Usage
- Efonidipine + Metoprolol Succinate is prescribed for the management of hypertension (high blood pressure).
- Pharmacological Classification:
- Efonidipine: Dihydropyridine Calcium Channel Blocker
- Metoprolol Succinate: Beta-1 selective adrenergic receptor blocker
- Mechanism of Action: Efonidipine blocks both L-type and T-type calcium channels, leading to vasodilation. Metoprolol succinate blocks beta-1 receptors in the heart, decreasing heart rate and contractility. The combined effect lowers blood pressure.
Alternate Names
- Efonidipine Hydrochloride Ethanolate + S(-) Metoprolol Succinate
- Brand Name: EFNOCAR-MX
How It Works
- Pharmacodynamics: Efonidipine inhibits calcium influx into vascular smooth muscle cells, causing vasodilation and reducing peripheral vascular resistance. Metoprolol selectively blocks beta-1 adrenergic receptors in the heart, reducing heart rate and contractility, thereby decreasing cardiac output.
- Pharmacokinetics:
- Efonidipine: Absorbed orally, metabolized in the liver primarily via CYP3A4. It has a bioavailability of ~25% and a half-life of ~4 hours.
- Metoprolol: Absorbed orally, reaching peak plasma concentration in 1.5-2 hours. Metabolized primarily by CYP2D6. The half-life is 3-7 hours. Less than 5% is excreted unchanged in the urine.
- Elimination: Both drugs are primarily metabolized in the liver, and their metabolites are excreted mainly through the kidneys.
Dosage
Standard Dosage
Adults:
- Initial dose: One tablet of Efonidipine 40 mg + Metoprolol Succinate 25 mg once daily.
- The dose may be increased to a maximum of two tablets per day, depending on blood pressure response.
Children:
- The safety and efficacy have not been established in children and adolescents under 18 years of age. It is not recommended for pediatric use.
Special Cases:
- Elderly Patients: Initiate therapy with caution and monitor closely for adverse effects. Dose adjustments may be necessary.
- Patients with Renal Impairment: Exercise caution in patients with severe renal impairment. Close monitoring of renal function is recommended. Dose adjustment might be required.
- Patients with Hepatic Dysfunction: Use cautiously in patients with liver impairment. Dosage adjustments may be required.
- Patients with Comorbid Conditions: Closely monitor patients with asthma, bronchitis, diabetes, or other cardiovascular conditions, as this medication can exacerbate these conditions.
Clinical Use Cases
Dosage recommendations for specific clinical use cases, such as intubation, surgical procedures, mechanical ventilation, ICU use, and emergency situations, have not been specifically established for this combination. Dosage should be individualized based on the patient’s blood pressure response and overall clinical condition.
Dosage Adjustments
Dose adjustments may be necessary for patients with renal or hepatic impairment, metabolic disorders, or those exhibiting potential drug interactions. Close monitoring and titration are crucial.
Side Effects
Common Side Effects
- Dizziness
- Headache
- Fatigue
- Peripheral edema (swelling in the feet or ankles)
- Flushing
Rare but Serious Side Effects
- Bradycardia (slow heart rate)
- Hypotension (low blood pressure), potentially leading to syncope (fainting)
- Worsening of pre-existing heart conditions
- Bronchospasm in patients with asthma or bronchitis
Long-Term Effects
Chronic complications from prolonged use have not been extensively studied but may include worsening of underlying cardiovascular diseases if blood pressure is not adequately controlled.
Adverse Drug Reactions (ADR)
Clinically significant ADRs that necessitate immediate intervention include severe hypotension, bradycardia, and bronchospasm.
Contraindications
- Hypersensitivity to efonidipine, metoprolol, or any components of the formulation.
- Severe bradycardia or atrioventricular block
- Sick sinus syndrome
- Cardiogenic shock
- Decompensated heart failure
- Severe hepatic impairment
Drug Interactions
- Other antihypertensives (additive effect)
- CYP3A4 inhibitors or inducers (may affect efonidipine metabolism)
- CYP2D6 inhibitors (may affect metoprolol metabolism)
- Cimetidine (increases blood concentration of efonidipine)
- Grapefruit juice (increases blood levels of efonidipine)
Pregnancy and Breastfeeding
Efonidipine + Metoprolol Succinate is generally contraindicated during pregnancy and breastfeeding due to potential risks to the fetus or neonate. Metoprolol can cross the placenta and is excreted in breast milk. Consult a physician for alternative safer options.
Drug Profile Summary
- Mechanism of Action: Efonidipine: Calcium channel blocker causing vasodilation. Metoprolol: Beta-blocker reducing heart rate and contractility.
- Side Effects: Dizziness, headache, fatigue, peripheral edema, flushing, bradycardia, hypotension.
- Contraindications: Hypersensitivity, severe bradycardia or heart block, cardiogenic shock, decompensated heart failure, severe hepatic impairment.
- Drug Interactions: Other antihypertensives, CYP3A4/2D6 inhibitors/inducers, cimetidine, grapefruit juice.
- Pregnancy & Breastfeeding: Contraindicated.
- Dosage: Adults: Initially one tablet daily, may increase to two. Children: Not recommended.
- Monitoring Parameters: Blood pressure, heart rate, ECG.
Precautions
- General Precautions: Pre-screening for allergies, metabolic disorders, and organ dysfunction.
- Specific Populations:
- Pregnant Women: Contraindicated due to risks to the fetus.
- Breastfeeding Mothers: Contraindicated due to the risk of neonatal exposure through breast milk.
- Children & Elderly: Not recommended for children. Use with caution in the elderly.
- Lifestyle Considerations: Avoid alcohol as it may worsen side effects like dizziness and increase blood pressure. Avoid driving or operating machinery until you know how this medication affects you, as it may cause dizziness or drowsiness.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Efonidipine + Metoprolol Succinate?
A: The standard starting dose for adults is one tablet of Efonidipine 40 mg + Metoprolol Succinate 25 mg once daily. Depending on blood pressure response, the dose may be increased to a maximum of two tablets per day. It is not recommended for children.
Q2: What are the common side effects?
A: Common side effects include dizziness, headache, fatigue, peripheral edema, and flushing.
Q3: What are the serious side effects?
A: Serious side effects may include bradycardia, hypotension, worsening of pre-existing heart conditions, and bronchospasm. Seek immediate medical attention if these occur.
Q4: Can this medication be used during pregnancy or breastfeeding?
A: No, Efonidipine + Metoprolol Succinate is contraindicated during pregnancy and breastfeeding due to potential risks to the fetus or neonate.
Q5: What other medications should be avoided while taking this drug?
A: Avoid other antihypertensives, CYP3A4/2D6 inhibitors or inducers, cimetidine, and grapefruit juice. Consult your doctor about all medications you are taking, including OTC drugs and supplements.
Q6: What should patients with liver or kidney problems do?
A: Patients with liver or kidney problems should use this medication with caution. Inform your doctor about any pre-existing conditions, as dose adjustments may be necessary.
Q7: What are the key monitoring parameters for this drug?
A: Blood pressure, heart rate, and ECG should be monitored regularly.
Q8: Can I stop taking this medication once my blood pressure is controlled?
A: No, do not stop taking this medication abruptly without consulting your doctor. Sudden discontinuation can lead to a rise in blood pressure.
Q9: What if I miss a dose?
A: If you miss a dose, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
Q10: How should this medication be stored?
A: Store Efonidipine + Metoprolol Succinate in a cool, dry place away from sunlight.
