National guidance
NICE guidance on stable angina: management recommends calcium-channel blockers as first line treatment.
NICE guidance on hypertension in adults: diagnosis and management recommend calcium-channel blockers as first line treatment for people who are:
- aged 55 or over and do not have type 2 diabetes
- any age and of Black African or African-Caribbean family origin and do not have type 2 diabetes
Neither guidance makes a recommendation on the best choice of calcium channel blocker.
Choosing between products
Amlodipine and MR felodipine are equally effective and have similar contraindications and cautions. The choice should be based on the following factors:
Licensed indications
Both are licensed for the management of chronic stable angina and hypertension. Amlodipine can also be used for vasospastic (Prinzmetal’s) angina.
Individual needs of the person being treated
Consider the person’s preference for treatment, perception of risks, benefits, and expectations.
Swallowing difficulties
Amlodipine is preferred for people with swallowing difficulties as MR felodipine is not suitable for crushing.
Potential medicine interactions
Amlodipine and MR felodipine have a similar medicine interactions profile. See the British National Formulary or the summary of product characteristics for a full list of interactions.
Amlodipine and simvastatin
Amlodipine can have a moderate interaction with simvastatin leading to an increased risk of myopathy and rhabdomyolysis. For people taking amlodipine, prescribe simvastatin at a maximum daily dose of 20mg or consider an alternative statin. This interaction is not known to occur with MR felodipine.
Potential side effects
Amlodipine and MR felodipine have a similar side effect profile. Side effects include but are not limited to headaches, dizziness, ankle swelling and peripheral oedema. Amlodipine may also commonly cause shortness of breath and visual disorders.
Cost
Where possible consider using the most cost-effective choice which will depend on local contract prices.
Switching between products
There may be circumstances when someone needs to switch between amlodipine and MR felodipine.
Switching strategy
The switching advice below is based on a limited number of retrospective observational trials involving people switching treatment from amlodipine to MR felodipine. The principles of this switch can be used in switching people from MR felodipine to amlodipine.
Direct switch
- Prescribe what will be the final dose of the initial medication.
- For the next scheduled dose, substitute with the same dose of the replacement medication.
For example, switch from 10mg amlodipine once daily to MR felodipine 10mg once daily or vice versa.
Monitoring after the switch
Changes in symptom control
Monitor the impact of this switch as there is a risk that some people may experience worsening angina symptoms or hypotension/hypertension.
Review angina symptoms and/or blood pressure people every 2 to 4 weeks after switching and adjust doses if required until they are stabilised on the new medicine.
Continue reviewing angina symptoms and/or blood pressure every 6 to 12 months once stable.
Side effects
Advise people who are switching that they may experience symptoms of headache, dizziness, flushing and swollen ankles.
Further information
The NHS medicines page on amlodipine or MR felodipine has more information including how to manage common side effects.