Usage
- Amlodipine + Olmesartan Medoxomil is prescribed for the treatment of essential hypertension (high blood pressure). It can be used alone or in conjunction with other antihypertensive medications. This combination therapy is particularly beneficial for patients who may require multiple medications to achieve their target blood pressure goals. It may also be used as a substitute for patients already taking amlodipine and olmesartan separately.
- Pharmacological Classification: This fixed-dose combination medication includes two drug classes:
- Amlodipine: Dihydropyridine Calcium Channel Blocker
- Olmesartan Medoxomil: Angiotensin II Receptor Blocker (ARB)
- Mechanism of Action: Amlodipine works by relaxing the smooth muscles of blood vessels, leading to vasodilation and reduced blood pressure. Olmesartan blocks the action of angiotensin II, a hormone that constricts blood vessels and raises blood pressure. The combined effect results in a more pronounced blood pressure lowering action.
Alternate Names
- While “Amlodipine + Olmesartan Medoxomil” is the generic name, it is often referred to by the components: “Amlodipine and Olmesartan Medoxomil.”
- Brand Name: Azor, Normetec
How It Works
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Pharmacodynamics: The combined action of amlodipine and olmesartan medoxomil results in synergistic blood pressure reduction. Amlodipine, a calcium channel blocker, inhibits calcium influx into vascular smooth muscle, promoting vasodilation. Olmesartan medoxomil, an ARB, blocks the binding of angiotensin II to its receptor, further contributing to vasodilation and preventing the vasoconstricting and aldosterone-secreting effects of angiotensin II.
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Pharmacokinetics: Amlodipine is well absorbed orally and undergoes extensive hepatic metabolism. Olmesartan medoxomil is rapidly hydrolyzed to its active metabolite, olmesartan, during absorption from the gastrointestinal tract. Both drugs are highly protein-bound.
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Mode of Action: At the cellular level, amlodipine targets L-type calcium channels in vascular smooth muscle, preventing calcium entry and reducing muscle contraction. Olmesartan blocks the AT1 receptor, the primary site of angiotensin II action, preventing vasoconstriction.
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Elimination Pathways: Amlodipine is primarily eliminated via hepatic metabolism, with metabolites excreted in urine and feces. Olmesartan is eliminated primarily through biliary excretion and partially through renal excretion.
Dosage
Standard Dosage
Adults:
- Initial dose: 5 mg amlodipine/20 mg olmesartan medoxomil once daily.
- The dose can be increased after 1-2 weeks, as needed, up to a maximum of 10 mg amlodipine/40 mg olmesartan medoxomil once daily.
- Administer orally, with or without food.
Children:
- The safety and efficacy of amlodipine/olmesartan medoxomil have not been established in children younger than 18 years.
Special Cases:
- Elderly Patients: No initial dose adjustment is generally required. However, caution should be exercised during dose titration due to potential age-related decline in renal function.
- Patients with Renal Impairment: No dose adjustment is needed for mild to moderate renal impairment. Use with caution in patients with severe renal impairment (creatinine clearance <20 mL/min).
- Patients with Hepatic Dysfunction: Use with caution in mild to moderate hepatic impairment. In patients with moderate hepatic impairment, start with 10 mg of olmesartan once daily; the maximum dose should not exceed 20 mg once daily. Therapy is not recommended for patients with severe hepatic impairment.
- Patients with Comorbid Conditions: Closely monitor patients with diabetes, heart failure, or aortic stenosis for potential adverse effects such as hypotension, worsening chest pain, or fluid and electrolyte imbalances.
Clinical Use Cases
- The use of amlodipine/olmesartan medoxomil in specific clinical settings like intubation, surgical procedures, mechanical ventilation, ICU use, and emergency situations is not specifically indicated. Individual component drugs might have specific applications in these contexts, but the fixed-dose combination is primarily for chronic hypertension management.
Dosage Adjustments
- Adjust dosages based on individual patient response and tolerability. Consider renal and hepatic function when titrating the dose.
Side Effects
Common Side Effects
- Dizziness, lightheadedness, headache, peripheral edema (swelling in the ankles and feet), fatigue.
Rare but Serious Side Effects
- Hypotension (low blood pressure), syncope (fainting), angioedema (swelling of the face, lips, tongue, or throat), acute renal failure, hyperkalemia (high potassium levels).
