Usage
- S-Amlodipine + Telmisartan is prescribed for the treatment of hypertension (high blood pressure). It is used when a single medication is not enough to control blood pressure. This combination may also indirectly reduce the risk of heart attacks and strokes in individuals at risk.
- Pharmacological Classification: Antihypertensive (a combination of a calcium channel blocker and an angiotensin II receptor blocker).
- Mechanism of Action: This combination medication works by two distinct mechanisms. S-Amlodipine, a calcium channel blocker, widens blood vessels by relaxing their smooth muscles, which eases blood flow. Telmisartan, an angiotensin II receptor blocker (ARB), prevents the hormone angiotensin II from constricting blood vessels. Together, these actions lower blood pressure.
Alternate Names
- This combination is often referred to as the S-Amlodipine + Telmisartan fixed-dose combination (FDC).
- Brand Names: Several brands market this combination, such as Twynsta and Numlo TM. Regional variations in brand names may exist.
How It Works
- Pharmacodynamics: S-Amlodipine primarily affects the vascular smooth muscle and cardiac muscle by blocking calcium influx, thus reducing vascular tone. Telmisartan blocks the action of angiotensin II at its receptor sites, preventing vasoconstriction and aldosterone release.
- Pharmacokinetics:
- Absorption: Both drugs are orally absorbed. Telmisartan shows an absolute bioavailability of approximately 50%, while S-amlodipine’s bioavailability is around 60-65%. Food intake does not significantly affect either drug’s absorption.
- Metabolism: Telmisartan undergoes minimal metabolism, while S-Amlodipine is extensively metabolized by the liver, primarily by CYP3A4 enzymes.
- Elimination: Telmisartan is primarily eliminated via biliary excretion in feces, whereas S-Amlodipine is mostly excreted in urine and feces as metabolites, with a longer half-life than Telmisartan.
- Mode of Action: S-Amlodipine blocks the influx of calcium ions into vascular and cardiac muscle cells. Telmisartan blocks angiotensin II at the AT1 receptor, thus preventing vasoconstriction, reducing aldosterone secretion, and lowering blood pressure.
- Receptor Binding/Enzyme Inhibition: S-Amlodipine acts on L-type calcium channels. Telmisartan competitively binds to the AT1 receptor.
- Elimination Pathways: Telmisartan is primarily excreted unchanged in bile. S-Amlodipine is extensively metabolized by hepatic CYP3A4 enzymes, and metabolites are excreted in urine and feces.
Dosage
Standard Dosage
Adults:
- Initial dose: S-Amlodipine 2.5 mg + Telmisartan 40 mg once daily.
- Maintenance dose: The dose may be increased to a maximum of S-Amlodipine 5 mg + Telmisartan 80 mg once daily, as needed and tolerated.
Children:
- Not recommended for patients under 18 years of age. Safety and effectiveness in pediatric patients have not been established.
Special Cases:
- Elderly Patients (over 75 years): Initial therapy with this combination is not recommended. If used, start with a low dose of S-Amlodipine and titrate slowly.
- Patients with Renal Impairment: Mild to moderate impairment: no adjustment needed. Severe impairment: titrate slowly with close monitoring.
- Patients with Hepatic Dysfunction: Not recommended for initial therapy. In cases of biliary obstructive disorders, initiate therapy with a low dose and titrate cautiously.
- Patients with Comorbid Conditions: Caution is advised in patients with diabetes, heart failure, or severe obstructive coronary artery disease.
Clinical Use Cases
The specific use cases you mentioned (intubation, surgical procedures, mechanical ventilation, ICU use, emergency situations) are not standard indications for this medication. S-Amlodipine + Telmisartan is primarily used for chronic hypertension management.
Dosage Adjustments
- Adjust dosages based on individual patient response and tolerability.
- Renal and hepatic impairment may necessitate dosage reductions.
Side Effects
Common Side Effects
- Dizziness, headache, swelling in hands, feet, and ankles (edema), fatigue, nausea, flushing (warmth and redness of the face and neck), sleepiness, stomach pain, diarrhea.
Rare but Serious Side Effects
- Severe hypotension (low blood pressure), allergic reactions (angioedema), abnormal heart rhythms, kidney problems.
Long-Term Effects
- Long-term use can potentially cause persistent peripheral edema and electrolyte imbalances. Monitoring of potassium and creatinine levels is important in patients with impaired renal function.
Adverse Drug Reactions (ADR)
- Severe hypotension, angioedema, acute renal failure, hyperkalemia, hepatotoxicity.
Contraindications
- Hypersensitivity to S-Amlodipine, Telmisartan, or any component of the medication.
- Pregnancy (especially second and third trimesters).
- Breastfeeding.
- Severe hepatic impairment.
- Biliary obstructive disorders.
- Concurrent use with aliskiren in patients with diabetes.
