Common Use

Isoptin Sr is a Ca2+-channel blocker that relaxes veins and arteries, making it easier for the heart to pump and reducing its workload. Calcium triggers smooth muscle contraction, and when its entry into myocytes is blocked, arterial muscles relax. This improves oxygen delivery to myocardial tissue and reduces total peripheral resistance, systemic blood pressure, and afterload. Isoptin Sr also slows the heart's electrical impulse conduction, decreasing the rate of contraction. It is used to treat hypertension, angina, and certain irregular heartbeats.

Dosage and Direction

Take Isoptin Sr orally with or without food. The daily dose ranges from 180-480 mg, which can be taken as a single dose or divided into two or three intakes. Always follow your doctor's prescription and never exceed the recommended dose.

Precautions

• Avoid alcohol, grapefruit juice, and grapefruit, as they can worsen side effects or interact with the medication.
• Do not rise too quickly from a sitting or lying position to avoid dizziness.

Contraindications

Isoptin Sr is contraindicated in patients with hypersensitivity to its components, severe left ventricular dysfunction, hypotension (systolic pressure less than 90 mm Hg), cardiogenic shock, sick sinus syndrome, atrioventricular block degree II-III, atrial flutter, atrial fibrillation, or accessory bypass tract syndromes like Wolff-Parkinson-White or Lown-Ganong-Levine.

Side Effects

Isoptin Sr is generally well-tolerated, but common side effects include dizziness, weakness, fainting, lower extremity swelling, rash, headache, and constipation. Severe side effects like jaundice, difficulty breathing, or rashes require immediate medical attention.

Drug Interaction

Isoptin Sr inhibits alcohol elimination and increases the efficacy of doxorubicin. Certain cytotoxic drug regimens like COPP and VAC may reduce its absorption. Co-administration with aspirin can increase bleeding risk, and chronic use can elevate serum digoxin levels, leading to toxicity. Inform your doctor about all medications, especially Disopyramide, Flecainide, Quinidine, Phenobarbital, Cyclosporin, and lithium-containing drugs. This medication may mildly alter liver test results.

Missed Dose

If you miss a dose, take it as soon as you remember. If it's almost time for the next dose, skip the missed dose and resume your regular schedule.

Overdose

Symptoms of overdose include slow heartbeat and fainting. Seek immediate medical attention if an overdose is suspected.

Storage

Store Isoptin Sr at room temperature (15-30°C or 59-86°F) away from light, moisture, pets, and children.

Disclaimer

The information provided here is general and does not cover all directions, drug interactions, or precautions. It should not be used for self-treatment or self-diagnosis. Always consult your healthcare adviser or doctor for specific instructions. We disclaim responsibility for the reliability of this information and any damages resulting from its use or self-treatment.