Long-Term Effects
- Potential long-term effects could include worsening renal function and electrolyte imbalances with prolonged use. Regular monitoring of renal function and electrolytes is recommended.
Adverse Drug Reactions (ADR)
- Angioedema, severe hypotension, and acute renal failure are serious ADRs requiring immediate medical attention.
Contraindications
- Hypersensitivity to amlodipine, olmesartan medoxomil, or any components of the formulation.
- Pregnancy (especially second and third trimesters).
- Co-administration with aliskiren in patients with diabetes.
- Anuria.
Drug Interactions
- Other antihypertensive medications (additive hypotensive effect).
- Potassium supplements or salt substitutes (increased risk of hyperkalemia).
- NSAIDs (may reduce the antihypertensive effect and increase the risk of renal impairment).
- Lithium (increased risk of lithium toxicity).
- CYP3A4 inhibitors (may increase amlodipine levels).
- CYP3A4 inducers (may decrease amlodipine levels).
Pregnancy and Breastfeeding
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Pregnancy: Contraindicated. Amlodipine/olmesartan can cause fetal harm. Discontinue immediately if pregnancy is detected.
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Breastfeeding: Amlodipine/olmesartan is excreted in breast milk. It is not recommended during breastfeeding.
Drug Profile Summary
- Mechanism of Action: Calcium channel blockade (amlodipine) and angiotensin II receptor blockade (olmesartan medoxomil) leading to vasodilation and reduced blood pressure.
- Side Effects: Dizziness, lightheadedness, peripheral edema, headache, hypotension, angioedema, hyperkalemia.
- Contraindications: Hypersensitivity, pregnancy, co-administration with aliskiren in patients with diabetes.
- Drug Interactions: Other antihypertensives, potassium supplements, NSAIDs, lithium, CYP3A4 inhibitors/inducers.
- Pregnancy & Breastfeeding: Contraindicated in pregnancy; not recommended during breastfeeding.
- Dosage: 5/20 mg once daily, titratable to 10/40 mg once daily.
- Monitoring Parameters: Blood pressure, renal function (serum creatinine, BUN), serum electrolytes (potassium).
Popular Combinations
- A thiazide diuretic may be added for enhanced blood pressure control in some patients who don’t reach their target blood pressure with Amlodipine + Olmesartan Medoxomil alone.
Precautions
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General Precautions: Monitor blood pressure, renal function, and electrolytes regularly. Assess for signs of hypotension and angioedema.
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Specific Populations: Avoid use in pregnancy and breastfeeding. Use with caution in patients with hepatic or renal impairment.
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Lifestyle Considerations: Patients should be advised on lifestyle modifications, including dietary sodium restriction, weight management, and regular exercise.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Amlodipine + Olmesartan Medoxomil?
A: The initial dose is 5 mg amlodipine/20 mg olmesartan medoxomil once daily. It can be increased to a maximum of 10 mg amlodipine/40 mg olmesartan medoxomil once daily, as needed to control blood pressure.
Q2: How should this medication be taken?
A: It should be taken orally once daily, with or without food.
Q3: What are the common side effects?
A: Common side effects include dizziness, lightheadedness, headache, peripheral edema, and fatigue.
Q4: What are the serious side effects I should watch out for?
A: Serious side effects include hypotension, syncope, angioedema, acute renal failure, and hyperkalemia.
Q5: Can pregnant women take this medication?
A: No, this medication is contraindicated in pregnancy, especially during the second and third trimesters.
Q6: Can breastfeeding mothers take this medication?
A: No, this medication is not recommended for breastfeeding mothers as it can be passed to the baby through breast milk.
Q7: What if my patient has renal impairment?
A: Dosage adjustment is not generally required for mild to moderate renal impairment. Exercise caution in severe renal impairment.
Q8: What if my patient has hepatic impairment?
A: Use with caution in mild to moderate hepatic impairment. Dose adjustment may be needed. It is not recommended in severe hepatic impairment.
Q9: What other medications should be avoided while taking this combination?
A: Avoid co-administration with aliskiren in patients with diabetes. Caution should be used with other antihypertensives, potassium supplements, NSAIDs, and lithium.
Q10: What should I monitor in patients taking this medication?
A: Closely monitor blood pressure, renal function (serum creatinine and BUN), and serum electrolytes, especially potassium levels.
