Usage
- Cilnidipine is primarily prescribed for the treatment of hypertension (high blood pressure). It’s also reported to be useful in elderly patients and those with diabetes and albuminuria. It has seen increasing use in patients with chronic kidney disease.
- Pharmacological Classification: Dihydropyridine Calcium Channel Blocker.
- Mechanism of Action: Cilnidipine blocks L-type calcium channels in vascular smooth muscle, leading to vasodilation and reduced blood pressure. It also blocks N-type calcium channels, which may contribute to suppressing sympathetic nervous system activity and further lowering blood pressure.
Alternate Names
Cilnidipine is the generic name. Brand names vary depending on the region and manufacturer. Some examples include: Cilacar, Cinod, Abelec, and others. Always consult regional resources for locally available brand names.
How It Works
- Pharmacodynamics: Cilnidipine primarily affects the vascular smooth muscle by blocking calcium influx through L-type calcium channels. This results in vasodilation, lowering peripheral vascular resistance and blood pressure. It also has some inhibitory effects on N-type calcium channels in sympathetic nerves, which may contribute to a reduction in sympathetic tone and heart rate.
- Pharmacokinetics: Cilnidipine is administered orally and is well-absorbed. It achieves peak plasma concentrations within a few hours. It’s extensively metabolized in the liver, primarily by CYP3A4 enzymes. Elimination occurs mainly through the biliary route with a smaller portion via renal excretion.
- Mode of Action: At the cellular level, cilnidipine binds to specific sites on the L-type and N-type calcium channels, preventing the influx of calcium ions into the cells. This inhibits smooth muscle contraction in blood vessels and reduces norepinephrine release from sympathetic nerves.
- Receptor Binding/Enzyme Inhibition: Cilnidipine specifically binds to and inhibits L-type and N-type voltage-gated calcium channels.
- Elimination Pathways: Primarily hepatic metabolism (CYP3A4) followed by biliary excretion; partial renal excretion.
Dosage
Standard Dosage
Adults:
The initial dose is typically 5-10 mg once daily, taken orally. This may be increased to a maximum of 20 mg once daily if needed.
Children:
The safety and efficacy of cilnidipine in children have not been established, so it is generally not recommended for pediatric use.
Special Cases:
- Elderly Patients: Begin with a lower dose (e.g., 5 mg) due to increased sensitivity to hypotension.
- Patients with Renal Impairment: Dose adjustments may be necessary, though studies suggest cilnidipine can be used in patients with mild to moderate renal impairment with careful monitoring.
- Patients with Hepatic Dysfunction: Use with caution and consider starting with a lower dose.
- Patients with Comorbid Conditions: Cilnidipine may be beneficial in patients with diabetes and albuminuria.
Clinical Use Cases
The primary clinical use case is the management of hypertension. Dosing for specific medical settings like intubation, surgery, mechanical ventilation, ICU use, or emergency situations is not specifically indicated. Cilnidipine is not commonly used in these acute settings. Other agents are preferred.
Dosage Adjustments
Dosage adjustments may be necessary based on patient-specific factors, including renal or hepatic dysfunction, and the presence of other medical conditions. Individualized dosing should be based on the patient’s response to therapy.
Side Effects
Common Side Effects
Headache, dizziness, flushing, peripheral edema (swelling of ankles and feet), palpitations, and gastrointestinal disturbances.
Rare but Serious Side Effects
Hypotension (low blood pressure), angina (chest pain), myocardial infarction (heart attack), and allergic reactions.
Long-Term Effects
Limited information is available on long-term effects, but chronic use may require monitoring for liver and kidney function.
Adverse Drug Reactions (ADR)
Clinically significant ADRs include severe hypotension, angina, and allergic reactions, which warrant immediate medical attention.
Contraindications
Hypersensitivity to cilnidipine, cardiogenic shock, severe aortic stenosis, recent myocardial infarction, unstable angina, severe heart failure, and hypotension. It is also contraindicated during the second and third trimesters of pregnancy.
