The primary purpose of Felodipine is to support the management of conditions related to systemic imbalance in blood pressure and vascular function. It is commonly used to help manage two main therapeutic areas, assisting with maintaining functional stability for the patient; specifically, the medication is used for managing high blood pressure.

Felodipine is commonly used across conditions presenting with acute episodes of essential hypertension (chronic high blood pressure). This condition involves symptoms related to heightened physiological activity where the force of blood against the arteries is persistently too high. By addressing the force of blood against the arteries, the medication assists with maintaining functional stability by lowering blood pressure. Its primary indications are essential hypertension and chronic stable angina.

This provides support that helps ease the overall symptom burden of hypertension and contributes to easing the overall symptom load associated with long-term cardiovascular stress. It is also considered relevant for easing symptoms related to physical discomfort that cluster into patterns of chronic stable angina pectoris. Therapy in this domain is relevant when supportive symptom management is appropriate and aims to assist with maintaining functional stability.

---

Quick Fact: Relief for Anginal Chest Discomfort

Felodipine plays a role in managing chronic stable angina, which is applied in addressing the imbalance that leads to episodic chest discomfort. This offers symptomatic relief that helps patients cope more steadily with symptom fluctuations during periods of exertion.

Regulatory References

1. NIH MedlinePlus overview

Eligibility Map: Who can and cannot use Фелодипин (Felodipine) — official regulatory information

---

Eligibility scope

Classification	Population/Condition
Populations for whom use is allowed	Adults for hypertension and stable angina; Patients with renal impairment.
Populations for whom use is not recommended	Individuals with hepatic impairment (liver disease) due to reduced drug clearance. Lactating individuals.
Populations for whom use is contraindicated	Known hypersensitivity to Felodipine; Acute cardiovascular states, including unstable angina pectoris, acute myocardial infarction, and decompensated heart failure; Pregnancy.
Age-related eligibility rules	Safety and efficacy have not been established in the pediatric population. Older adults may require special consideration due to age-related changes.

---

Eligibility classifications (high-level)

Classification Type	Examples as defined in official documents
Eligibility severity classification	Contraindicated; Not Established; Use with Caution; Generally Acceptable.
Regulatory basis	EMA Summary of Product Characteristics and FDA Prescribing Information.

---

Resulting eligibility structure

Official eligibility statements:

• Use is formally contraindicated in pregnancy and in specific acute cardiovascular conditions.
• Safety is not established for use in children.
• Use requires caution in patients with hepatic impairment due to increased drug concentration.

Connection to the overall eligibility profile (2–4 sentences): Regulatory documents establish that Felodipine is intended for use by the adult population under standard conditions. The profile formally prohibits use for individuals with specific severe heart conditions, known hypersensitivity, or those who are pregnant. All other limitations are based on organ function, such as hepatic impairment, or the regulatory declaration that safety is not established in the pediatric population or during lactation.

Interactions with other medicines and products

The interaction profile of Felodipine is predominantly defined by its metabolism through the CYP3A4 enzyme system, leading to pharmacokinetic interactions that significantly alter its plasma concentration. These interactions are formally documented in regulatory labeling.

---

Pharmacokinetic Interactions (Exposure Modification)

Felodipine exposure can be substantially modified by medicines and substances that affect the CYP3A4 enzyme:

• CYP3A4 Inhibitors: Co-administration with potent or moderate inhibitors, such as itraconazole or erythromycin, can cause a significant increase in Felodipine's plasma levels (up to an 8-fold increase in AUC with itraconazole). This effect is due to reduced metabolic clearance.
• CYP3A4 Inducers: Co-administration with enzyme inducers, including rifampicin or the herbal product St. John's Wort, decreases Felodipine concentrations. This results from increased metabolic clearance and can lead to a loss of the required blood pressure control.

---

Pharmacodynamic and Substance Interactions

• Other Antihypertensive Agents: Concurrent use with other agents intended to lower blood pressure, such as beta-blockers or diuretics, may result in an additive hypotensive effect.
• Grapefruit Juice: Consumption of grapefruit juice is documented to cause a significant increase in Felodipine’s systemic exposure by inhibiting its presystemic metabolism.

---

Interaction Notes

No combinations are formally listed as contraindicated in the FDA prescribing information. The pharmacokinetic interaction with grapefruit juice is documented as potentially more pronounced and sustained in the elderly population.

Blocking Calcium Channels in Blood Vessel Walls

Felodipine is a dihydropyridine agent that acts by modulating processes governing the contraction of vascular tissue. Its action centers on directly and selectively blocking the L-type voltage-gated calcium channels ( Cav1.x) found in the smooth muscle cells of the arterioles. This interaction stabilizes the channel in its inactive state, inhibiting the influx of extracellular calcium ions ( Ca^2+). By inhibiting the rise in internal calcium, the drug suppresses the molecular signal required to initiate the contraction of the blood vessel wall.

