Verapamil

Generic name: verapamil hydrochloride · Brand names: Calan, Calan SR, Covera HS, Isoptin (no longer on the market), Verelan, Verelan PM

Quick facts

Drug class
Verapamil is a calcium ion influx inhibitor (also called a slow-channel blocker or calcium ion antagonist). MedlinePlus calls it a calcium-channel blocker.
Section
DESCRIPTION (Chartwell RX label)
Source text (exact source wording)
Verapamil hydrochloride (verapamil HCl) tablets, USP is a calcium ion influx inhibitor (slow-channel blocker or calcium ion antagonist) available for oral administration in film-coated tablets containing 40 mg, 80 mg or 120 mg of verapamil hydrochloride.
Rx or otc
Rx (DailyMed Product Type: HUMAN PRESCRIPTION DRUG)
Controlled schedule
Not a controlled substance (no schedule shown in the label)
Forms and strengths
  • Film-coated tablets (immediate release): 40 mg, 80 mg, 120 mg (this record's primary form)
  • Other forms exist (extended-release tablets, extended-release capsules, injection) and are not covered here
Generic available
Value
yes
Source
DailyMed Chartwell RX label, Marketing Category ANDA (ANDA071881)
Common use one line
Used for angina, certain irregular heart rhythms and high blood pressure.

What it is used for

Verapamil tablets are used to treat angina (including angina at rest and chronic stable angina), to help control the heart rate in people with chronic atrial flutter or atrial fibrillation (together with digitalis), to prevent repeated paroxysmal supraventricular tachycardia, and to lower high blood pressure.
Section
INDICATIONS AND USAGE (first paragraph of the hypertension text only; the rest of that section was not copied)
Medlineplus section
Why is this medication prescribed?
Source text (exact source wording)
Verapamil hydrochloride tablets are indicated for the treatment of the following:

Angina

1. Angina at rest including:

- Vasospastic (Prinzmetal's variant) angina

- Unstable (crescendo, pre-infarction) angina

2. Chronic stable angina (classic effort-associated angina)

Arrhythmias

In association with digitalis for the control of ventricular rate at rest and during stress in patients with chronic atrial flutter and/or atrial fibrillation ( see WARNINGS:Accessory bypass tract)
Prophylaxis of repetitive paroxysmal supraventricular tachycardia

Essential hypertension

Verapamil hydrochloride is indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions.
Medlineplus source text (exact source wording)
Verapamil is used to treat high blood pressure and to control angina (chest pain). The immediate-release tablets are also used alone or with other medications to prevent and treat irregular heartbeats. Verapamil is in a class of medications called calcium-channel blockers. It works by relaxing the blood vessels so the heart does not have to pump as hard. It also increases the supply of blood and oxygen to the heart and slows electrical activity in the heart to control the heart rate.

How it works

Verapamil limits the flow of calcium into the muscle cells of arteries and the heart. This slows conduction through the AV node, which slows the heart rate in atrial flutter or fibrillation, and it lowers blood pressure by decreasing systemic vascular resistance.
Section
CLINICAL PHARMACOLOGY and Mechanism of Action (angina mechanism text not copied)
Source text (exact source wording)
Verapamil hydrochloride is a calcium ion influx inhibitor (slow-channel blocker or calcium ion antagonist) that exerts its pharmacologic effects by modulating the influx of ionic calcium across the cell membrane of the arterial smooth muscle as well as in conductile and contractile myocardial cells.

Arrhythmia: Electrical activity through the AV node depends, to a significant degree, upon calcium influx through the slow channel. By decreasing the influx of calcium, verapamil hydrochloride prolongs the effective refractory period within the AV node and slows AV conduction in a rate-related manner. This property accounts for the ability of verapamil hydrochloride to slow the ventricular rate in patients with chronic atrial flutter or atrial fibrillation.

