Indications 

Isoptin SR is a prescribed medication used to control essential hypertension, a high blood pressure without a known cause. 

Classified as a calcium-channel blocker, Isoptin SR works to lower blood pressure by reducing systemic vascular resistance (resistance against blood flow in the blood vessels throughout the body). It helps to relax and widen the blood vessels, making it easier for blood to flow, which subsequently reduces the resistance the heart has to pump against. 

Uses and Dosage 

Read the provided medication guide and patient information leaflet for Isoptin SR before initial use and with each prescription refill. Consult your doctor or pharmacist for any questions or additional information needed. 

The appropriate dosage of Isoptin SR is established according to the patient’s medical condition and their response to the treatment. 

Typically, this medication is taken with food, either once in the morning or at intervals of every 12 hours, as prescribed by the doctor. 

For best outcomes, adhere to a consistent daily schedule by taking Isoptin SR at around the same times each day, following your doctor’s instructions precisely. 

Continue taking Isoptin SR even if you feel fine, as individuals with high blood pressure often do not experience symptoms. Consult your doctor before discontinuing the medication. 

Side Effects 

Common Side Effects 

• Constipation 
• Headache, dizziness 
• Abnormal liver function test results 

If any of the side effects above continue or worsen, promptly notify your doctor. 

Serious Side Effects 

• Chest pain, rapid or slow heart rate 
• Feeling lightheaded, fainting 
• Shortness of breath, swelling, sudden weight gain 
• Lung problems: 
  • Anxiety 
  • Sweating 
  • Pale skin 
  • Wheezing 
  • Difficulty breathing 
  • Coughing with foamy mucus 
• Liver problems: 
  • Loss of appetite 
  • Upper stomach pain 
  • Fatigue 
  • Easy bruising or bleeding 
  • Dark urine 
  • Pale stools 
  • Jaundice (yellowing of skin or eyes) 

Contact your doctor right away if any of the above-listed serious side effects occur. 

Allergic Reactions 

Although rare, a severe allergic reaction to Isoptin SR can occur. Seek immediate medical assistance if you notice symptoms such as: 

• Hives 
• Face, tongue, or throat swelling 
• Breathing difficulties 

This list does not include all potential side effects of Isoptin SR. Inform your healthcare provider or pharmacist should you experience any unlisted effects. 

Cautions 

Before starting treatment with Isoptin SR, inform your doctor if you have any known allergies, particularly to verapamil or any of the ingredients in this prolonged release tablet. 

Disclose your medical background to your doctor before taking Isoptin SR to assess its appropriateness for your condition, particularly if you have a history of: 

• Specific heart rhythm issues (second- or third-degree atrioventricular block, sick sinus syndrome without a pacemaker, Wolff-Parkinson-White syndrome, Lown-Ganong-Levine syndrome) 
• Heart failure 
• Specific muscle/nerve disorders (muscular dystrophy, myasthenia gravis) 
• Liver disease 
• Kidney disease 

Inform your doctor about all your medications, including prescriptions and nonprescription medicines, vitamins, and herbal supplements, to minimize the risk of drug interaction with Isoptin SR. 

Some of the products that may interact with Isoptin SR include: 

• Aliskiren 
• Clonidine 
• Disopyramide 
• Dofetilide 
• Fingolimod 
• Lithium 

Various medications can influence the elimination of Isoptin SR from the body, potentially impacting its effectiveness. Examples include: 

• Erythromycin 
• Rifamycins (such as rifampin) 
• Ritonavir 
• St. John’s wort 

Isoptin SR can reduce the elimination of other medications from the body, potentially impacting their efficacy. Affected drugs may include: 

• Asunaprevir 
• Colchicine 
• Elacestrant 
• Fezolinetant 
• Flibanserin  
• Ivabradine 
• Lomitapide 
• Midazolam 
• Triazolam 

Certain products contain components that might elevate heart rate or blood pressure. Inform your pharmacist about the products you use and inquire about their safe usage, particularly concerning cough-and-cold medications, dietary supplements, or NSAIDs like ibuprofen or naproxen. 

Concomitant use of disopyramide with Isoptin SR should be avoided within a 48-hour window before or a 24-hour window after administration. 

Inform your surgeon in advance if you are using Isoptin SR and require surgery. 

The use of Isoptin SR can potentially diminish cognitive abilities and response time. Exercise caution when driving or participating in tasks that necessitate attentiveness. 

Avoid sudden movements when transitioning from sitting to lying down, as it may result in dizziness while in Isoptin SR treatment. Instead, rise slowly and ensure your stability to minimize the risk of falling. 

The impact of Isoptin SR on the health of unborn infants remains unclear. Notify your doctor if you are currently pregnant or have plans to conceive. 

Verapamil can be transferred into breast milk and might lead to side effects in the nursing infant. Refrain from breastfeeding while taking Isoptin SR.