Felodipine
Plendil · Felodipin Teva · Felodipin Stada · Logimax
A highly vascular-selective dihydropyridine given as a modified-release tablet once daily for hypertension and stable angina. The selectivity for vascular smooth muscle means felodipine lacks the nodal effects of verapamil and diltiazem — no bradycardia, no AV block, and no clinically significant negative inotropy, making it combinable with beta-blockers. The price of pure vasodilatation is dependent oedema, which is dose-related and the most common reason for discontinuation.
The modified-release tablet must be swallowed whole — if split or crushed the full dose is released at once and can cause marked hypotension with reflex tachycardia. In patients with critical aortic stenosis or obstructive cardiomyopathy, vasodilatation may cause circulatory collapse.
Dosing in adults
| Indication | Regimen | Comment |
|---|---|---|
| Hypertension | 5 mg modified-release tablet × 1 in the morning; increase to 10 mg × 1 if needed | evaluate no earlier than after 2 weeks |
| Stable angina pectoris | 5 mg × 1, increase to 10 mg × 1 if needed | adjunct to beta-blockers, not a replacement |
| Elderly or reduced hepatic function | 2,5 mg × 1 as starting dose | risk of orthostatic hypotension and falls |
| Dependent oedema on 10 mg | reduce to 5 mg and add an ACE inhibitor or ARB | RAAS blockade reduces oedema; diuretics do not |
| Insufficient effect of monotherapy | felodipine 5 mg + metoprolol succinate 47,5–95 mg | combination tablet available |
No dose adjustment required — the metabolites are inactive and elimination is in practice independent of renal function. Not dialysed due to high protein binding.
Clearance decreases substantially and plasma concentration may increase several-fold. Start at 2,5 mg daily and titrate slowly; in severe hepatic failure the drug should generally be avoided.
Insufficient documentation in children and adolescents — felodipine is not recommended in patients under 18 years.
Do not treat the dependent oedema with furosemide — it is haemodynamic and results from precapillary dilatation, not volume excess, so diuretics cause only dehydration and electrolyte disturbance without reducing the oedema. Reduce the dose or add RAAS blockade instead. Also avoid felodipine when the patient needs rate control; verapamil or diltiazem is the right calcium channel blocker in that situation.
Pharmacokinetics
- BIOAVAIL.
- approximately 15 % (extensive first-pass)
- t½
- approximately 25 h in the terminal phase
- Tmax
- 3–5 h (modified-release formulation)
- PROTEIN BINDING
- > 99 %
- METABOLISM
- CYP3A4, inactive metabolites
- EXCRETION
- Approximately 70 % renal as metabolites, remainder via faeces
- DURATION
- > 24 h with modified-release tablet
- INOTROPY
- no clinically significant negative effect