Verapamil (Oral)

Verapamil is commonly used to regulate high blood pressure in adults. It is also indicated for the treatment of heart rhythm disorders (arrhythmias) and severe chest pain (angina).


Verapamil (pronounced ver AP a mil) is generally prescribed for the treatment of high blood pressure, angina, and arrhythmias. The oral route (taken by mouth) is discussed in this article, though Verapamil can also be administered intravenously.

Per the World Health Organization, Verapamil is listed as an essential medicine and is used most commonly for regulating hypertension - another name for high blood pressure.

According to the CDC, hypertension is one of the most common medical conditions in the United States, with some 75 million adults diagnosed at present.

Patients with this medical condition face a number of unique challenges. For example, if hypertension is prolonged and patients go without proper medical care for long periods of time, the end result could be fatal as organ damage to the brain, heart, and kidneys may occur. Subsequently, patients are likely to suffer a stroke, heart attack, and/or heart and kidney failure, which are among the leading causes of death in the United States.

Medical professionals, however, use Verapamil as a tool to improve patients' health and overall quality of life. The drug systematically controls high blood pressure, and in due course, it reduces life-threatening risks.

Trade Names

In the United States, medical communities refer to Verapamil by a number of trade names or brands, including:

  • Calan
  • Calan SR
  • Covera-HS
  • Isoptin SR
  • Verelan
  • Verelan PM
  • Isoptin
  • Isoptin I.V.

How it Works

In some instances, Verapamil is sufficient as a solitary treatment or it may be combined with other medicines.

Verapamil works as a calcium channel blocker, facilitating the easy transport of calcium through heart cells and blood vessels in the human body. It effectively relaxes the blood vessels and improves blood and oxygen flow to and from the heart. Patients who take Verapamil benefit from easing the burden of a previously overworked heart.

Generally, patients obtain many secondary benefits such as the ability to exercise and workout without tiring easily as a result of hypertension, angina, and arrhythmias.

Condition(s) Treated

Type of Medicine

  • Calcium channel blocker (calcium ion influx inhibitor - class-IV antiarrhythmic)

Side Effects

As with all medicines, Verapamil carries certain risks.

The most frequently reported side effects of Verapamil include constipation and headache. Taking Verapamil may also lead to excessive gas, upset stomach, indigestion, or heartburn. It could cause joint pain, muscle aches, stiff or swollen muscles as well as skin rashes, nausea, and insomnia. Cases of extreme fatigue have additionally been described by users who take Verapamil.

The not so common side effects

The following negative side effects when taking Verapamil may also take place, however, these are less commonly reported:

  • Blurred vision
  • Chest pain
  • Coughing up a pink frothy mucus
  • Difficulty breathing or shortness of breath
  • Dizziness or fainting
  • Extreme perspiration
  • Fatigue or abnormal tiredness
  • Pale blue skin, lips, or nails
  • Sore throat
  • Swollen legs or ankles
  • Tingling sensation

Some side effects go away on their own as the body acclimatises to its usage, which could take up to seven days. The side effects could be non-life-threatening, but to be safe, tell your doctor if you experience any negative symptoms after taking Verapamil.

More important, be sure to read all instructions provided at the time of your appointment as well as guidelines provided by the pharmacist dispensing the drug - as the dosage could change over time.

Verapamil may also be used in conjunction with other medicines which may cause a negative interaction. In doing so, patients can be prepared and know what to do in the event of a medical emergency. If you experience serious negative side effects, call 911 for help.

Rare side effects

Verapamil could possibly cause some rarely reported side effects, meaning, these are the exception and not the norm:

  • Feeling cold and chilly
  • On the other end of the spectrum, you may feel warm or hot
  • Experiencing cold sweats
  • Looking flushed or red in the upper body areas, such as the face, neck or chest

Like the common side effects of taking Verapamil, these adverse reactions may not necessarily mean that medical treatment is needed right away. If you are unsure, contact your doctor for advice.

Other side effects

Liver issues have also been reported such as bruising or bleeding, dark-colored urine or clay-like stools. Patients may also experience jaundice while taking Verapamil.

Snapshot of symptoms

Here is a brief rundown of the common and rare side effects of taking Verapamil in a categorized form:

Type Of Symptom | Common | Rare

  • Nervous System | Headache, Dizziness and Fatigue | Seizures
  • Cardiovascular | Hypotension and Palpitations | Chest Pain
  • Gastrointestinal | Constipation, Nausea, and Gas | Abdominal Pain and Bloating
  • Respiratory |Pulmonary Edema and Sinusitis | Laryngeal Spasm
  • Dermatologic | Scalp Irritation and Rash | Flushing
  • Psychiatric | Insomnia | Depression and Nightmares
  • Musculoskeletal | Myalgia | Muscle Fatigue
  • Hepatic | Allergic Hepatitis | Increased Liver Enzymes
  • Hypersensitivity | N/A | Rare Hypersensitivity/Allergic Reactions

It should be reiterated that patients who suffer any severe adverse reactions must seek emergency medical care immediately after noticing symptoms. Not all listed side effects may occur and in most instances, the prescribing physician makes a calculated decision that the benefits of Verapamil outweigh the risks to patients.

