Usage
- Benidipine + Telmisartan is prescribed for the management of hypertension (high blood pressure). It is also indicated for cardiovascular risk reduction in patients over 55 years of age who are unable to tolerate ACE inhibitors.
- Pharmacological Classification: Antihypertensive (combination of a calcium channel blocker and an angiotensin II receptor blocker).
- Mechanism of Action: Benidipine, a dihydropyridine calcium channel blocker, inhibits calcium influx into vascular smooth muscle cells, leading to vasodilation. Telmisartan, an angiotensin II receptor blocker (ARB), blocks the binding of angiotensin II to its receptor, thereby inhibiting vasoconstriction and aldosterone secretion. The combined effect results in a synergistic reduction in blood pressure.
Alternate Names
- No widely recognized alternate names exist for the combination. The individual components are sometimes referred to as benidipine hydrochloride and telmisartan.
- Brand Names: Benidin T, Inzit TL, Benibuz TM (and potentially others depending on the region).
How It Works
- Pharmacodynamics: Benidipine lowers blood pressure by decreasing peripheral vascular resistance. Telmisartan blocks the effects of angiotensin II, resulting in vasodilation and reduced aldosterone secretion. This combination targets two different mechanisms related to blood pressure control.
- Pharmacokinetics:
- Absorption: Both drugs are orally absorbed.
- Metabolism: Benidipine is extensively metabolized in the liver, primarily via CYP3A4 enzymes. Telmisartan undergoes minimal hepatic metabolism.
- Elimination: Benidipine is eliminated mainly through the biliary/fecal route, with a small fraction excreted renally. Telmisartan is primarily excreted unchanged in the bile/feces, with less than 1% excreted in urine.
- Mode of Action: Benidipine blocks L-type calcium channels in vascular smooth muscle, preventing calcium influx and subsequent contraction. Telmisartan selectively binds to the AT1 subtype of angiotensin II receptors, inhibiting the vasoconstricting and aldosterone-secreting effects of angiotensin II.
Dosage
Standard Dosage
Adults:
- Initial dose: Benidipine 4 mg + Telmisartan 40 mg once daily.
- Maintenance dose: Can be increased up to Benidipine 8 mg + Telmisartan 80 mg once daily as needed to control blood pressure.
Children:
- Not recommended for use in children under 18 years of age. Safety and efficacy have not been established.
Special Cases:
- Elderly Patients: Initiate therapy at a lower dose (e.g., Benidipine 2 mg + Telmisartan 20 mg) and titrate cautiously.
- Patients with Renal Impairment: Use with caution. Closely monitor renal function and electrolytes. A lower starting dose may be considered, particularly in patients with severe renal impairment or those on hemodialysis.
- Patients with Hepatic Dysfunction: Start with a low dose and titrate slowly due to potential alterations in pharmacokinetics, especially in severe hepatic impairment or biliary obstructive disorders.
- Patients with Comorbid Conditions: Use cautiously in patients with diabetes, heart failure, or other cardiovascular conditions. Monitor blood pressure and electrolyte levels regularly.
Clinical Use Cases
- This medication is primarily used in the chronic management of hypertension. It is not typically administered in situations like intubation, surgical procedures, mechanical ventilation, ICU use, or emergency scenarios.
Dosage Adjustments
- Adjust dosage based on blood pressure response, renal function, hepatic function, and concomitant medications.
Side Effects
Common Side Effects
- Headache
- Dizziness
- Fatigue
- Peripheral edema
- Back pain
- Nausea
- Diarrhea
Rare but Serious Side Effects
- Hypotension (low blood pressure)
- Angioedema (swelling of the face, lips, tongue, or throat)
- Renal dysfunction
- Hyperkalemia (high potassium levels)
- Hepatic dysfunction
Long-Term Effects
- The long-term effects of this combination therapy primarily relate to improved cardiovascular outcomes associated with better blood pressure control, such as reduced risk of stroke and heart attack. Regular monitoring of blood pressure, renal function, and electrolyte levels is important.
Adverse Drug Reactions (ADR)
- Angioedema, severe hypotension, acute renal failure, and hyperkalemia are serious ADRs that require immediate medical attention.
Contraindications
- Hypersensitivity to benidipine, telmisartan, or any component of the formulation
- Severe hepatic impairment or biliary obstructive disorders
- Anuria (inability to produce urine)
- Pregnancy (especially second and third trimesters)
- Concomitant use of aliskiren in patients with diabetes
Drug Interactions
- Diuretics (e.g., furosemide, hydrochlorothiazide): May enhance hypotensive effects.
- Potassium supplements or potassium-sparing diuretics (e.g., spironolactone, triamterene): Can increase the risk of hyperkalemia.