Drug Interactions
Cilnidipine can interact with other antihypertensive medications, grapefruit juice, and drugs metabolized by CYP3A4, such as certain antifungals (ketoconazole, itraconazole), macrolide antibiotics (erythromycin), and some antivirals. Concomitant use of these agents may require dose adjustments.
Pregnancy and Breastfeeding
- Cilnidipine is contraindicated during the second and third trimesters of pregnancy due to potential risks to the fetus. Use during the first trimester should only be considered if the benefits outweigh the potential risks.
- It is not known whether cilnidipine is excreted in breast milk. Caution should be exercised when administered to nursing mothers.
Drug Profile Summary
- Mechanism of Action: Dihydropyridine calcium channel blocker, primarily acting on L-type and also N-type channels, resulting in vasodilation.
- Side Effects: Headache, dizziness, flushing, peripheral edema, palpitations, gastrointestinal disturbances. Rarely: Hypotension, angina, myocardial infarction.
- Contraindications: Hypersensitivity, cardiogenic shock, severe aortic stenosis, recent MI, unstable angina, severe heart failure, hypotension, second and third trimesters of pregnancy.
- Drug Interactions: Other antihypertensives, CYP3A4 inhibitors and inducers, grapefruit juice.
- Pregnancy & Breastfeeding: Contraindicated in second and third trimesters. Caution during breastfeeding.
- Dosage: 5-10 mg once daily, up to 20 mg maximum.
- Monitoring Parameters: Blood pressure, heart rate, signs of peripheral edema, liver and kidney function (with chronic use).
Popular Combinations
Cilnidipine is often combined with other antihypertensive agents, such as telmisartan, chlorthalidone, or olmesartan, particularly for patients with resistant hypertension or comorbid conditions.
Precautions
- General Precautions: Assess for allergies, hepatic and renal function, cardiac function, and other medical conditions before starting therapy.
- Pregnant Women: Avoid use, especially in the second and third trimesters.
- Breastfeeding Mothers: Exercise caution.
- Children & Elderly: Not recommended for children. Start elderly patients with a lower dose and monitor closely.
FAQs
Q1: What is the recommended dosage for Cilnidipine?
A: Adults: Initial 5-10 mg once daily, maximum 20 mg daily. Children: Not recommended. Elderly: Start with 5 mg and adjust cautiously.
Q2: How does Cilnidipine differ from other calcium channel blockers?
A: Cilnidipine blocks both L- and N-type calcium channels, potentially offering additional benefits in terms of sympathetic nervous system suppression and heart rate control compared to some other calcium channel blockers that primarily block L-type channels.
Q3: Can Cilnidipine be used in patients with renal impairment?
A: Use with caution in patients with renal impairment. While studies suggest some efficacy and tolerability in mild to moderate renal dysfunction, careful monitoring is essential.
Q4: What are the most serious side effects of Cilnidipine?
A: Severe hypotension, angina, myocardial infarction, and allergic reactions. Seek immediate medical attention if these occur.
Q5: Are there any specific dietary restrictions while taking Cilnidipine?
A: Grapefruit juice should be avoided as it can interact with Cilnidipine and increase its blood levels. A low-sodium diet is generally recommended for hypertension management.
Q6: Can Cilnidipine be abruptly discontinued?
A: No, abrupt discontinuation can exacerbate angina. Dosage should be gradually tapered down under medical supervision.
Q7: What should patients be counseled on while taking Cilnidipine?
A: Inform patients about potential side effects like dizziness and edema. Emphasize the importance of adherence to medication and lifestyle modifications (diet, exercise). Advise against driving or operating machinery if dizziness occurs. Caution against abrupt discontinuation.
Q8: Is Cilnidipine safe during pregnancy?
A: Cilnidipine is contraindicated during the second and third trimesters of pregnancy. Use in the first trimester should be considered only if the benefits clearly outweigh the risks.
Q9: Can Cilnidipine be used with other antihypertensive drugs?
A: Yes, Cilnidipine can be used in combination with other antihypertensive agents to achieve better blood pressure control. However, be mindful of potential additive hypotensive effects. Dose adjustments may be necessary.
