Calcium Channel Blockers

Question 1

Types of Calcium Channels

Answer 1

Voltage Gated (activated by depolarization) (--> muscles)
Ligand Gated
Calcium Pump (Active)
Ryanodine
Store Operated
IP3 Receptor

(last three are G protein coupled)

Question 2

Structure of L Type Calcium Channel

Mechanism of Action

Answer 2

2 alpha, beta, gamma, Delta (5 subunits)

Binding site: alpha 1–> confirmation change

Use Dependent

Question 3

Pharmacokinetics of Calcium Channel Blockers

Answer 3

Good Oral Absorption
High first pass
High PPB
Metabolised extensively
Excreted renally

Question 4

Side Effects of Calcium Channel Blockers

Answer 4

AV Blockade
Bradycardia
Hypotension
Negative heart effects
Flushing
Dizziness
Prolonged QT--> Torsade Des Pointes
Constipation

Safe during pregnancy, especially nifedipine

Question 5

Indications for Calcium Channel Blockers

Answer 5

Tachyarrythmia
Angina
Hypertension
Congestive HF (decrease pre and after load)
GI Motility disorders (SM relaxation)
Post stroke (decrease cerebral damage)

Question 6

Drug List Calcium Channel Blockers

Dihydropyridines vs Non Dihydropyridines

Answer 6

Verapamil (never combo with beta blocker)

Amlodipine
Nifedipine
Nitrendipine
Nimodipine

Diltiazem