- Lithium: Co-administration can increase lithium toxicity.
- NSAIDs (e.g., ibuprofen, naproxen): May reduce the antihypertensive effect.
- CYP3A4 inhibitors (e.g., ketoconazole, ritonavir): May increase benidipine levels.
- Digoxin: Monitor for potential digoxin toxicity.
- Alcohol: May potentiate the hypotensive effect.
- Grapefruit juice: May increase benidipine levels.
Pregnancy and Breastfeeding
- Pregnancy Safety Category: D (according to older FDA classification). Not recommended during pregnancy, especially in the second and third trimesters, due to potential harm to the fetus (risk of fetal renal toxicity and growth retardation).
- Breastfeeding: It is unknown if benidipine or telmisartan are excreted in breast milk. Use with caution. Consider the benefits versus risks or choose alternative medications.
Drug Profile Summary
- Mechanism of Action: Calcium channel blockade (benidipine) and angiotensin II receptor blockade (telmisartan).
- Side Effects: Headache, dizziness, fatigue, peripheral edema, back pain, nausea, diarrhea. Rarely: hypotension, angioedema, renal dysfunction, hyperkalemia.
- Contraindications: Hypersensitivity, severe hepatic impairment, biliary obstructive disorders, anuria, pregnancy, concurrent use of aliskiren in diabetics.
- Drug Interactions: Diuretics, potassium supplements, lithium, NSAIDs, CYP3A4 inhibitors, digoxin, alcohol, grapefruit juice.
- Pregnancy & Breastfeeding: Not recommended during pregnancy. Use with caution during breastfeeding.
- Dosage: Adults: 4/40 mg to 8/80 mg once daily. Adjust based on response and patient factors. Not recommended for children.
- Monitoring Parameters: Blood pressure, renal function (BUN, creatinine, electrolytes), liver function tests.
Popular Combinations
- While this medication itself is a combination, the addition of a thiazide diuretic (like hydrochlorothiazide or chlorthalidone) is sometimes used in clinical practice to further enhance blood pressure control in patients whose blood pressure is not adequately managed with the dual combination alone.
Precautions
- General Precautions: Monitor blood pressure, renal function, and electrolyte levels regularly. Assess for history of hypersensitivity, hepatic dysfunction, or renal impairment.
- Specific Populations: See “Dosage - Special Cases” above.
- Lifestyle Considerations: Encourage lifestyle modifications such as dietary changes (low sodium, low fat), regular exercise, weight management, smoking cessation, and limiting alcohol intake. Caution patients about potential dizziness and advise against driving or operating machinery until the effects of the medication are known.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Benidipine + Telmisartan?
A: The initial recommended dose is Benidipine 4 mg + Telmisartan 40 mg once daily. This can be titrated up to a maximum of Benidipine 8 mg + Telmisartan 80 mg once daily as needed to control blood pressure. Elderly patients and those with hepatic or renal dysfunction may require lower starting doses.
Q2: How does this combination medication work to lower blood pressure?
A: It utilizes two different mechanisms: calcium channel blockade (benidipine) to relax blood vessels and angiotensin II receptor blockade (telmisartan) to prevent vasoconstriction and reduce aldosterone secretion.
Q3: What are the most common side effects?
A: The most common side effects are headache, dizziness, fatigue, peripheral edema, back pain, nausea, and diarrhea.
Q4: Are there any serious side effects I should be aware of?
A: Yes. While rare, serious side effects such as hypotension, angioedema, renal dysfunction, and hyperkalemia can occur. Patients should seek immediate medical attention if they experience these.
Q5: Can pregnant women take this medication?
A: No. This medication is contraindicated during pregnancy, particularly in the second and third trimesters, due to the risk of fetal harm.
Q6: What should I do if I miss a dose?
A: Take the missed dose as soon as you remember. However, if it is almost time for the next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one.
Q7: What other medications should be avoided when taking Benidipine + Telmisartan?
A: Avoid or use cautiously with other antihypertensives, potassium supplements, potassium-sparing diuretics, lithium, NSAIDs, CYP3A4 inhibitors, digoxin, alcohol, and grapefruit juice. Consult with a physician about potential drug interactions.
Q8: What are the key monitoring parameters for patients on this medication?
A: Regularly monitor blood pressure, renal function (BUN, creatinine, electrolytes), and liver function tests.
Q9: Is this combination more effective than taking either drug alone?
A: The combination of Benidipine and Telmisartan can provide better blood pressure control compared to using either drug alone because they target two different mechanisms involved in regulating blood pressure.
Q10: What precautions should be taken for patients with renal or hepatic impairment?
A: Start with a lower dose and titrate cautiously, monitoring renal and liver function closely. In severe renal or hepatic impairment, the use of this medication might require careful consideration.
