Felodipine

Felodipine(中文:非洛地平) is a dihydropyridine calcium-channel blocker. It is used in the management of hypertension and angina.

Pronunciation

Felodipine extended-release 2.5mg

Generic Name:	Felodipine
Brand Name:	PLENDIL
Class:	Cardiovascular Drug
Subclass:	Calcium-channel Blocker, CCB
Legal Classification:	P1S1S3

Drug Names

Generic Name 藥物化學名稱	HA Code 藥物代碼	Legal Classification法律藥物分類	Brand Name 品牌名稱
Felodipine Extended-Release Tablet 2.5mg	FELO03	P1S1S3	ADALAT RETARD TABLET
Felodipine Extended-Release Tablet 5mg	FELO01	P1S1S3	ADALAT RETARD TABLET

Mechanism of Action

Felodipine relaxes and widens blood vessels. It does this by blocking calcium going into muscles in the heart and blood vessels. Muscles need calcium to contract, so when you block the calcium, it makes the muscle cells relax. This lowers your blood pressure and makes it easier for your heart to pump blood around your body.

In angina, nifedipine works by improving the blood and oxygen supply to your heart. Angina is chest pain that comes on when not enough blood gets to the muscles of the heart. This usually happens because the arteries going to the heart become hardened and narrowed.

Route of Administration

Felodipine is given orally in an extended release formulation once daily.

Dosage

Agina

• BY MOUTH
• Adult: 5 mg daily, increased if necessary to 10 mg daily.

Hypertension

• BY MOUTH
• Adult: i5 mg daily, usual maintenance 5 – 10 mg once daily.

Elderly:initially 2.5 mg daily, to be taken in the morning; usual maintenance 5 – 10 mg once daily.

Side Effects

The following definitions of frequencies are used:

Very common ≥ 1/10

Common ≥ 1/100 to < 1/10

Uncommon ≥ 1/1,000 to < 1/100

Rare ≥ 1/10,000 to < 1/1,000

Very rare < 1/10,000

System Organ Class	Frequency	Adverse reactions
Nervous system disorder	Common	Headache
Cardiac disorders	UnCommon	Tachycardia, palpitations
Vascular disorders	Common	Flushing
Gastro-intestinal disorders	UnCommon	Abdominal pain, nausea, constipation
	Very rare	Gum hyperplasia
General disorders	Common	Peripheral oedema

Pharmacokinetics

<_>Absorption</_> After an oral dose, peak blood concentrations occur after 6 to 12 hours.

The bioavailability varies but is usually about 60 to 65%.

Amlodipine is reported to be about 98% bound to plasma proteins. It has a prolonged terminal elimination half-life of 35 to 50 hours and steady-state plasma concentrations are not achieved until after 7 to 8 days of use.

Amlodipine is extensively metabolized in the liver; metabolites are mostly excreted in urine, with less than 10% of a dose as unchanged drug.

How long does amlodipine take to work?

Amlodipine starts to work on the day you start taking it, but it may be a couple of weeks before it takes full effect.

Simvastatin:	Co-administration of multiple doses of 10 mg of amlodipine with 80 mg simvastatin resulted in a 77% increase in exposure to simvastatin compared to simvastatin alone. Limit the dose of simvastatin in patients on amlodipine to 20 mg daily.
Contraindication:	cardiogenic shock, significant aortic stenosis, unstable angina