatation.
PHARMACOLOGICAL ACTIONS..

11. PHARMACOKINECTICS..
 well absorbed through Git.
 first pass metabolism.
 highly bound to plasma proteins.
 metabolised in liver.
 excreted through urine.

12. USES OF CCBs..
1. angina pectoris - Due to decrease in myocardial oxygen
consumption, and dilatation of coronary arteries.
2. supraventicular arrhythmias - because of its
depressant action on S-A and A-V nodes.
3. hypertension - they control blood pressure by their
vasodilatory effect.
4. Migraine
5. raynaud’s phenomenon - due to their vasodilatory
property.

13. ADVERSE EFFECTS..
 Postural hypotension
 palpitation
 reflex tachycardia
 edema
 dizziness
 constipation
 sedation
 A-V block
 headache
 fatigue
 lowered B.P.

14. CONTRAINDICATIONS
o Heart failure
o Bradycardia
o Atrioventricular block.
o Dihydropyridine calcium-channel blockers
should not be used in people with uncontrolled
heart failure.

15. SUMMARY..

16. THANK YOU