Felutam CR: Medicine to treat high blood pressure and angina

2021-07-04 06:16 PM

Felutam CR is a selective slow calcium channel blocker of the dihydropyridine class. At low concentrations, it inhibits calcium entry into smooth muscle cells. Thus, felodipine acts on electrophysiological and mechanical processes.

Ingredient

Each tablet: Felodipine 5 mg.

Describe

Film-coated tablets are round white, with small holes on the surface.

Pharmacological

Felodipine is a selective slow calcium channel blocker of the dihydropyridine class. At low concentrations, it inhibits calcium entry into smooth muscle cells. Therefore, felodipine acts on electrophysiological and mechanical processes (inhibiting the excitatory-contractile pair), thus reducing arterial tone, leading to a vasodilator effect that lowers blood pressure. Dilatation of arterioles has increased arterial diameter and maintained, sometimes even increased blood flow in the region (coronary artery, kidney, brain), mild diuretic, sodium excretion, no water retention and salt during long-term treatment. Due to its high selectivity for arteriolar smooth muscle, felodipine at therapeutic doses has no direct effect on the heart, particularly on myocardial contractility or conduction. Contrary to acute treatment, long-term treatment does not increase heart rate.

Felodipine has an antianginal effect by improving the balance of myocardial oxygen supply and demand, coronary artery flow, and myocardial oxygen supply by increasing coronary artery dilation. Felodipine reduces systemic blood pressure, thereby reducing left ventricular afterload, thereby reducing myocardial oxygen demand.

Felodipine increases exercise capacity and reduces the number of angina episodes in patients with stable angina. The drug can be used alone or in combination with a beta-blocker. As with other calcium blockers, felodipine has no effect on glucose and lipid metabolism and does not alter the ratio of components between plasma lipids. Felodipine can be used for people with diabetes or gout.

Pharmacokinetics

As a controlled-release tablet, felodipine is completely absorbed and undergoes extensive first-pass metabolism, with a bioavailability of approximately 20%. After taking the drug 2.5-5 hours, the drug reaches the maximum concentration in the blood plasma. The curve shows maximum plasma concentration over time (AUC) at 20 mg and is increased with dose. Felodipine is >99% bound to albumin. Because the half-effect concentration of felodipine is 4-6 nmol/L, so depending on the individual patient giving felodipine 5-10 mg or oral felodipine 20 mg, the effect will last 24 hours before gradually decreasing the effectiveness. . The plasma concentrations of felodipine increase with age, with the mean elimination rate in elderly hypertensive patients (mean age 74 years) equal to 45% of young patients (mean age 26 years). Steady-state AUC of young patients was 39% of that of the elderly. The bioavailability of felodipine is affected by food. When high-fat food or normal carbohydrate-containing food was used, the maximum concentration (Cmax) increased by 60%, no curve was observed when drinking orange juice, eating toast and cereals and did not affect the pharmacokinetic profile of felodipine. If you drink grape juice or eat grapefruit, it will increase the tolerability of felodipine by 2 times. In hypertensive patients after oral administration of felodipine, maximum plasma concentrations were 20% higher than when blood pressure was stable. The antihypertensive effect is related to the plasma concentration of felodipine. The elimination rate of the drug in patients with impaired liver function was 60% compared with normal young subjects who received the drug. Patients with impaired renal function do not change the plasma concentration curve, but due to decreased urine output, plasma concentrations of the (inactive) metabolite are increased. Animal experiments have shown that the drug crosses the blood-brain barrier and the placenta.

Indications and uses

Treatment of hypertension (can be used alone and/or concurrently with other antihypertensive agents).

Treatment of angina pectoris.

Dosage and Administration

Take in the morning, swallow whole with water, do not split, crush or chew. It can be taken on an empty stomach or after a light meal that is not high in fat or carbohydrates.

Treatment of high blood pressure

Dosage is adjusted according to the individual patient. Treatment should be initiated with 5 mg as a single daily dose. If necessary, the dose can be increased or another antihypertensive agent added. The usual maintenance dose is 5 mg - 10 mg, once a day. For elderly patients, an initial dose of 2.5 mg/day should be considered.

