This drug may cause dizziness, fatigue, nausea and headache, if affected, do not drive or operate machinery.
Monitor blood pressure and heart rate. Monitor blood pressure and heart rate. Assess for development of peripheral oedema.
Symptoms: Excessive peripheral vasodilation with marked hypotension, bradycardia. Management: Symptomatic treatment. Administration of activated charcoal and perform gastric lavage within 1 hour of ingestion. For severe hypotension, elevate legs and place patient in supine position. In case of bradycardia, 0.5-1 mg atropine IV may be given, if insufficient, plasma volume may be increased by infusion. May consider sympathomimetic agents based on clinical decision.
Increased plasma concentrations with CYP3A4 inhibitors (e.g. cimetidine, erythromycin, itraconazole, ritonavir). Decrease plasma concentrations with CYP3A4 inducers (e.g. phenytoin, carbamazepine, rifampicin, barbiturates, efavirenz). May increase serum concentration of tacrolimus.
Increased plasma concentration with high-fat meal. Increased plasma concentration with grapefruit or grapefruit juice. Decreased plasma concentration with St. John’s wort.
May result to false-negative aldosterone/renin ration (ARR).
Description: Felodipine, a dihydropyridine Ca-channel blocker, produces coronary vascular smooth muscle relaxation and coronary vasodilation by inhibiting the entry of Ca ions in select voltage-sensitive areas of vascular smooth muscle and myocardium during depolarisation. It also increases myocardial oxygen delivery in cases of vasospastic angina. Onset: 2-5 hours. Duration: 24 hours. Pharmacokinetics: Absorption: Almost completely absorbed from the gastrointestinal tract. Increased plasma concentration with high fat meal. Bioavailability: Approx 15%. Time to peak plasma concentration: 2.5-5 hours. Distribution: Enters breast milk. Plasma protein binding: >99%. Metabolism: Undergoes extensive hepatic first-pass metabolism by CYP3A4 enzyme. Excretion: Via urine (approx 70% as metabolites), faeces (10%). Elimination half-life: 11-16 hours (immediate release).