Felodipine

Drug Information: Felodipine

Detailed information regarding Felodipine, a dihydropyridine calcium channel blocker primarily used in the treatment of hypertension. It works by selectively inhibiting calcium influx into vascular smooth muscle cells, causing vasodilation and a reduction in blood pressure. Felodipine is often formulated as an extended-release tablet to provide consistent blood pressure control throughout the day. Because of its selectivity for vascular smooth muscle, it has less direct effect on cardiac contractility and conduction compared to some other calcium channel blockers.

Category

Antihypertensive

Mechanism of Action

Felodipine is a dihydropyridine calcium channel blocker. Its primary mechanism of action involves selectively blocking L-type calcium channels in vascular smooth muscle cells. L-type calcium channels are voltage-dependent and play a critical role in regulating calcium influx into cells. When vascular smooth muscle cells are depolarized, these channels open, allowing calcium ions to enter the cell. This influx of calcium triggers a cascade of events that ultimately leads to muscle contraction and vasoconstriction.

By blocking these channels, Felodipine reduces the intracellular calcium concentration in vascular smooth muscle cells. This, in turn, inhibits the contractile process, leading to vasodilation. Felodipine exhibits a greater affinity for vascular smooth muscle compared to cardiac muscle, which contributes to its potent antihypertensive effects with relatively less impact on cardiac contractility and conduction. The reduced vascular resistance results in a decrease in blood pressure. Furthermore, the drug’s extended-release formulation ensures a gradual and sustained reduction in blood pressure, minimizing abrupt changes that could trigger reflex tachycardia.

Clinical Uses

Felodipine is primarily indicated for the management of hypertension (high blood pressure). It is effective in reducing both systolic and diastolic blood pressure. It can be used alone or in combination with other antihypertensive agents, such as diuretics, ACE inhibitors, or beta-blockers, to achieve optimal blood pressure control. Additionally, Felodipine may be used off-label for the treatment of certain forms of angina, particularly vasospastic angina (Prinzmetal’s angina), due to its vasodilatory effects on coronary arteries. Its use in angina management may be limited by the availability of other, more specific anti-anginal medications. It is generally administered orally as an extended-release tablet to provide a sustained release of the drug over 24 hours, ensuring consistent blood pressure control.

Dosage

Adults: The usual starting dose of Felodipine is 2.5 mg to 5 mg orally once daily, typically taken as an extended-release tablet. The dosage can be adjusted based on the patient’s blood pressure response, usually at intervals of one to two weeks. The maximum recommended dose is 10 mg once daily.

Pediatric: The safety and efficacy of Felodipine in pediatric patients have not been firmly established. Consult a healthcare professional for pediatric dosage recommendations.

Route of Administration: Oral. Felodipine is available as an extended-release tablet, which should be swallowed whole and not crushed or chewed.

Indications

* Hypertension (High Blood Pressure)
* Off-label use: Vasospastic Angina (Prinzmetal’s Angina)

Contraindications

* Hypersensitivity to Felodipine or other dihydropyridine calcium channel blockers.
* Severe hypotension.
* Cardiogenic shock.
* Advanced aortic stenosis.
* Unstable angina.
* During pregnancy and breastfeeding (generally avoided due to potential risks).

FAQ

Q: What is Felodipine used for?
A: Felodipine is primarily used to treat hypertension (high blood pressure). It may also be used off-label for vasospastic angina.

Q: How does Felodipine work?
A: Felodipine is a calcium channel blocker that works by relaxing blood vessels, which helps to lower blood pressure.

Q: What are the common side effects of Felodipine?
A: Common side effects may include headache, flushing, peripheral edema (swelling in the ankles and feet), and dizziness.

Q: Can I take Felodipine with other medications?
A: It’s important to inform your doctor about all the medications you are taking, as Felodipine can interact with other drugs.

Q: How should I take Felodipine?
A: Felodipine is usually taken orally once daily as an extended-release tablet. Follow your doctor’s instructions carefully.

Q: What should I do if I miss a dose of Felodipine?
A: If you miss a dose, take it as soon as you remember, unless it’s almost time for your next dose. In that case, skip the missed dose and continue with your regular dosing schedule. Do not double the dose to catch up.

Q: Are there any dietary restrictions while taking Felodipine?
A: Grapefruit and grapefruit juice can interact with Felodipine, increasing the amount of the drug in your bloodstream and potentially increasing side effects. It’s best to avoid grapefruit and grapefruit juice while taking this medication.

Q: Who should not take Felodipine?
A: Felodipine is contraindicated in patients with hypersensitivity to Felodipine, severe hypotension, cardiogenic shock, advanced aortic stenosis, and unstable angina. It should generally be avoided during pregnancy and breastfeeding.