Isoptin SR (Oral)

Verapamil is used on its own or with other medicines to treat heart rhythm problems, severe chest pain (angina), or high blood pressure (hypertension). High blood pressure makes the heart and arteries work harder. If it lasts for a long time, it can cause the heart and arteries to not work properly. This may harm the blood vessels in the brain, heart, and kidneys, leading to a stroke, heart failure, or kidney failure. High blood pressure can also raise the risk of heart attacks. Controlling blood pressure may help reduce the chances of these issues.

Verapamil is a calcium channel blocker. It works by changing how calcium moves into the cells of the heart and blood vessels. This helps relax blood vessels and increases the amount of blood and oxygen that reaches the heart while lowering its workload.

This medicine is only available with a prescription from your doctor.

It is very important that your doctor check your progress at regular visits to ensure this medicine is working properly and to look for unwanted effects.

Low blood pressure (hypotension) may happen while taking this medicine. Contact your doctor immediately if you experience any of the following symptoms: blurred vision; confusion; severe dizziness, faintness, or lightheadedness when standing up quickly from a lying or sitting position; sweating; or unusual tiredness or weakness.

While taking this medicine, be cautious about how much alcohol you consume. Alcohol can increase dizziness and drowsiness and also lower blood pressure.

In deciding to use a medicine, the risks of taking the medicine must be weighed against the benefits. This is a decision you and your doctor will make. For this medicine, consider the following:

Allergies

Inform your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also, tell your healthcare professional if you have any other allergies, like to foods, dyes, preservatives, or animals. For non-prescription products, carefully read the label or package ingredients.

Pediatric

There have not been appropriate studies on the effects of verapamil in children. Safety and effectiveness have not been established.

Geriatric

Studies have not shown any specific problems for older adults that would limit the use of verapamil. However, older patients are more likely to have age-related heart, liver, or kidney issues that may require a dose adjustment while taking verapamil.

Breast Feeding

There are no adequate studies in women to determine the risk to infants when using this medication during breastfeeding. Consider the potential benefits and risks before taking this medication while breastfeeding.

Interactions with Medicines

Some medicines should never be used together, while others may be used together even if an interaction could happen. In these cases, your doctor may need to adjust the dose or take other precautions. It is especially important for your healthcare professional to know if you are taking any of the medicines listed below. The following interactions have been highlighted for their potential significance and are not necessarily exhaustive.

Using this medicine with any of the following is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

• Colchicine
• Dofetilide
• Eliglustat
• Flibanserin
• Lomitapide

Using this medicine with any of the following is usually not recommended, but may be necessary in some cases. If both medicines are prescribed, your doctor may adjust the dose or frequency of one or both medicines.

