Lacerol Cor Retard (Diltiazem Hydrochloride)

Diltiazem acts on the cardiovascular system to manage several related conditions.

• Hypertension: lowers elevated blood pressure by relaxing vascular smooth muscle.
• Angina pectoris: reduces frequency and severity of chest pain by improving myocardial oxygen supply.
• Stable angina: enhances exercise tolerance and decreases anginal episodes.
• Rate control in atrial fibrillation: slows ventricular response by decreasing conduction through the atrioventricular node.

• Diltiazem inhibits the influx of calcium ions through L‑type calcium channels in vascular smooth muscle and cardiac myocytes. This results in vasodilation, reduced peripheral resistance, and decreased myocardial contractility, leading to lower blood pressure and heart rate. In the cardiac conduction system, it slows atrioventricular nodal conduction, aiding rate control in atrial fibrillation.

Common Side Effects

• Headache: mild to moderate pain often occurring early in therapy.
• Dizziness: sensation of light‑headedness, especially when standing quickly.
• Flushing: transient warmth and redness of the skin.
• Peripheral edema: swelling of the lower extremities due to fluid retention.
• Constipation: reduced bowel motility leading to hard stools.
• Nausea: mild upset stomach or feeling of queasiness.

Serious or Rare Side Effects

• Severe bradycardia: markedly slow heart rate requiring medical attention.
• Atrioventricular block: impaired electrical conduction that may need pacing.
• Significant hypotension: dangerous drop in blood pressure causing faintness.
• Liver enzyme elevation: abnormal liver function tests indicating hepatic stress.
• Allergic reactions: rash, itching, or swelling that may progress to anaphylaxis.
• Heart failure exacerbation: worsening symptoms in susceptible patients.

Before initiating therapy, consider the following precautions.

• Monitor blood pressure: check regularly to ensure therapeutic control.
• Assess heart rate: watch for bradycardia, especially in patients on other rate‑controlling agents.
• Evaluate liver function: adjust use if hepatic impairment is present.
• Use cautiously in heart failure: may worsen symptoms due to negative inotropic effect.
• Store at room temperature: keep in the original packaging, protect from moisture and direct sunlight.

Diltiazem may interact with several medicines; some require avoidance while others need monitoring.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole): can markedly increase diltiazem levels.
• Beta‑blockers: combined use may cause excessive bradycardia or heart block.
• Digoxin: diltiazem can raise digoxin concentrations, increasing toxicity risk.

Moderate Interactions (Monitor Closely)

• Antacids: may reduce diltiazem absorption; separate dosing by at least 2 hours.
• NSAIDs: can attenuate the antihypertensive effect of diltiazem, requiring blood pressure monitoring.