⬇️ Reducing Peripheral Vascular Resistance (PVR)

The cellular relaxation caused by calcium inhibition results in a wide-scale widening of the arterioles, known as vasodilation. This physiological event significantly decreases the Peripheral Vascular Resistance (PVR), which is the total drag or force opposing the flow of blood through the circulatory system. This reduction in resistance decreases the afterload on the heart, resulting in a systemic reduction of pressure on the vessel walls.

️ Engaging the Baroreceptor Reflex Loop

The systemic change in pressure, caused by vasodilation, is recognized by pressure sensors in the body, triggering a compensatory autonomic feedback mechanism called the baroreceptor reflex. This reflex increases sympathetic nerve activity to oppose the pressure change, a mechanistic constraint that can sometimes result in a temporary, reflexive increase in heart rate (reflex tachycardia).

Official Administration Guidelines

Felodipine is administered exclusively by the oral route as an Extended-Release Tablet, a formulation designed to ensure the gradual release of the active compound over a 24-hour period. The drug is taken once daily, typically in the morning.

The established adult initial dose for hypertension and angina is 5 mg once daily. Maintenance dosing ranges from 5 mg to 10 mg once daily, with the maximum standard dose generally being 10 mg once daily. Dose adjustments, if necessary, should only be considered at intervals of at least two weeks.

---

Administration Requirements and Constraints

The tablets must be swallowed whole with water and must not be divided, crushed, or chewed under any circumstances, as this compromises the intended prolonged-release action. Administration may occur either without food or following a light meal low in fat and carbohydrates, with guidance emphasizing consistency in the timing relative to meals. Beverages containing grapefruit juice must be avoided during therapy.

For specific populations, it is recommended to consider a reduced starting dose of 2.5 mg once daily for older adults and patients with hepatic impairment. No dose adjustment is generally required for renal impairment.

If a dose is missed, instructions are to take it as soon as remembered. However, if it is almost time for the next scheduled dose, the missed dose must be skipped, and a double dose must never be taken.

Фелодипин: Recent Clinical Evidence

Clinical trials have primarily focused on confirming the role of felodipine (a dihydropyridine calcium channel blocker) in the management of essential hypertension (high blood pressure) and chronic stable angina pectoris.

Efficacy in Approved Indications

Research continues to support felodipine's established role in reducing blood pressure. Studies have demonstrated that extended-release felodipine monotherapy can significantly lower both systolic and diastolic blood pressure in patients with mild-to-moderate hypertension. In particular, trials involving older patients with isolated systolic hypertension have shown that felodipine treatment is associated with achieving lower blood pressure targets compared to placebo and may reduce the incidence of left ventricular hypertrophy.

For chronic stable angina, clinical data suggest that felodipine can improve exercise tolerance and may be associated with a reduction in the frequency of angina attacks. It is often evaluated as a supplementary treatment for patients already using beta-blockers, where it can provide additional blood pressure reduction and improve certain hemodynamic parameters.

Tolerability and Safety Findings

Felodipine is generally considered well-tolerated in many adult populations. Common adverse events observed in trials are typically related to its potent vasodilatory action. The most frequently reported adverse effects include headache, flushing, and peripheral edema (swelling, particularly in the ankles and feet), which are often dose-dependent. Studies have also noted that peripheral edema may be more common in elderly patients or those on higher doses.

Researchers continue to investigate the drug's safety profile in specific patient groups, such as those with co-existing conditions like liver or kidney impairment, as felodipine is extensively metabolized in the liver.

Common questions about Фелодипин (FAQ)

Q: How is Фелодипин different from other common high blood pressure medicines (like ACE inhibitors)?

Felodipine is classified as a Calcium Channel Blocker (CCB), a type of medicine that works by relaxing the blood vessels. This mechanism is different from drugs like ACE inhibitors or diuretics, which work in other ways. Official clinical studies indicate that its effectiveness in lowering blood pressure is comparable to these other common antihypertensive agents.

Q: How long do common side effects like headaches and dizziness typically last when starting Фелодипин?

According to official product information, common side effects such as headache and flushing are often linked to the start of treatment or following a dose adjustment. These effects are generally short-lived and tend to decrease over time, often resolving within the first week of starting the medication.

Q: What are the possible signs of an allergic reaction to Фелодипин?

Signs of a hypersensitivity reaction (allergic reaction) may include the development of a rash, hives, or swelling of the face, tongue, or lips, which could potentially cause difficulty breathing. Official regulatory documents specify that serious reactions, such as angioedema, require immediate medical attention.

Q: Is it true that the effects of Фелодипин are immediate or do they build up over time?

A reduction in blood pressure generally begins within two to five hours after taking the extended-release tablet. The concentration of the medicine in the blood continues to increase until a steady state is reached, and maximum concentrations (Cmax) are typically higher after multiple doses compared to a single dose.

Q: What happens to blood pressure when the effect of a single dose wears off?