• Abametapir
• Acalabrutinib
• Acebutolol
• Adenosine
• Afatinib
• Alfentanil
• Alprazolam
• Amiodarone
• Apixaban
• Aprepitant
• Atazanavir
• Atenolol
• Atorvastatin
• Avapritinib
• Benzhydrocodone
• Berotralstat
• Betaxolol
• Betrixaban
• Bisoprolol
• Bosutinib
• Brexpiprazole
• Brigatinib
• Bupivacaine
• Bupivacaine Liposome
• Buprenorphine
• Carbamazepine
• Carteolol
• Carvedilol
• Celiprolol
• Ceritinib
• Cilostazol
• Clarithromycin
• Clonidine
• Clopidogrel
• Clozapine
• Cobicistat
• Cobimetinib
• Codeine
• Conivaptan
• Cyclobenzaprine
• Dabigatran Etexilate
• Dantrolene
• Daridorexant
• Darunavir
• Deflazacort
• Digoxin
• Dihydrocodeine
• Domperidone
• Doxorubicin
• Doxorubicin Hydrochloride Liposome
• Dronedarone
• Edoxaban
• Elacestrant
• Elexacaftor
• Encorafenib
• Entrectinib
• Epirubicin
• Eplerenone
• Erythromycin
• Esmolol
• Everolimus
• Fedratinib
• Fentanyl
• Fexinidazole
• Finerenone
• Fingolimod
• Fluconazole
• Fosaprepitant
• Fosnetupitant
• Gepirone
• Hydrocodone
• Ibrutinib
• Ifosfamide
• Infigratinib
• Itraconazole
• Ivabradine
• Ivacaftor
• Ivosidenib
• Ketoconazole
• Labetalol
• Lacosamide
• Larotrectinib
• Lefamulin
• Lemborexant
• Levobunolol
• Lovastatin
• Lumateperone
• Lurasidone
• Lurbinectedin
• Mavacamten
• Melphalan
• Meperidine
• Mepivacaine
• Methadone
• Metipranolol
• Metoprolol
• Mitapivat
• Mobocertinib
• Morphine
• Morphine Sulfate Liposome
• Nadolol
• Naloxegol
• Nebivolol
• Neratinib
• Netupitant
• Nilotinib
• Olaparib
• Omaveloxolone
• Oxprenolol
• Oxycodone
• Pacritinib
• Palbociclib
• Palovarotene
• Pemigatinib
• Penbutolol
• Pentazocine
• Pexidartinib
• Phenobarbital
• Pindolol
• Piperaquine
• Pixantrone
• Ponesimod
• Pralsetinib
• Primidone
• Propranolol
• Ranolazine
• Relugolix
• Rimegepant
• Rivaroxaban
• Selpercatinib
• Selumetinib
• Simeprevir
• Simvastatin
• Siponimod
• Sirolimus
• Sirolimus Protein-Bound
• Sonidegib
• Sotalol
• Sparsentan
• Sufentanil
• Tacrolimus
• Talazoparib
• Tazemetostat
• Temsirolimus
• Tenofovir Alafenamide
• Tezacaftor
• Timolol
• Tizanidine
• Tolvaptan
• Topotecan
• Tramadol
• Ubrogepant
• Venetoclax
• Venlafaxine
• Vincristine
• Vincristine Sulfate Liposome
• Voclosporin
• Zanubrutinib
• Zolpidem

Using this medicine with any of the following may increase the risk of certain side effects, but using both medicines may be the best treatment for you. If both medicines are prescribed, your doctor may adjust the dose or frequency of one or both medicines.

• Amlodipine
• Buspirone
• Cyclosporine
• Dalfopristin
• Digitoxin
• Dutasteride
• Flecainide
• Fosphenytoin
• Indinavir
• Lithium
• Metformin
• Midazolam
• Nevirapine
• Oxcarbazepine
• Pancuronium
• Phenytoin
• Quinidine
• Quinupristin
• Rifapentine
• St John's Wort
• Suvorexant
• Tedisamil
• Telithromycin
• Tubocurarine
• Vecuronium

Interactions with Food/Tobacco/Alcohol

Some medicines should not be used at or near the time of eating food or certain types of food due to possible interactions. Using alcohol or tobacco with certain medicines may also cause interactions. The following interactions have been highlighted for their potential significance and are not necessarily exhaustive.

Using this medicine with any of the following is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or frequency of this medicine, or provide special instructions regarding food, alcohol, or tobacco use.

• Tobacco

Using this medicine with any of the following may increase the risk of certain side effects but may be unavoidable in some cases. If used together, your doctor may change the dose or frequency of this medicine, or provide special instructions regarding food, alcohol, or tobacco use.

• Ethanol
• Grapefruit Juice

Other Medical Problems

Other medical problems may affect the use of this medicine. Make sure to tell your doctor if you have any other medical issues, especially:

• Congestive heart failure or
• Muscle disease (e.g., Duchenne's muscular dystrophy, myasthenia gravis) or
• Pulmonary edema (fluid in the lungs)—Use with caution. May worsen these conditions.

• Heart block (a type of abnormal heart rhythm) or
• Heart problems (e.g., Wolff-Parkinson-White syndrome, Lown-Ganong-Levine syndrome) or
• Low blood pressure (hypotension) or
• Sick sinus syndrome (a heart rhythm problem; can be used if you have a properly working pacemaker)—Should not be used in these conditions.

• Kidney problems or
• Liver problems—Use with caution. The effects may be stronger due to slower removal of the medicine from the body.

Along with its necessary effects, this medicine may cause some unwanted effects. Not all of these side effects may happen, but if they do, they may require medical attention.

