Prescription Required 
Formulation : 
Description
Indications
Verapamil is employed either as a monotherapy or in conjunction with other medications for the purpose of addressing cardiac arrhythmias, angina pectoris (severe chest pain), or hypertension (high blood pressure). Prolonged hypertension places an additional burden on the heart and arteries, potentially impairing their optimal functionality.
Functioning as a calcium channel blocker, verapamil exerts its effect by modulating the influx of calcium into cardiac and vascular cells. Consequently, this medication induces relaxation in blood vessels, enhancing the delivery of oxygen and blood to the heart, while simultaneously alleviating its workload.
Uses and Dosage
Follow your doctor’s instructions and take this medication orally with food. Typically, it is taken once a day in the morning or every 12 hours.
Avoid crushing or chewing extended-release tablets, as this can release the entire dose at once, increasing the risk of side effects. Check with your pharmacist to see if the tablets can be split in half, as the specific instructions may vary depending on the product. Swallow the whole or split tablet without crushing or chewing.
The dosage of the medication is determined by your medical condition and how you respond to the treatment.
To derive the maximum benefit from this medication, take it regularly. It’s helpful to take it at the same time(s) every day to help you remember.
Even if you feel well, continue taking the medication. Most individuals with high blood pressure do not experience any symptoms.
Do not discontinue this medication without consulting your doctor, as certain conditions may worsen if the drug is abruptly stopped. Your dosage may need to be gradually reduced.
For the treatment of high blood pressure, it may take up to a week before you experience the full benefits of this drug.
Inform your doctor if your condition does not improve or if it worsens, such as if your blood pressure readings remain high or increase.
Side Effects
Some side effects may occur that usually do not need medical attention:
- constipation
- heartburn
- dizziness or lightheadedness
- headache
Inform your healthcare provider immediately if you experience any serious side effects:
- swelling of the hands, feet, ankles, or lower legs
- difficulty breathing or swallowing
- slow heartbeat
- fainting
- blurred vision
- rash
- nausea
- extreme tiredness
- unusual bleeding or bruising
- lack of energy
- loss of appetite
- pain in the upper right part of the stomach
- yellowing of the skin or eyes
- flu-like symptoms
- fever
Caution
Prior to initiating verapamil, inform your healthcare provider or pharmacist about any known allergies you may have, including allergies to this particular medication or other substances. This product may contain inactive ingredients that could trigger allergic reactions or other adverse effects.
Before using this medication, disclose your complete medical history to your healthcare provider or pharmacist, particularly if you have certain types of heart rhythm problems, heart failure, specific muscle/nerve disorders (muscular dystrophy, myasthenia gravis), liver disease, or kidney disease.
This drug may induce dizziness. The consumption of alcohol or marijuana can exacerbate this dizziness. Refrain from driving, operating machinery, or engaging in activities requiring alertness until you can safely do so.
Elderly individuals may be more susceptible to the side effects of this medication, particularly constipation or swelling in the ankles/feet.
During pregnancy, the use of this medication should only occur when clearly necessary. Discuss the risks and benefits with your doctor.
Although this medication passes into breast milk, it is unlikely to cause harm to a nursing infant. Consult your doctor before breastfeeding.
Form and Strength
Calan SR is available in the following forms and strengths:
-
verapamil 24hour extended-release capsule:
- 120mg
- 180mg
- 240mg
FAQ
How long does it take Calan SR to work?
Calan SR starts to work on the day you start taking it, but it may be 1 or 2 weeks before it reaches its full effect.
Can Calan SR cause weight gain?
Yes, but it is usually water weight. A small number of people (about 2%) who take verapamil may experience edema.
Resources
- https://www.nhs.uk/medicines/verapamil/#:~:text=Verapamil%20starts%20to%20work%20on,effect%20of%20verapamil%20is%20constipation
- https://www.goodrx.com/verapamil/what-is#faqs
- https://www.mayoclinic.org/drugs-supplements/verapamil-oral-route/side-effects/drg-20071728?p=1
- https://www.webmd.com/drugs/2/drug-518/calan-sr-oral/details
- https://medlineplus.gov/druginfo/meds/a684030.html
- https://www.drugs.com/mtm/calan-sr.html
