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 calcium channel blocker (patient taking a beta-blocker)	Amlodipine tablets 5mg, 10mg
1st choice calcium channel blocker (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 most common problem with amlodipine is ankle oedema, which may necessitate stopping as the oedema responds poorly to leg elevation or diuretics.
• A trial of lercandipine may be reasonable 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 [preferred] (see section 2.12) or reduce simvastatin to 20 mg per day. 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. To avoid confusion between these different formulations of diltiazem, prescribers must specify the brand to be dispensed.
• Diltiazem should only be used with secondary care guidance when 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).
• Verapamil should not be used with beta-blockers as concomitant use can result in extreme bradycardia. It must be avoided in patients with heart block or heart failure.
• Short-acting dihydropyridines (e.g. standard release nifedipine) may be harmful and these are no longer recommended for angina or hypertension.