Usage
- Atenolol + S-Amlodipine is primarily prescribed for the treatment of hypertension (high blood pressure). It may also be used to prevent angina (chest pain) and improve survival rates after a heart attack.
- Pharmacological Classification: This combination drug falls under two classifications:
- Atenolol: Beta-blocker (Cardio-selective)
- S-Amlodipine: Calcium channel blocker (Dihydropyridine type)
- Mechanism of Action: Atenolol works by blocking beta-1 adrenergic receptors in the heart, reducing heart rate and cardiac output. S-Amlodipine blocks calcium channels in vascular smooth muscle and cardiac muscle, leading to vasodilation and decreased myocardial contractility. The combined effect lowers blood pressure synergistically.
Alternate Names
- While no official alternate generic names exist, the drug may be referred to as Atenolol/Amlodipine or Amlodipine/Atenolol. Regional or international variations in spelling (e.g., Atenolol vs. Atenolol) might occur but refer to the same drug.
- Brand Names: Several brand names exist depending on the manufacturer and region. Some examples include StayHappi S-Amlodipine+Atenolol and S-Amlosafe AT. The specific brand names available will vary by country.
How It Works
- Pharmacodynamics: Atenolol reduces heart rate, cardiac output, and myocardial contractility. S-Amlodipine reduces peripheral vascular resistance and myocardial oxygen demand. The combination leads to a significant reduction in blood pressure.
- Pharmacokinetics:
- Absorption: Both drugs are orally absorbed.
- Metabolism: Atenolol undergoes minimal hepatic metabolism, with most excreted unchanged in the urine. S-Amlodipine is extensively metabolized by the liver, primarily by CYP3A4.
- Elimination: Atenolol is primarily eliminated through renal excretion. S-Amlodipine is eliminated through both renal and hepatic pathways.
- Mode of Action: Atenolol competitively binds to beta-1 adrenergic receptors, preventing the binding of catecholamines (norepinephrine, epinephrine). S-Amlodipine inhibits the influx of calcium ions into vascular smooth muscle and cardiac muscle cells, preventing contraction and promoting vasodilation.
- Receptor Binding/Enzyme Inhibition/Neurotransmitter Modulation: Atenolol exhibits receptor binding to beta-1 adrenergic receptors. S-Amlodipine targets L-type calcium channels. No direct enzyme inhibition or neurotransmitter modulation is involved.
- Elimination Pathways: Atenolol is primarily excreted unchanged in the urine. S-Amlodipine is extensively metabolized by the liver, predominantly by CYP3A4, with metabolites and some unchanged drug excreted in urine and feces.
Dosage
Standard Dosage
Adults:
- Initial dose: Atenolol 25 mg/S-Amlodipine 2.5 mg or Atenolol 50 mg/S-Amlodipine 5mg once daily.
- The dose may be increased to a maximum of Atenolol 100 mg/S-Amlodipine 10 mg per day, as needed to control blood pressure.
Children:
- Use in children is not well-established. Dosage should be determined by a pediatrician based on the child’s weight, age, and clinical condition.
Special Cases:
- Elderly Patients: Start with a lower dose (Atenolol 25 mg/S-Amlodipine 2.5 mg) and titrate cautiously.
- Patients with Renal Impairment: Adjust the Atenolol dose based on creatinine clearance. Lower doses are generally required.
- Patients with Hepatic Dysfunction: Caution is advised with S-Amlodipine due to its hepatic metabolism. Dosage adjustment may be necessary.
- Patients with Comorbid Conditions: Careful consideration is needed for patients with diabetes, asthma, COPD, peripheral artery disease, thyroid disorders, and other conditions. Dosage adjustments or alternative therapies may be necessary.
Clinical Use Cases
- The combination of Atenolol and S-Amlodipine is not typically used for intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations. Other medications are more appropriate for these scenarios.
Dosage Adjustments
- Dosage adjustments should be made based on patient response, renal function, hepatic function, and concomitant medications. Consider genetic polymorphisms affecting drug metabolism (especially for S-Amlodipine).
