2.6.2 Calcium-channel blockers (CCBs)

CCBs are divided into two subtypes which have important pharmacological differences:

1. Rate-limiting non-dihydropyridine CCBs – verapamil and diltiazem – which are negatively inotropic and should be avoided in heart failure or reduced left ventricular function
2. Dihydropyridine CCBs – amlodipine, felodipine, lacidipine, lercanidipine, nicardipine, nifedipine and nimodipine

Hypertension

Choice	Drug
1st choice	Amlodipine tablets 5mg, 10mg
2nd choice	Lercanidipine tablets 10mg, 20mg

Angina

Choice	Drug
1st choice CCB (patient taking a beta-blocker)	Amlodipine tablets 5mg, 10mg
1st choice CCB (in patients unable to tolerate a beta-blocker)	Diltiazem m/r tablets 60mg, 90mg, 120mg; m/r capsules 90mg, 120mg, 180mg, 200mg, 240mg, 300mg, 360mg Prescribe by brand name

Supraventricular arrhythmias – to be used under secondary care guidance only

Choice	Drug
1st choice	Verapamil m/r tablets 120mg, 240mg Prescribe by brand name*
*patients switched between brands due to medicines shortages may require closer monitoring of BP in the initial stages

Prescribing Notes

• The commonest problem with amlodipine is ankle oedema, which may necessitate stopping as the oedema responds poorly to leg elevation or diuretics.
• A switch to lercanidipine may be reasonable to try if a patient develops ankle oedema with amlodipine.
• Felodipine m/r is still a reasonable choice, and there is no need to switch patients already stable on felodipine m/r.
• The treatment of patients currently receiving concomitant simvastatin 40 mg and amlodipine or diltiazem should be reviewed at their next routine appointment. Switch to atorvastatin 20mg and monitor lipid levels to ensure lowest necessary dose of atorvastatin is used. See MHRA and 2.12 lipid regulating drugs .
• The rate limiting CCBs diltiazem or verapamil may be considered for angina or following myocardial infarction if a beta-blocker cannot be used.
• Diltiazem and verapamil have negative inotropic effects and should be avoided in patients with LV dysfunction or heart failure.
• A long-acting formulation should be used if diltiazem is prescribed. Different versions of modified-release preparations may not have the same clinical effect. Therefore prescribe by brand, taking care to prescribe either the once or twice daily option as appropriate.
• Diltiazem should only be used under specialist advice if given with beta-blockers due to risk of bradycardia.
• Verapamil may be used to treat supraventricular arrhythmias or occasionally, atrial fibrillation (see section 2.3.2).
• The combination of a beta-blocker and verapamil should only be used under specialist advice because bradycardia, asystole, severe hypotension, and heart failure can occur. It must be avoided in patients with heart block or heart failure.
• Standard release nifedipine may be harmful and is no longer recommended for angina or hypertension.