Most Used 8 Calcium Channel Blockers: Action Uses Dosage Side Effect by Nurses Note

 Calcium Channel Blockers

Uses of  Calcium Channel Blockers

Treatment of essential hypertension, treatment of and prophylaxis of angina pectoris (including vasospastic, chronic stable, unstable), prevention/control of supraventricular tachyarrhythmias, prevention of neurologic damage due to subarachnoid haemorrhage.

Action  Calcium Channel Blockers

Calcium channel blockers inhibit the flow of extracellular Ca2+ ions across cell membranes of cardiac cells, vascular tissue. They relax arterial smooth muscle, depress the rate of sinus node pacemaker, slow AV conduction, decrease heart rate, produce negative inotropic effect (rarely seen clinically due to reflex response). Calcium channel blockers decrease coronary vascular resistance, increase coronary blood flow, reduce myocardial oxygen demand. Degree of action varies with individual agent.

Calcium Channel Blockers

1. Amlodipine

Availability: Tab, 2.5 mg, 5 mg, 10 mg.

Indication: HTN, Angina.

Dosage

• HTN: Initially 2.5-5 mg once daily. May titrate q7-14 days up to 10 mg/day.
• Angina: 5-10 mg once daily.

Side Effects: Headache, peripheral oedema, dizziness, flushing, rash, tachycardia.

2.Diltiazem

Availability: Tab- 30mg, 60mg, 90mg, 120mg, Extended Release: 120mg, 180mg, 240mg, 300mg, 360mg, 420mg.

Cap: (SR-12HR): 60mg, 90mg, 120mg, (ER-24HR): 120mg, 180mg, 240mg, 300mg, 360mg, 420mg

IV: 5mg/mL.

Indications

• PO: HTN, Angina
• IV: Arrhythmias

Dosage

• HTN: 120-540 mg/day
• Angina: 120-480 mg/day
• IV: 20-25mg IV bolus, then 5-15 mg/hr infusion.

Side Effects: Constipation, flushing, hypotension, dizziness, AV block, bradycardia.

3. Felodipine

Availability: Tab- 2.5mg, 5mg, 10mg.

Indication: HTN

Dosage: Initially 5mg/day. May increase q2wks, usual dose: 5-10mg/day.

Side Effects: Headache, peripheral oedema, dizziness, flushing, rash, tachycardia.

4. Isradipine

Availability: C- 2.5mg, 5mg

Indication: HTN

Dosage: Initially 2.5mg 2 times/day. May increase at 2-4 wk intervals at 2.5-5 mg increments. Usual dose 5-10 mg 2 times/day.

Side Effects: Headache, peripheral oedema, dizziness, flushing, rash, tachycardia.

5. Nicardipine

Availability:

• C (IR): 20mg, 30mg.
• C (ER): 30mg, 45mg, 60mg
• I: 2.5 mg/mL

Indications: HTN, Angina.

Dosage: HTN/Angina- Initially, 20-30mg 3 times/ day. May increase q3days. Usual dose: 20-40 mg 3times/day.

Side Effects: Headache, peripheral oedema, dizziness, flushing, rash, tachycardia.

6. Nifedipine

Availability

• C (IR): 10mg, 20mg.
• T (ER): 30mg, 60mg, 90mg.

Indications: HTN, Angina.

Dosage: HTN (ER)- Initially 30-60mg once daily. Usual dose: 90-120mg once daily. Angina: (IR): 10-20mg tid or (ER): initially 30-60mg once daily. Titrate up to 90mg daily, maximum 120mg.

Side Effects: Headache, peripheral oedema, dizziness, flushing, rash, tachycardia.

7. Nimodipine

Availability

• Cap: 30mg
• Syrup: 60 mg/20mL

Indication: Prevent neurologic damage following subarachnoid haemorrhage

Dosage: 60 mg q4h for 21 days.

Side Effects: Nausea, reduced B/P, headache, diarrhoea.

8. Verapamil

Availability

• Tab (IR): 40mg, 80mg, 120mg.
• Tab (SR): 120mg, 180mg, 240mg.

Indications

• Angina (IR): Initially, 40-120 mg 3 times/day. Usual dose: 80-160 mg tid or (SR): Initially 180 mg at HS. May increase at weekly intervals up to 480 mg/day.
• HTN (IR): Initially 80 mg 3 times/day. Usual dose: 240-480 mg/day in divided doses, (SR): Initially 120-180 mg /day. May increase at wkly intervals to 240 mg/day, then 180 mg 2 times/day. Maximum: 240mg 2 times/day.

Side Effects: Constipation, dizziness, tachycardia, AV block, bradycardia, headache, HF, oedema.

Reference Sounders Pharmacology