Calan SR

The typical dosage of Calan SR for adults with hypertension or angina is:

• Initial Dose: 180 mg to 240 mg taken orally once daily.
• Maintenance Dose: The dose may be adjusted based on the patient’s response, up to a maximum of 480 mg per day.

Calan SR is contraindicated in patients with:

• Severe left ventricular dysfunction or heart failure.
• Severe hypotension (low blood pressure) or cardiogenic shock.
• Sick sinus syndrome or second- or third-degree AV block (unless a pacemaker is present).
• Hypersensitivity to verapamil or any of the components of the formulation.
• Atrial fibrillation or atrial flutter associated with an accessory bypass tract (Wolff-Parkinson-White syndrome).

Patients using Calan SR should be advised to:

• Take the medication exactly as prescribed, and not skip doses, even if they feel well. High blood pressure often has no symptoms, so regular use is important for controlling the condition.
• Avoid grapefruit and grapefruit juice, as they can increase the levels of verapamil in the blood and raise the risk of side effects.
• Monitor their blood pressure regularly and report any significant changes to their healthcare provider.
• Be aware of the potential for dizziness or lightheadedness, especially when starting the medication or increasing the dose. Rising slowly from sitting or lying positions can help prevent these symptoms.
• Inform their healthcare provider about all medications they are taking, including over-the-counter drugs and supplements, as Calan SR can interact with other medications.

• Constipation (most common)
• Dizziness or lightheadedness
• Nausea
• Headache
• Fatigue or weakness
• Edema (swelling of the ankles or feet)

Serious side effects can include:

• Severe Bradycardia: A very slow heart rate that may cause fainting or dizziness.
• Heart Failure: Symptoms such as shortness of breath, severe fatigue, or swelling in the legs should be reported immediately.
• Hypotension: Severe drops in blood pressure, particularly when starting the medication or increasing the dose.
• Allergic Reactions: Such as rash, itching, swelling, or difficulty breathing.

Bradycardia and Heart Block: Calan SR can slow the heart rate, which may lead to bradycardia or heart block, particularly in patients with pre-existing conduction abnormalities or those taking other medications that affect heart rate.

Heart Failure: Verapamil can worsen heart failure in patients with pre-existing conditions. Monitoring is important, and dose adjustments may be necessary.

Hepatic Impairment: Verapamil is metabolized by the liver, and patients with liver disease may require lower doses and careful monitoring.

Calan SR may interact with other medications, including:

• Beta-Blockers: Combined use can lead to additive effects on heart rate and cardiac contractility, potentially leading to severe bradycardia or heart failure.
• Digoxin: Verapamil can increase digoxin levels in the blood, raising the risk of digoxin toxicity.
• CYP3A4 Inhibitors: Such as erythromycin or ketoconazole, which can increase verapamil levels and the risk of side effects.
• Statins: Verapamil can increase the levels of certain statins (e.g., simvastatin, atorvastatin) in the blood, raising the risk of muscle toxicity (myopathy).

Patients should inform their healthcare provider of all medications and supplements they are taking to avoid potential interactions.

Alternative treatments for hypertension, angina, or arrhythmias include:

• Other Calcium Channel Blockers: Such as amlodipine or diltiazem.
• Beta-Blockers: Such as metoprolol or propranolol.
• ACE Inhibitors: Such as lisinopril or enalapril.
• Angiotensin II Receptor Blockers (ARBs): Such as losartan or valsartan.
• Diuretics: Such as hydrochlorothiazide or chlorthalidone.

The choice of treatment depends on the individual’s overall health, the specific condition being treated, and their response to previous treatments.