To report unestablished side effects of Verapamil and to help others in the process, the FDA urges patients to report any symptoms to the organization by calling 1-800-FDA-1088.


Verapamil is a prescription-only medicine that may be given alone or in conjunction with other medicines. It is otherwise referred to as a slow-channel blocker or calcium ion antagonist. The film-coated round tablets typically come in 80-120 mg doses, but this varies on a number of factors, including the trade name, pharmacy, and the patient's specific medical condition. The oral route comes in capsules and tablets as well as extended release and extended release 24-hour models.

The normal dosage for Verapamil varies from one patient to another. Based on the diagnosis, the physician will list how many times per day Verapamil is needed between specific intervals (if applicable) and for what length of time.

The standard recommendations are listed below, but this outline by no means represents the best-case-scenario for any patient:

Adult Chest Pain

80-120 mg Tablets - 3X per Day
180 mg Extended Release Tablets 24 Hour - 1X Before Bedtime

Adult Arrhythmias

240-480 mg Tablets - Split Equally 3-4X per Day for Adults

Adult Hypertension

80-120 mg Tablets - 3X per Day Initially
200 mg Extended Release Capsules - 1X Before Bedtime
180 mg Extended Release Tablets - 1X in the Morning
180 mg Extended Release Tablets 24 Hour - 1X Before Bedtime

Adjustments made over time.

How to take Verapamil?

Refer to the label on the bottle to determine the correct dosage prescribed by your medical provider. Patients should follow all directives outlined by the pharmacist.

Verapamil is taken orally in the form of a capsule or tablet. It should be swallowed whole with a full glass of water. It should not be crushed, broken, or chewed as most come with an extended release feature to help regulate high blood pressure around-the-clock.

The whole extended release tablet is sometimes excreted in the stool. If you notice this during a bowel movement, do not be alarmed. The medicine has dissolved into the bloodstream and this waste is just an empty shell.

Read the drug label to determine the best way to take Verapamil. Most pharmacists recommend taking this medicine during mealtime to lower possible side effects.

Patients that are unable to swallow the pill whole have another alternative. However, the instructions must be followed carefully in order for Verapamil to treat hypertension effectively:

  1. Grab a tablespoon of cool and soft applesauce
  2. Place a cup of ice cold water nearby
  3. Open the extended release tablet and sprinkle in the tablespoon of applesauce
  4. Consume immediately and drink with the cold cup of water

Discontinuing use

Many patients who are diagnosed with high blood pressure often report feeling "normal"and do not exhibit alarming symptoms. For this reason, hypertension could somehow be considered a silent killer if it is not pinpointed and addressed in a timely manner.

Pharmacists and medical health care professionals warn patients to take the medicine for the length of time it was prescribed, even when you don't feel sick anymore.

Follow-up appointments should also be scheduled on time to confirm if the medication is lowering hypertension and if any adjustments are needed over time.

Dosage for children, seniors, and expecting mothers

Verapamil is currently prescribed for adult users and has been excluded from pediatric indications. There are no confirmed cases of using Verapamil in children and it is considered as unsafe for minors under 18 years of age.

Expecting mothers should not be given Verapamil as clinical trials in animals have found adverse effects. However, Verapamil may be taken by nursing mothers.

Verapamil is used in seniors as no geriatric-specific problems have been described. However, since this demographic is more predisposed to certain health conditions such as heart, liver, or kidney issues, the dosage may be altered by the physician.

What happens if you miss a dose?

If you skipped a dose by accident, take Verapamil as soon as you remember. However, the dose should not be doubled up.

This simply means that if you've gone a whole day or interim without the medicine, start taking it normally but do not combine with the prior dosage with a current one.


Before taking Verapamil, it is important to inform your medical care worker about any past or current health issues. In particular, any allergic reactions should be made known to your doctor. Tell your doctor if you've ever had an allergic reaction to food products, dyes, preservatives or any fish, poultry or meats.

OTC Interactions

Contrary to popular belief, over-the-counter medicines, including NSAIDS, vitamins, or herbal products could potentially cause negative interactions with prescription medicines. As a result, list all products that you are currently taking during your consultation.

Common drug interactions with Verapamil

There are confirmed cases of negative interactions between Verapamil and certain drugs, such as:

  • Colchicine
  • Dofetilide
  • Flibanserin
  • Lomitapide

In some cases, a negative interaction between Verapamil and other drugs is very likely. However, the medical professional could determine that it still necessary to take, even with these negative side effects. In these cases where the order is continued, the dosage may be altered to offset the risks.