Check with your doctor right away if any of the following side effects occur:

Less common

• Blue lips and fingernails
• blurred vision
• burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• chest pain
• confusion
• coughing that sometimes produces a pink frothy sputum
• difficult, fast, noisy breathing, sometimes with wheezing
• dizziness, faintness, or lightheadedness when suddenly getting up from lying or sitting
• increased sweating
• lightheadedness, dizziness, or fainting
• pale skin
• shortness of breath
• slow or irregular heartbeat
• sore throat
• sweating
• swelling in legs and ankles
• unusual tiredness or weakness

Rare

• Chills
• cold sweats
• feeling of warmth
• redness of the face, neck, arms, and occasionally, upper chest

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Your health care professional may also provide ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

• Difficulty having a bowel movement (stool)
• headache

Less common

• Acid or sour stomach
• belching
• difficulty in moving
• heartburn
• indigestion
• joint pain
• muscle aching or cramping
• muscle pains or stiffness
• nausea
• rash
• stomach discomfort, upset, or pain
• trouble sleeping
• unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness
• swollen joints

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

In the U.S.

• Calan
• Calan SR
• Covera-HS
• Isoptin SR
• Verelan
• Verelan PM

Available Dosage Forms:

• Tablet
• Tablet, Extended Release
• Capsule, Extended Release

Therapeutic Class: Cardiovascular Agent

Pharmacologic Class: Calcium Channel Blocker

Chemical Class: Phenylalkylamine

In addition to the use of this medicine, treatment for your high blood pressure may include weight control and changes in the types of foods you eat, especially foods high in sodium. Your doctor will tell you which of these are most important for you. You should check with your doctor before changing your diet.

Many patients who have high blood pressure will not notice any signs of the problem. In fact, many may feel normal. It is very important that you take your medicine exactly as directed and that you keep your appointments with your doctor even if you feel well.

Remember that this medicine will not cure your high blood pressure, but it does help control it. You must continue to take it as directed if you expect to lower your blood pressure and keep it down. You may have to take high blood pressure medicine for the rest of your life. If high blood pressure is not treated, it can cause serious problems such as heart failure, blood vessel disease, stroke, or kidney disease.

Swallow the extended-release tablet whole with a full glass of water. Do not break, crush, or chew it. It is best to take this medicine with food.

If you cannot swallow the verapamil extended-release capsules, you may open it and sprinkle the pellets contained in the capsule on one tablespoon of applesauce. This mixture must be swallowed immediately with a glass of cool water. The applesauce should not be hot and should be soft enough to be swallowed without chewing. Do not chew or crush the pellets.

If you are taking the extended-release tablets, you may sometimes notice what looks like a tablet in your stool. This is the empty tablet shell that is left after the medicine has been absorbed.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

• For chest pain: For oral dosage form (tablets): Adults—The usual dose is 80 to 120 milligrams (mg) three times a day. Your doctor may adjust your dose if needed. Children—Use and dose must be determined by your doctor. For oral dosage form (extended-release tablets, 24 hr): Adults—At first, 180 milligrams (mg) once daily at bedtime. Your doctor may adjust your dose if needed. Children—Use and dose must be determined by your doctor.
• For heart rhythm problems:For oral dosage form (tablets): Adults—The total usual dose is 240 to 480 milligrams (mg) divided in three or four equal doses per day. Children—Use and dose must be determined by your doctor.
• For high blood pressure: For oral dosage form (tablets): Adults—At first, 80 milligrams (mg) three times a day. Your doctor may adjust your dose if needed. Children—Use and dose must be determined by your doctor. For oral dosage form (extended-release capsules): Adults—At first, 200 milligrams (mg) once daily at bedtime. Your doctor may adjust your dose if needed. Children—Use and dose must be determined by your doctor. For oral dosage form (extended-release tablets): Adults—At first, 180 milligrams (mg) once daily in the morning. Your doctor may adjust your dose if needed. Children—Use and dose must be determined by your doctor. For oral dosage form (extended-release tablets, 24 hr): Adults—At first, 180 milligrams (mg) once daily at bedtime. Your doctor may adjust your dose if needed. Children—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.