Side Effects
Common Side Effects
- Dizziness, lightheadedness, fatigue, headache, nausea, flushing, ankle swelling (edema), bradycardia, palpitations, and cold extremities.
Rare but Serious Side Effects
- Severe hypotension, heart block, worsening heart failure, bronchospasm (in susceptible individuals), and allergic reactions.
Long-Term Effects
- Long-term effects are primarily related to underlying conditions like hypertension, angina, or previous myocardial infarction. The drug combination itself does not usually cause unique long-term side effects.
Adverse Drug Reactions (ADR)
- Serious ADRs include severe hypotension, angioedema, and bronchospasm.
Contraindications
- Hypersensitivity to Atenolol or Amlodipine, severe bradycardia, second- or third-degree heart block, cardiogenic shock, and uncontrolled heart failure.
Drug Interactions
- Other antihypertensives, calcium channel blockers, beta-blockers, digoxin, CYP3A4 inhibitors (e.g., some antifungals, macrolides), and CYP3A4 inducers (e.g., rifampin, phenytoin).
Pregnancy and Breastfeeding
- Use during pregnancy and breastfeeding is generally not recommended due to potential risks to the fetus or infant. Consult with an obstetrician or pediatrician if the benefits outweigh the risks.
Drug Profile Summary
- Mechanism of Action: Atenolol: Beta-1 blocker; S-Amlodipine: Calcium channel blocker.
- Side Effects: Dizziness, fatigue, headache, edema, bradycardia.
- Contraindications: Severe bradycardia, heart block, heart failure.
- Drug Interactions: Other antihypertensives, CYP3A4 inhibitors/inducers.
- Pregnancy & Breastfeeding: Not recommended.
- Dosage: Start with low doses and titrate based on response.
- Monitoring Parameters: Blood pressure, heart rate, renal function, electrolytes.
Popular Combinations
- While Atenolol and S-Amlodipine are themselves a popular combination, other antihypertensives might be added if further blood pressure control is required. These might include thiazide diuretics, ACE inhibitors, or ARBs. However, combining multiple medications increases the risk of side effects and interactions.
Precautions
- General Precautions: Monitor blood pressure, heart rate, and renal function. Caution in patients with diabetes, respiratory conditions, and peripheral artery disease.
- Specific Populations: Adjust dosage in elderly and patients with renal impairment. Avoid use during pregnancy and breastfeeding.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Atenolol + S-Amlodipine?
A: The starting dose is typically Atenolol 25-50 mg and S-Amlodipine 2.5-5 mg once daily, adjusted as needed based on individual response and tolerability.
Q2: Can this combination be used in patients with asthma?
A: Atenolol may exacerbate bronchospasm. Use with caution in patients with asthma or COPD and ensure a bronchodilator is available.
Q3: Are there any significant drug interactions?
A: Yes, this combination can interact with other antihypertensives, calcium channel blockers, beta-blockers, digoxin, and drugs that affect CYP3A4 metabolism.
Q4: Can Atenolol + S-Amlodipine be used in pregnancy?
A: It’s generally not recommended due to potential risks to the fetus.
Q5: What are the common side effects?
A: Common side effects include dizziness, fatigue, headache, edema, bradycardia, and palpitations.
Q6: How does this combination lower blood pressure?
A: Atenolol reduces heart rate and cardiac output, while S-Amlodipine causes vasodilation.
Q7: Should the medication be stopped abruptly?
A: No, abrupt cessation may cause rebound hypertension or angina. Taper the dose gradually under medical supervision.
Q8: What should be monitored during treatment?
A: Blood pressure, heart rate, renal function, and electrolytes. Monitor for symptoms of worsening heart failure or bronchospasm.
Q9: Can this drug be crushed or chewed?
A: It’s best to swallow the tablets whole with water. Consult a pharmacist about specific brands if there are difficulties swallowing.
Q10: Can I consume alcohol while taking this medication?
A: Limit alcohol intake as it can interact with the medication and affect blood pressure.
