Mechanism of Action:
- Block L-type calcium channels in vascular smooth muscle and cardiac myocytes.
- Results in:
- Vasodilation: Lowers BP (DHPs)
- Decreased contractility & heart rate: Benefits angina & heart failure (non-DHPs)
Clinical Uses:
- Hypertension (DHPs): Amlodipine, nifedipine, felodipine (1st line for most)
- Angina (non-DHPs): Verapamil, diltiazem
- Supraventricular arrhythmias (non-DHPs): Verapamil (e.g., atrial fibrillation)
- Raynaud’s phenomenon (DHPs): Nifedipine
Adverse Effects:
- Common: Dizziness, fatigue, headache, flushing, ankle swelling (generally mild)
- Non-DHP specific: Bradycardia & heart failure (susceptible individuals)
Contraindications:
- Severe heart failure
- Sick sinus syndrome
- Advanced atrioventricular block
Key Points:
- Choose based on indication & patient.
- DHPs are generally well-tolerated, non-DHPs require caution in specific populations.
- Monitor for drug interactions.
- Stay updated on evolving roles in cardiovascular medicine.