Drug Interactions
- Other antihypertensives (may potentiate hypotension).
- CYP3A4 inhibitors (ketoconazole, itraconazole) and inducers (rifampicin) may alter S-Amlodipine levels.
- NSAIDs (ibuprofen, naproxen) may reduce antihypertensive effect and increase the risk of renal impairment.
- Lithium (increased lithium toxicity).
- Digoxin (increased digoxin levels).
- Grapefruit juice (may increase S-Amlodipine levels).
- Potassium supplements (may cause hyperkalemia).
- Alcohol (may increase the risk of hypotension).
Pregnancy and Breastfeeding
- Pregnancy Safety Category: D (Australia); Not assigned (US FDA, as categories are being phased out). Contraindicated during pregnancy, especially the second and third trimesters, due to the risk of fetal harm.
- Fetal risks include fetotoxicity, intrauterine death, and neonatal morbidity.
- Not recommended during breastfeeding as S-Amlodipine is known to be excreted in breast milk, and the effects of Telmisartan on infants are unknown.
Drug Profile Summary
- Mechanism of Action: S-Amlodipine: calcium channel blocker; Telmisartan: angiotensin II receptor blocker.
- Side Effects: Dizziness, headache, edema, fatigue, nausea.
- Contraindications: Hypersensitivity, pregnancy, breastfeeding, severe hepatic impairment, biliary obstructive disorders.
- Drug Interactions: Other antihypertensives, CYP3A4 inhibitors/inducers, NSAIDs, lithium, digoxin, grapefruit juice, alcohol.
- Pregnancy & Breastfeeding: Contraindicated.
- Dosage: Adults: 2.5/40 mg to 5/80 mg once daily. Not recommended for children.
- Monitoring Parameters: Blood pressure, potassium levels, creatinine levels (especially in patients with renal impairment), signs of edema, liver function tests.
Popular Combinations
While S-Amlodipine + Telmisartan is itself a combination, it may be prescribed alongside other antihypertensives like diuretics (hydrochlorothiazide) or beta-blockers (metoprolol) if blood pressure control remains inadequate. The rationale for this is synergistic blood pressure reduction through different mechanisms. However, such combinations should be carefully monitored for potential additive adverse effects.
Precautions
- General Precautions: Monitor for allergic reactions, edema, and electrolyte imbalances.
- Specific Populations: Avoid use in pregnant and breastfeeding women. Exercise caution in patients with pre-existing heart, liver, or kidney conditions, as well as the elderly.
- Lifestyle Considerations: Reduce salt intake, limit alcohol consumption, and be cautious when driving or operating machinery due to potential dizziness.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for S-Amlodipine + Telmisartan?
A: The starting dose is usually S-Amlodipine 2.5 mg + Telmisartan 40 mg once daily. The dose can be increased to a maximum of S-Amlodipine 5 mg + Telmisartan 80 mg once daily, based on individual patient response and tolerability. It is crucial to consider patient-specific factors like age, renal function, and hepatic function when adjusting dosage.
Q2: What are the common side effects of this medication?
A: Common side effects include dizziness, headache, peripheral edema (swelling in the ankles and feet), fatigue, and nausea.
Q3: Is S-Amlodipine + Telmisartan safe during pregnancy?
A: No. This medication is contraindicated during pregnancy, particularly in the second and third trimesters, due to the risk of fetal harm and neonatal complications. Alternative antihypertensives should be considered for pregnant women.
Q4: How does this combination medication interact with grapefruit juice?
A: Grapefruit juice can inhibit CYP3A4 enzymes, which metabolize S-Amlodipine. This can lead to elevated S-Amlodipine levels and an increased risk of side effects like hypotension. Patients should avoid consuming grapefruit juice while taking S-Amlodipine + Telmisartan.
Q5: Can patients with renal impairment take this medicine?
A: Patients with mild to moderate renal impairment can generally take this medication without dose adjustment, but close monitoring of renal function is necessary. In patients with severe renal impairment, the dose should be titrated cautiously and slowly.
Q6: What should a patient do if they miss a dose?
A: If a dose is missed, take it as soon as remembered unless it’s close to the next scheduled dose. In that case, skip the missed dose and take the next dose at the regular time. Do not double the dose to catch up.
Q7: Can S-Amlodipine + Telmisartan be used in children?
A: No. The safety and efficacy of this medication in children below 18 years have not been established, and it’s therefore not recommended for pediatric use.
Q8: Are there any specific dietary recommendations while taking this medication?
A: Patients are advised to reduce their sodium (salt) intake to help control blood pressure. Additionally, limiting alcohol consumption is recommended, as it can exacerbate side effects like hypotension.
Q9: What are the signs of an overdose?
A: An overdose may manifest as severe hypotension, dizziness, fainting, and changes in heart rate (bradycardia or tachycardia). Seek immediate medical attention if an overdose is suspected.
