Amlodipine (Norvasc)
A long-acting calcium channel blocker used to lower blood pressure and prevent angina. Once-daily dosing, generally well tolerated — ankle swelling is the most common reason for switching.
What it's used for
Hypertension (alone or combined with other drugs), stable angina, coronary artery spasm.
Typical dosing (adults)
- Starting: 2.5-5mg once daily.
- Range: 5-10mg daily.
- With or without food, same time each day.
Key interactions
- Simvastatin (≥20mg): major — raises simvastatin levels; dose limited to 20mg when combined.
- Grapefruit juice: moderate — can raise amlodipine levels modestly.
- Cyclosporine, tacrolimus: moderate — raised immunosuppressant levels.
- CYP3A4 inhibitors (clarithromycin, itraconazole): moderate — may raise amlodipine levels.
Common side effects
Ankle/foot swelling (peripheral edema) — most common, often dose-dependent, doesn't respond well to diuretics. Flushing, headache, dizziness. Less commonly: fatigue, palpitations.
Who should be cautious
- Severe heart failure (use with caution).
- Severe liver disease (start at lower dose).
- Significant ankle swelling that impacts quality of life (consider switching).
What to ask your pharmacist
- My ankles are swelling — is that from amlodipine?
- Does amlodipine interact with my statin?
- Is it okay to drink grapefruit juice?