Nifedipine

Nifedipine is a Dihydropyridine Calcium Channel Blocker (DHP CCB).

It primarily causes arterial vasodilation and reduces systemic vascular resistance.

Used in:

• Hypertension
• Stable Angina
• Vasospastic angina
• Raynaud phenomenon

→ Calcium Channel Blockers

Nifedipine blocks L-type calcium channels in vascular smooth muscle.

This leads to:

• ↓ Intracellular calcium
• Arterial vasodilation
• ↓ Systemic Vascular Resistance
• ↓ Afterload

Minimal direct effect on:

• SA node
• AV node
• Myocardial contractility

Primary action = vascular.

Immediate-Release (short-acting):

• Rapid vasodilation
• Reflex tachycardia
• Not recommended for chronic hypertension
• Associated with increased risk of adverse cardiac events

Extended-Release (preferred):

• Smooth 24-hour BP control
• Lower risk of reflex tachycardia
• Appropriate for chronic hypertension and angina

Extended-release formulations are standard in modern practice.

• ↓ Blood pressure
• ↓ Afterload
• Possible reflex tachycardia (especially short-acting form)

Does NOT significantly:

• Slow heart rate
• Depress AV conduction

Hypertension:

• Extended-release formulation preferred
• Often combined with:
  • ACE Inhibitors
  • ARBs
  • Thiazide Diuretics

Angina:

• Reduces afterload
• Improves oxygen supply-demand balance

Vasospastic Angina:

• Coronary vasodilation

Raynaud Phenomenon:

• Reduces vasospasm

Common:

• Peripheral edema
• Flushing
• Headache
• Reflex tachycardia (short-acting)

Mechanism of edema:

• Arteriolar dilation without venodilation
• Increased capillary hydrostatic pressure

Avoid short-acting formulation in:

• Unstable angina
• Acute coronary syndromes

Use caution in:

• Severe hypotension

Amlodipine:

• Longer half-life
• Less reflex tachycardia
• More gradual onset

Nifedipine:

• Faster onset
• Greater reflex tachycardia risk (short-acting)

• DHP CCB
• Strong arterial vasodilator
• Use extended-release for chronic therapy
• Avoid short-acting form in CAD
• Causes peripheral edema
• No AV nodal slowing

• Calcium Channel Blockers
• Dihydropyridines
• Amlodipine
• Hypertension
• Anti-Anginal Therapy