Essential hypertension: Verapamil hydrochloride exerts antihypertensive effects by decreasing systemic vascular resistance, usually without orthostatic decreases in blood pressure or reflex tachycardia

Dosage: adults

The dose is individualized by titration, and 480 mg/day should not be exceeded. For angina the usual dose is 80 mg to 120 mg three times a day, and 40 mg three times a day may be used in people who may respond more strongly. For atrial fibrillation in digitalized patients the dose ranges from 240 to 320 mg/day in divided doses, and for preventing PSVT it ranges from 240 to 480 mg/day in divided doses. For high blood pressure the usual starting dose in trials was 80 mg three times a day (240 mg/day), and there is no evidence that doses beyond 360 mg add effect. Your prescriber sets your dose.
Section
DOSAGE AND ADMINISTRATION
Source text (exact source wording)
The dose of verapamil must be individualized by titration. The usefulness and safety of dosages exceeding 480 mg/day have not been established; therefore, this daily dosage should not be exceeded. Since the half-life of verapamil increases during chronic dosing, maximum response may be delayed.

Angina: Clinical trials show that the usual dose is 80 mg to 120 mg three times a day. However, 40 mg three times a day may be warranted in patients who may have an increased response to verapamil (e.g., decreased hepatic function, elderly, etc). Upward titration should be based on therapeutic efficacy and safety evaluated approximately eight hours after dosing. Dosage may be increased at daily (e.g., patients with unstable angina) or weekly intervals until optimum clinical response is obtained.

Arrhythmias: The dosage in digitalized patients with chronic atrial fibrillation ( see PRECAUTIONS) ranges from 240 to 320 mg/day in divided (t.i.d. or q.i.d.) doses. The dosage for prophylaxis of PSVT (non-digitalized patients) ranges from 240 to 480 mg/day in divided (t.i.d. or q.i.d.) doses. In general, maximum effects for any given dosage will be apparent during the first 48 hours of therapy.

Essential hypertension: Dose should be individualized by titration. The usual initial monotherapy dose in clinical trials was 80 mg three times a day (240 mg/ day). Daily dosages of 360 and 480 mg have been used but there is no evidence that dosages beyond 360 mg provided added effect. Consideration should be given to beginning titration at 40 mg three times per day in patients who might respond to lower doses, such as the elderly or people of small stature. The antihypertensive effects of verapamil hydrochloride are evident within the first week of therapy. Upward titration should be based on therapeutic efficacy, assessed at the end of the dosing interval.

Dosage: children

Safety and effectiveness in children have not been established.
Section
Pediatric Use
Source text (exact source wording)
Safety and effectiveness in pediatric patients have not been established.

Dosage adjustments

Drug interaction caps
With verapamil, the simvastatin dose should be limited to 10 mg daily and the lovastatin dose to 40 mg daily. Lower doses of other statins such as atorvastatin may be needed.
Section
PRECAUTIONS, Drug Interactions, HMG-CoA reductase inhibitors
Source text (exact source wording)
Co-administration of multiple doses of 10 mg of verapamil with 80 mg simvastatin resulted in exposure to simvastatin 2.5-fold that following simvastatin alone. Limit the dose of simvastatin in patients on verapamil to 10 mg daily. Limit the daily dose of lovastatin to 40 mg. Lower starting and maintenance doses of other CYP3A4 substrates (e.g., atorvastatin) may be required as verapamil may increase the plasma concentration of these drugs.
Kidney
Verapamil should be used cautiously in people with impaired kidney function, who should be carefully monitored for abnormal prolongation of the PR interval or other signs of overdosage. It is not removed by hemodialysis.
Section
PRECAUTIONS, General
Source text (exact source wording)
Use in patients with impaired renal function: About 70% of an administered dose of verapamil is excreted as metabolites in the urine. Verapamil is not removed by hemodialysis. Until further data are available, verapamil should be administered cautiously to patients with impaired renal function. These patients should be carefully monitored for abnormal prolongation of the PR interval or other signs of overdosage (see OVERDOSAGE).
Liver
In people with severe liver dysfunction, approximately 30% of the dose given to people with normal liver function should be used, with careful monitoring.
Section
PRECAUTIONS, General
Source text (exact source wording)
Use in patients with impaired hepatic function: Since verapamil is highly metabolized by the liver, it should be administered cautiously to patients with impaired hepatic function. Severe liver dysfunction prolongs the elimination half-life of verapamil to about 14 to 16 hours; hence, approximately 30% of the dose given to patients with normal liver function should be administered to these patients. Careful monitoring for abnormal prolongation of the PR interval or other signs of excessive pharmacologic effects (see OVERDOSAGE)should be carried out.
Elderly
Older people may start at 40 mg three times per day, and verapamil's elimination half-life may be prolonged in the elderly.
Section
DOSAGE AND ADMINISTRATION (Essential hypertension); CLINICAL PHARMACOLOGY (Pharmacokinetics) - two separate sentences joined with |
Source text (exact source wording)
Consideration should be given to beginning titration at 40 mg three times per day in patients who might respond to lower doses, such as the elderly or people of small stature. | Elimination half-life may be prolonged in the elderly.