Treatment of angina pectoris

The dose should be adjusted according to the individual patient. Treatment should begin with 5 mg once daily, increasing to 10 mg once daily if neccessary.

Warning

1. Felodipine can cause severe hypotension and syncope, causing reflex tachycardia. Hypersensitive patients may experience angina, hypotension should be used with caution.

2. Patients with heart failure and impaired cardiac function should use caution when using this drug, pay attention to the muscle-weakening effect of this drug, especially when used in combination with beta-blockers.

3. Caution should be exercised when giving this medicine to children. Elderly (over 65 years old) or patients with impaired liver function, treatment must be started from a low dose (1 time 2.5 mg, 1 time per day) and must closely monitor blood pressure during treatment. dosage adjustment.

4. Taking more than 10 mg may increase the antihypertensive effect, but at the same time increase the incidence of side effects such as edema and arterial tension. Patients with impaired renal function generally do not require a dose adjustment.

5. This drug is used on an empty stomach or after a light meal. The drug should be swallowed whole. Do not chew or break the tablet. Maintaining good oral hygiene can fight gingivitis or reduce gingivitis.

Overdose

Symptom

Overdosage of felodipine resulted in symptoms of peripheral vasodilatation with peripheral edema, severe hypotension, and bradycardia.

To solve

If hypotension is severe, supportive and symptomatic measures should be instituted promptly. Place the patient in supine position, elevate the legs, and administer intravenous fluids. When bradycardia can be used in combination with atropine (0.5-1 mg, slowly injected into the vein).

Contraindications

Hypersensitivity to felodipine and its components.

Pregnant and lactating women.

Use in pregnant and lactating women

There are currently no adequate and well-controlled studies on the use of the drug in pregnant women, but animal experiments have shown adverse effects, so it is recommended that women of childbearing age, This product can be teratogenic, affect delivery and make the breasts dangerously large. It is not clear whether this drug is mixed in breast milk, but this product can cause unwanted reactions in children, so it is recommended to discontinue breastfeeding if the mother drug use.

Interactive

1. When used in combination with felodipine and beta-blockers, it is very effective to avoid drug resistance, but there are reports that when used in combination with metoprolol, it can cause the area under the curve (AUC) of metoprolol and the maximum concentration of metoprolol. Cmax increased to 31% and 38% respectively.

2. Co-administration with cimetidine may increase the area under the curve (AUC) of felodipine and maximum Cmax by 50%. Therefore, when used in combination with cimetidine, the dose of felodipine must be adjusted.

3. Concomitant use of felodipine with digoxin has not been found to cause significant changes in the pharmacokinetics of digoxin in patients with heart failure.

4. The antiepileptic drugs phenytoin, carbamazepine or phenobarbital can reduce the maximum plasma concentration of felodipine in patients with epilepsy, the AUC decreases by 6%, so it is necessary to adjust the method. therapy for these patients.

5. Other drugs such as indometacin or spironolactone do not have significant interactions with felodipine.

Adverse Effects (ADRs)

1. This product is like other calcium blockers, for some patients there may be reactions such as hot flushing, headache, dizziness, heart palpitations and fatigue, the cause of These reactions are mainly due to dose dependence, moreover, they begin to appear shortly after increasing the dose, but only temporary, with long-term use these reactions will disappear.

2. This product, like other dihydropyridines, can cause swelling of the ankles, gingivitis and root canals due to dose-related, patients after using the drug may slightly swollen gums.

3. In addition, there may also be itching and a rash.

4. A small number of patients may have a hypotensive reaction accompanied by marked tachycardia, in hypersensitive patients there may be myocardial hypoxia.

Preservation

At temperatures below 30oC, in a dry place and protected from light.

Presentation and packaging

Controlled release tablets: box of 1 blister x 10 tablets, 2 blisters x 10 tablets, 3 blisters x 10 tablets.