The extended-release formulation is specifically designed to provide effective blood pressure control that lasts for approximately 24 hours. Official studies indicate that blood pressure remains significantly reduced even at the end of the dosing interval, maintaining control throughout the day.

Q: Is Фелодипин a long-term treatment or is it only for short-term use?

Felodipine is intended for the control and management of chronic conditions, such as high blood pressure and stable angina. Because hypertension and angina are typically chronic, long-term conditions, the medication is generally used as a continuous, sustained therapy.

Q: Is Фелодипин a diuretic or 'water pill'?

No, Felodipine is classified as a Calcium Channel Blockers (CCB), not a diuretic (water pill). However, official product documents note that some patients may experience mild diuresis (increased urine flow) during the initial week of taking the medication.

Q: Is there a risk of weight gain while taking Фелодипин?

Official regulatory reporting indicates that unusual or rapid weight gain has been reported as a side effect in clinical trials. If these changes are experienced, consulting a healthcare professional is generally recommended, as these symptoms can also be associated with other conditions.

Q: Can Фелодипин cause problems with sleep, such as insomnia?

Insomnia, which includes sleeplessness or having trouble falling or staying asleep, is reported as a possible side effect in the official safety information for this medication.

Q: Does Фелодипин affect vision or cause blurred sight?

Regulatory safety documentation lists blurred vision as a possible side effect. Other visual disturbances, such as double vision or changes in color perception, have also been reported.

Q: What should be done if side effects of Фелодипин do not go away?

If any side effects persist, become worse, or are bothersome, official patient information suggests consulting with a doctor or pharmacist for guidance.

Q: Can the medication cause tingling sensations or 'pins and needles'?

Yes, tingling sensations in the hands or feet, known medically as paresthesia, are reported as a side effect in regulatory documents. This effect is classified as common in some official safety profiles.

Q: What happens if I consume alcohol while taking Фелодипин?

The combination of alcohol and Felodipine may enhance the blood pressure-lowering effect. This interaction could lead to symptoms such as dizziness, lightheadedness, or fainting.

Q: Does Фелодипин interact with over-the-counter pain relievers or fever reducers?

Official guidance indicates that combining Felodipine with any medicine that also lowers blood pressure, including some over-the-counter products, may result in an additive hypotensive effect (lowering blood pressure too much). It is generally recommended to consult a healthcare professional about specific pain relievers.

Q: Does Фелодипин interact with medications used for epilepsy or seizures?

Yes, certain anticonvulsant medications, such as carbamazepine, are known to interact with Felodipine. This interaction can substantially decrease the concentration of Felodipine in the body, which may lead to a loss of the required blood pressure control.

Q: Are all drug interactions with Фелодипин serious, or are some mild?

Drug interactions are formally categorized by their clinical significance as Major, Moderate, or Minor. This categorization reflects the potential risk when combined with Фелодипин, and the approach to management varies depending on the category.

Q: How long does it take for Фелодипин to start working to lower blood pressure?

Official product documents indicate that a reduction in blood pressure generally begins within two to five hours after the extended-release tablet is administered.

Q: How will I know if Фелодипин is working if I don't feel any different?

It is common for a person to not feel any noticeable difference when taking medication to control high blood pressure. Official patient information confirms that not feeling different does not necessarily mean the medicine isn't working; its effectiveness is primarily measured by regular blood pressure readings.

Q: Can I stop taking Фелодипин once my blood pressure is at a healthy level?

Felodipine should not be stopped abruptly, even if blood pressure appears to be controlled. Hypertension is often a chronic condition requiring continuous therapy, and official patient information advises consulting with a healthcare professional before making any changes to the treatment plan.

Q: What is the evidence base or research supporting the long-term use of Фелодипин?

The long-term use of Felodipine is supported by clinical data, including studies that have confirmed the sustained efficacy and tolerability of the drug over periods of up to one year. This research validates its established role in the continuous management of chronic conditions.

Q: Are there specific studies about Фелодипин and its effect on stroke risk?

Yes, clinical research suggests that the blood pressure-lowering effect of Felodipine, when used to treat hypertension, can contribute to a decreased incidence of stroke associated with high blood pressure.

Q: Does poor dental hygiene make the side effect of swollen gums more likely?

Gingival swelling (gum enlargement) is a reported side effect of this class of medicine. Clinical studies suggest that the condition has a multifactorial cause, and improving oral hygiene is considered a key management strategy to help control its development or severity.

Storage and Disposal of Felodipine

Felodipine extended-release tablets must be stored at room temperature, typically between 20 C and 25 C (68 F and 77 F), according to regulatory guidelines. The medicine must be kept away from excess heat and moisture, protected from direct light, and must not be allowed to freeze.

Storage Requirement	Rule
Container	Keep in the closed, tightly closed container
Child Safety	Keep out of the reach of children

For disposal, the official instruction is to ask your healthcare professional (pharmacist or doctor) how to discard any unused or outdated medicine. Disposal of the product must be done in accordance with local requirements and methods that avoid release to the environment, particularly into wastewater.