Missed dose

Take the missed dose as soon as you remember. If it is almost time for the next dose, skip it and keep your regular schedule. Do not take a double dose.
Source text (exact source wording)
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Overdose

Treat any verapamil overdose as serious. Call poison control at 1-800-222-1222, or 911 if the person has collapsed, had a seizure, has trouble breathing, or can't be awakened. Symptoms may include dizziness, blurred vision, slow, fast or irregular heartbeat, seizures, confusion and difficulty breathing or swallowing. Treatment is supportive and verapamil cannot be removed by hemodialysis.
Section
OVERDOSAGE
Source text (exact source wording)
Treat all verapamil overdoses as serious and maintain observation for at least 48 hours (especially Verapamil Hydrochloride Tablets SR), preferably under continuous hospital care. Delayed pharmacodynamic consequences may occur with the sustained-release formulation. Verapamil is known to decrease gastrointestinal transit time.

Treatment of overdosage should be supportive. Beta-adrenergic stimulation or parenteral administration of calcium solutions may increase calcium ion flux across the slow channel and have been used effectively in treatment of deliberate overdosage with verapamil. In a few reported cases, overdose with calcium channel blockers has been associated with hypotension and bradycardia, initially refractory to atropine but becoming more responsive to this treatment when the patients received large doses (close to 1 gram/ hour for more than 24 hours) of calcium chloride. Verapamil cannot be removed by hemodialysis. Clinically significant hypotensive reactions or high degree AV block should be treated with vasopressor agents or cardiac pacing, respectively. Asystole should be handled by the usual measures including cardiopulmonary resuscitation.
Medlineplus source text (exact source wording)
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Symptoms of overdose may include:
dizziness
blurred vision
slow, fast, or irregular heartbeat
seizures
confusion
difficulty breathing or swallowing

Storage

Store at 20° to 25°C (68° to 77°F) and protect from light. Keep out of reach of children, and away from excess heat and moisture (not in the bathroom).
Section
HOW SUPPLIED (Chartwell RX label; storage details are labeler-specific)
Source text (exact source wording)
Store at 20° to 25°C (68° to 77°F) [See USP controlled room temperature] and protect from light. Dispense in a tight, light-resistant container using a child-resistant closure.
Medlineplus source text (exact source wording)
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

Boxed warning

NONE

Contraindications

Do not use verapamil if you have severe left ventricular dysfunction, low blood pressure (systolic pressure less than 90 mm Hg) or cardiogenic shock, sick sinus syndrome (unless you have a working pacemaker), second- or third-degree AV block (unless you have a working pacemaker), atrial flutter or fibrillation with an accessory bypass tract (such as Wolff-Parkinson-White or Lown-Ganong-Levine syndromes), or a known allergy to verapamil.
Section
CONTRAINDICATIONS
Source text (exact source wording)
Verapamil HCl tablets are contraindicated in:

Severe left ventricular dysfunction (see WARNINGS)
Hypotension (systolic pressure less than 90 mm Hg) or cardiogenic shock
Sick sinus syndrome (except in patients with a functioning artificial ventricular pacemaker)
Second-or third-degree AV block (except in patients with a functioning artificial ventricular pacemaker)
Patients with atrial flutter or atrial fibrillation and an accessory bypass tract (e.g., Wolff-Parkinson-White, Lown-Ganong-Levine syndromes) (see WARNINGS)
Patients with known hypersensitivity to verapamil hydrochloride

