Calcium-Channel Blockers Flashcards
Why should calcium channel blockers (with the exception of amlodipine) be avoided in heart failure? (2)
- They can further depress cardiac function and exacerbate symptoms.
- They can also increase mortality after myocardial infarction in patients with left ventricular dysfunction and pulmonary congestion
What are the indications for Verapamil hydrochloride? (5)
- Treatment of supraventricular arrhythmias
- Paroxysmal tachyarrhythmias
- Angina
- Hypertension
- Prophylaxis of cluster headache (initiated under specialist supervision)
What is the dosing of Verapamil for the treatment of supreventricular arrhythmias by PO and IV in adult and elderly people?
PO:
40–120 mg 3 times a day for Adult
IV:
- 5–10 mg, to be given over 2 minutes, preferably with ECG monitoring for Adult
- 5–10 mg, to be given over 3 minutes, preferably with ECG monitoring
What is the dosing of Verapamil for the treatment of Paroxysmal tachyarrhythmias by IV in adult and elderly people?
Adult:
- 5–10 mg, followed by 5 mg after 5–10 minutes if required, to be given over 2 minutes, preferably with ECG monitoring.
Elderly:
- 5–10 mg, followed by 5 mg after 5–10 minutes if required, to be given over 3 minutes, preferably with ECG monitoring.
What is the dosing of Verapamil for the treatment of Angina by PO?
Adult:
- 80–120 mg 3 times a day.
What is the dosing of Verapamil for the treatment of Hypertension by PO?
Adult:
- 240–480 mg daily in 2–3 divided doses.
What is the dosing of Verapamil for the treatment of Prophylaxis of cluster headache (initiated under specialist supervision)
Adult:
- 240–960 mg daily in 3–4 divided doses.
What are the contraindications for Verapamil? (8)
- Acute porphyrias
- Atrial flutter or fibrillation associated with accessory conducting pathways (e.g. Wolff-Parkinson-White-syndrome);
- Bradycardia;
- Cardiogenic shock;
- Heart failure (with reduced ejection fraction);
- History of significantly impaired left ventricular function (even if controlled by therapy);
- Hypotension;
- Second- and third-degree AV block
What are the common Side Effects for Verapamil? (9)
- Abdominal pain;
- Dizziness & Drowsiness;
- Flushing;
- Headache;
- Nausea & Vomiting
- Palpitations;
- Peripheral oedema;
- Skin reactions;
- Tachycardia;
Is Verapamil negatively or positively ionotrpoic?
Negative
- reduces cardiac output
- slows heart rate
- may impair atrioventricular conduction
What are the indications for Nifedipine?
- Raynaud’s syndrome
- Angina prophylaxis (not recommended)
- Postponement of premature labour
- Hiccup in palliative care
- Chronic anal fissure
What is the dosing of Nifedipine for the treatment of Raynaud’s syndrome by PO?
Initially 5 mg 3 times a day, then adjusted according to response to 20 mg 3 times a day.
What is the dosing of Nifedipine for the treatment of Angina prophylaxis (not recommended) by PO?
Initially 5 mg 3 times a day, then adjusted according to response to 20 mg 3 times a day.
What is the dosing of Nifedipine for the treatment of Postponement of premature labour by PO?
Initially 20 mg, followed by 10–20 mg 3–4 times a day, adjusted according to uterine activity.
What is the dosing of Nifedipine for the treatment of Chronic anal fissure by PR and PO?
PR:
Apply 2–3 times a day until pain stops. Max. duration of use 8 weeks, apply to anal canal, using 0.2%–0.5% topical preparation.
PO:
20 mg twice daily until pain stops. Max. duration of use 8 weeks.
What are the contraindications of Nifedipine? (5)
With systemic use:
- Acute attacks of angina;
- Cardiogenic shock;
- Significant aortic stenosis;
- Unstable angina;
- Within 1 month of myocardial infarction
What are the common side effects of Nifedipine?
- Constipation;
- Malaise;
- Oedema;
- Vasodilation
What are the effects of Nifedipine in pregnancy?
May inhibit labour
Avoid use before week 20
Use only if other treatment options are not indicated or have failed
What could a patient expect if they ceased treatment of Calcium Channel Blockers completely and immediately?
Sudden withdrawal of calcium-channel blockers may be associated with an exacerbation of myocardial ischaemia
What are the indications for Diltiazem hydrochloride?
Prophylaxis and treatment of angina:
- 60 mg PO 3 times a day; max 360 mg per day
Chronic anal fissure
- 60 mg PO BD until pain stops. Max duration 8 weeks
- 2% topical preparation BD until pain stops. Max duration 8 weeks
What are the contraindications of Diltiazem hydrochloride? (8)
Acute porphyrias;
Cardiogenic shock;
Heart failure (with reduced ejection fraction);
Left ventricular failure with pulmonary congestion;
Second- or third-degree AV block (unless pacemaker fitted);
Severe bradycardia;
Sick sinus syndrome;
Significant aortic stenosis
What are the common side effects for all Calcium Channel Blockers? (11)
Abdominal pain;
Dizziness;
Drowsiness;
Flushing;
Headache;
Nausea;
Palpitations;
Peripheral oedema;
Skin reactions;
Tachycardia;
Vomiting
What are the indications and dose of Amlodipine?
Prophylaxis of Angina:
- 5mg OD PO, maximum 10 mg per day
Hypertension:
- 5 mg OD PO maximum 10 mg per day
What are the contraindications for Amlodipine?
Cardiogenic shock
Significant aortic stenosis
Unstable angina
What could happen with a sudden withdrawal of calcium channel blockers?
An exacerbation of Myocardial Ischaemia
What are the indications and dose of Felodipine?
Prophylaxis of Angina
- 5 mg OD PO, increased to 10 mg OD, taken in the morning
Hypertension
- 5 mg OD PO, usual maintenance 5-10 mg OD
What are the contraindications for Felodipine? (5)
Cardiac outflow obstruction
Significant cardiac valvular e.g. aortic stenosis
Uncontrolled heart failure
Unstable angina
Within 1 month of MI
