Azelnidipine (Calblock) is a commonly used calcium channel blocker, which is mainly indicated for the treatment of hypertension. It exerts antihypertensive effects by dilating blood vessels and reducing peripheral vascular resistance.

What are the precautions for the administration of Azelnidipine (Calblock)?

Contraindicated populations

(1) Pregnant women or women of childbearing potential.

(2) Patients with a history of hypersensitivity to any component of this medicine.

(3) Patients receiving the following medications: azole antifungal agents (e.g., itraconazole, miconazole, fluconazole); HIV protease inhibitors; and certain compound preparations such as nirmatrelvir/ritonavir. These drugs can significantly inhibit the metabolism of azelnidipine, leading to an abnormal elevation of its plasma concentration and an increased risk of adverse reactions.

Medication in special populations

(1) Elderly patients: Treatment should be initiated at a low dose (e.g., 8 mg), with cautious dose titration to avoid the risk of cerebral ischemia caused by excessive hypotension.

(2) Patients with hepatic or renal insufficiency: Patients with severe renal insufficiency may experience further deterioration of renal function due to decreased blood pressure. There is insufficient research data on patients with severe hepatic insufficiency, so the drug should be administered with extreme caution in this population.

(3) Pediatric patients: Relevant clinical studies are lacking, and the use of this drug is not recommended.

(4) Lactating women: The drug may be excreted in breast milk. A careful weighing of the therapeutic benefits against the risks to breastfeeding infants is required to decide whether to continue lactation.

Important precautions

(1) Abrupt withdrawal is prohibited: Sudden discontinuation of the drug may cause rebound hypertension and exacerbation of symptoms. Dose tapering is required if discontinuation is necessary.

(2) Vigilance against hypotension: Significant hypotension may occur in some patients, and dose reduction or temporary suspension of medication is needed when necessary.

(3) Attention to symptomatic effects: Dizziness, fatigue and other symptoms may occur after administration. Patients should avoid driving, working at heights or operating dangerous machinery.(4) Correct administration method: Tablets should be taken after being removed from the PTP blister pack to avoid esophageal injury caused by accidental ingestion of the pack.

Drug interactions

(1) Contraindicated concomitant medications: As mentioned above, azole antifungal agents and some HIV medications can significantly increase the plasma concentration of azelnidipine, and their combined use is prohibited.

(2) Concomitant medications requiring caution

Other antihypertensive drugs: May potentiate the antihypertensive effect and cause hypotension, necessitating dose adjustment.

Statins (e.g., simvastatin): May increase the plasma concentration of statins and elevate the risk of adverse reactions.

Digoxin: Co-administration may increase the plasma concentration of digoxin, and regular monitoring of digoxin plasma levels is required.

(3) Food interaction: Grapefruit juice can significantly inhibit CYP3A4 activity, resulting in a substantial elevation of azelnidipine plasma concentration. Consumption of grapefruit juice should be avoided during the medication period.

Medication monitoring for Azelnidipine (Calblock)

Blood pressure monitoring

(1) During the initial stage of treatment and dose titration, blood pressure should be measured regularly to ensure that blood pressure is stably controlled within the target range.

(2) Special attention should be paid to avoiding hypotension in elderly patients and patients with renal insufficiency.

Liver function monitoring

(1) Azelnidipine may cause elevated liver enzymes, and even hepatic dysfunction, jaundice and other abnormalities in severe cases.

(2) Regular monitoring of liver function indicators (e.g., ALT, AST, γ-GTP) is recommended after the initiation of treatment, especially for patients with pre-existing liver disease or those receiving concomitant medications that may affect hepatic metabolism.

Renal function and electrolyte monitoring

(1) For patients with renal insufficiency in particular, regular monitoring of serum creatinine, blood urea nitrogen and other indicators is required.

(2) Abnormal blood potassium levels may occur in some patients, so electrolyte levels should also be closely monitored.