Some examples of negative drug interactions reported with Verapamil include but aren't limited to:

  • Acebutolol
  • Atorvastatin
  • Bisoprolol
  • Bosutinib
  • Crizotinib
  • Cyclobenzaprine
  • Dabigatran Etexilate
  • Dantrolene
  • Esmolol
  • Everolimus
  • Fentanyl
  • Fingolimod
  • Hydrocodone
  • Ivacaftor
  • Ketoconazole
  • Oxprenolol
  • Tacrolimus
  • Talinolol
  • Vincristine
  • Vincristine Sulfate Liposome

A snapshot of negative drug interactions

As these drugs may not be well-known names to the average person, here is a brief guide on categories of medicines that could react poorly to combining with Verapamil:

  • Antibiotics
  • Antifungal Treatments
  • Antivirals for HIV or AIDS
  • Aspirins
  • Beta Blockers
  • Cholesterol Drugs
  • Heart and Blood Pressure Medications
  • Medicines for Tuberculosis
  • Prostate Medicines
  • Seizure Drugs

Other substances

Tell your doctor if you smoke tobacco, drink alcohol, or consume grapefruit juice as these products reportedly cause a negative side effect when used together with Verapamil. Your doctor may advise against taking Verapamil before or during the consumption of alcohol, smoking, or grapefruit juice to reduce associated risks or any negative interactions.


Pay attention to any warnings given to you by your doctor regarding Verapamil. Some of the most common words of warning include:

  1. Follow-ups when taking Verapamil are critical to determine its efficacy and to manage any side effects. The medication should not be discontinued suddenly. Your physician will most likely adjust and moderate the medicine to slowly wean the dosage over time.
  2. Low blood pressure or hypotension may occur when taking Verapamil, which carries symptoms such as extreme dizziness, confusion, blurred vision, lightheadedness, or feeling faint. If any of these side effects occur, contact your doctor immediately.
  3. As dizziness and fainting have been reported, avoid making any sudden movements, especially when getting up or sitting down.
  4. If you drink grapefruit juice or consume any grapefruit products, inform your primary health care professional.
  5. Alcohol intake should be limited when taking Verapamil as this substance worsens low blood pressure.
  6. Certain pre-existing medical problems could influence how the physician prescribes Verapamil. Be sure to inform your primary health care provider if you have or ever had heart failure, muscle diseases, pulmonary edema, heart issues, hypotension, kidney or liver issues, or have a pacemaker installed.
  7. In addition to prescribing Verapamil, your doctor may also recommend dietary and lifestyle changes to help alleviate high blood pressure. Before starting a new routine, be sure to discuss the plan with your medical care worker to determine if these methods are safe.
  8. Certain conditions could slow down the waste removal process especially in patients with liver disease. Therefore, be sure to tell your doctor if this is the case.
  9. If an upcoming surgery is scheduled, tell the surgeon if you are taking Verapamil.
  10. Exercise caution while driving or operating machinery as Verapamil may cause confusion or distort normal thought processes.
  11. If you are pregnant, or plan to be - or you are breastfeeding - tell your healthcare worker before using Verapamil.
  12. Certain additional measures may be taken by your physician to gauge potential adverse effects, such as liver failure or risk of seizures, particularly in patients with certain preexisting conditions. For example, liver function tests may be performed and in users with hepatic, renal, or heart disorders, EEGs may be conducted for safe measure.


In order to preserve quality, Verapamil should be stored at room temperature at all times. Avoid storing in areas with high moisture content, extreme heat, or in areas of the home that gets hit by direct sunlight.

The best place to store any medication is in a high cabinet out of the reach of children and pets. Be sure to keep the Poison Control Center's number handy in the event of an overdose or exposure to infants, children, and pets. The listed number is (800) 222-1222.

Also, reseal the airtight cap to preserve the integrity of the medicine.

Periodically check your prescription medicines for the listed expiration date. Expired drugs may not work as effectively.

If your primary healthcare provider discontinues use of Verapamil, ask them for tips on disposing of any unused medicine.


Verapamil is usually prescribed as a part of a holistic treatment plan for high blood pressure. This basically means that diet, exercise, and lifestyle changes may be necessary to effectively control high blood pressure and reduce the risk of heart attacks or strokes.

The drug should be taken regularly on a daily basis and as prescribed by a medical care worker. This medicine is taken orally as a capsule or tablet typically three to four times per day. For extended release medicines, the capsule or tablet is taken by mouth once a day in the morning or at nighttime.

Verapamil is not a cure for hypertension, however, it is proven to be effective in regulating high blood pressure. Some patients are placed on a lifetime use, but this all depends on a variety of factors, such as age, pre-existing medical conditions, and potential risks.

In addition to treating hypertension, Verapamil lowers incidences of chest pain and moreover helps to normalize an irregular heartbeat, placing less overall pressure on the heart.