Felodipine

Oral
Angina pectoris

Oral
Hypertension

Initially, 2.5 mg daily. Monitor blood pressure during titration.

May be taken with or without food. Take w/o food or w/ a light meal. Avoid grapefruit juice.

Decompensated heart failure, acute myocardial infarction, unstable angina pectoris, significant cardiac valvular obstruction, cardiac outflow obstruction. Pregnancy.

Patient with pronounced gingivitis/periodontitis, severe aortic stenosis, heart failure, hypertrophic cardiomyopathy with outflow tract obstruction. Hepatic impairment. Elderly. Lactation.

Significant: Tachycardia, myocardial ischaemia, peripheral oedema, angina, rarely, hypotension with or without syncope.
Cardiac disorders: Palpitations.
Gastrointestinal disorders: Nausea, abdominal pain, vomiting, mild gingival hyperplasia.
General disorders and admin site conditions: Fatigue.
Investigations: Very rarely, increased hepatic enzymes.
Nervous system disorders: Headache, dizziness.
Vascular disorders: Flushing.

PO: C

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:
Mechanism of Action: 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).

Source: National Center for Biotechnology Information. PubChem Database. Felodipine, CID=3333, https://pubchem.ncbi.nlm.nih.gov/compound/Felodipine (accessed on Jan. 20, 2020)

Store below 30°C. Protect from light.

Anti-Anginal Drugs / Calcium Antagonists

C08CA02 - felodipine ; Belongs to the class of dihydropyridine derivative selective calcium-channel blockers with mainly vascular effects. Used in the treatment of cardiovascular diseases.

Anon. Felodipine. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 01/04/2019.

Buckingham R (ed). Felodipine. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 01/04/2019.

Felodipine (Glenmark Pharmaceuticals, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 01/04/2019.