Felodipine
Felodipine. Dihydropyridine CCB — vascular Cav1.2 blockade > cardiac selectivity ratio higher than amlodipine. Once-daily extended-release dosing… Oral half-life 10 h.
Dihydropyridine CCB — vascular Cav1.2 blockade > cardiac selectivity ratio higher than amlodipine. Once-daily extended-release dosing for hypertension. Grapefruit juice raises AUC ~2× via intestinal CYP3A4 inhibition (the canonical grapefruit-DDI example).
PK: the half-life of 10.2 h is verbatim and IS a genuine disposition value, being the terminal phase of a three-phase fit anchored by intravenous dosing. V corrected 700 to 679, the stated 9.7 L/kg scaled to 70 kg, and F corrected 0.15 to the cited paper own 16%. IMPORTANT NON-DEFECT, RECORDED SO IT IS NOT LATER "FIXED": this volume is INTRAVENOUS-DERIVED, so pairing it with an independent bioavailability is correct and is not the apparent-volume double-division it superficially resembles. ka 1 collides with a stated time to peak of 64 minutes. FORMULATION MISMATCH REMAINS: the cited study used an oral SOLUTION plus an intravenous arm, while the marketed product is extended-release with near zero-order erosion, so this parameter set fits neither form exactly — too slow for a solution, far too fast for the tablet. Bioavailability is not a constant for this drug in any case: grapefruit juice raises it from 15% to 45%. The record only reference was a RAT formulation study and is replaced.
Pharmacokinetics
- Oral — t½ 10.2 h · F 16% · Vd 679 L
Sources: PMID:1577050, PMID:2404502