Warnings and precautions

In clinical experience with 4,954 patients, 87 (1.8%) developed congestive heart failure or pulmonary edema. Verapamil should be avoided in people with severe left ventricular dysfunction (ejection fraction less than 30%) or moderate to severe heart failure symptoms, and in people with any degree of ventricular dysfunction who take a beta-blocker.
Heading
Heart failure
Source text (exact source wording)
Heart failure: Verapamil has a negative inotropic effect, which in most patients is compensated by its afterload reduction (decreased systemic vascular resistance) properties without a net impairment of ventricular performance. In clinical experience with 4,954 patients, 87 (1.8%) developed congestive heart failure or pulmonary edema. Verapamil should be avoided in patients with severe left ventricular dysfunction (e.g., ejection fraction less than 30%) or moderate to severe symptoms of cardiac failure and in patients with any degree of ventricular dysfunction if they are receiving a beta-adrenergic blocker ( see PRECAUTIONS, Drug interactions).
Verapamil may lower blood pressure below normal and cause dizziness. The incidence of hypotension in 4,954 patients in clinical trials was 2.5%.
Heading
Hypotension
Source text (exact source wording)
Hypotension: Occasionally, the pharmacologic action of verapamil may produce a decrease in blood pressure below normal levels, which may result in dizziness or symptomatic hypotension. The incidence of hypotension observed in 4,954 patients enrolled in clinical trials was 2.5%. In hypertensive patients, decreases in blood pressure below normal are unusual.
Liver enzyme elevations have been reported, and some cases of liver cell injury were proven by rechallenge. Periodic monitoring of liver function is prudent.
Heading
Elevated liver enzymes
Source text (exact source wording)
Elevations of transaminases with and without concomitant elevations in alkaline phosphatase and bilirubin have been reported. Such elevations have sometimes been transient and may disappear even with continued verapamil treatment. Several cases of hepatocellular injury related to verapamil have been proven by rechallenge; half of these had clinical symptoms (malaise, fever, and/or right upper quadrant pain), in addition to elevation of SGOT, SGPT, and alkaline phosphatase. Periodic monitoring of liver function in patients receiving verapamil is therefore prudent.
People with atrial fibrillation or flutter and an accessory AV pathway may be at risk of a very rapid ventricular response, so use in them is contraindicated.
Heading
Accessory bypass tract (Wolff-Parkinson-White or Lown-Ganong-Levine)
Source text (exact source wording)
Some patients with paroxysmal and/or chronic atrial fibrillation or atrial flutter and a coexisting accessory AV pathway have developed increased antegrade conduction across the accessory pathway bypassing the AV node, producing a very rapid ventricular response or ventricular fibrillation after receiving intravenous verapamil (or digitalis). Although a risk of this occurring with oral verapamil has not been established, such patients receiving oral verapamil may be at risk and its use in these patients is contraindicated ( see CONTRAINDICATIONS).
Verapamil may cause first-degree AV block and temporary slow heartbeat. Higher degrees of AV block were infrequently (0.8%) observed. Marked first-degree block or progression to second- or third-degree block requires a lower dose or, rarely, stopping verapamil.
Heading
Atrioventricular block
Source text (exact source wording)
Atrioventricular block: The effect of verapamil on AV conduction and the SA node may cause asymptomatic first-degree AV block and transient bradycardia, sometimes accompanied by nodal escape rhythms. PR-interval prolongation is correlated with verapamil plasma concentrations especially during the early titration phase of therapy. Higher degrees of AV block, however, were infrequently (0.8%) observed. Marked first-degree block or progressive development to second-or third-degree AV block requires a reduction in dosage or, in rare instances, discontinuation of verapamil HCl and institution of appropriate therapy, depending on the clinical situation.
In 120 patients with hypertrophic cardiomyopathy who received verapamil at doses up to 720 mg/day, a variety of serious adverse effects were seen, and three patients died in pulmonary edema.
Heading
Patients with hypertrophic cardiomyopathy (IHSS)
Source text (exact source wording)
Patients with hypertrophic cardiomyopathy (IHSS): In 120 patients with hypertrophic cardiomyopathy (most of them refractory or intolerant to propranolol) who received therapy with verapamil at doses up to 720 mg/day, a variety of serious adverse effects were seen. Three patients died in pulmonary edema; all had severe left ventricular outflow obstruction and a past history of left ventricular dysfunction.
Verapamil may decrease neuromuscular transmission in people with Duchenne's muscular dystrophy and may worsen myasthenia gravis. The dose may need to be lowered.
Heading
Neuromuscular transmission
Source text (exact source wording)
Use in patients with attenuated (decreased) neuromuscular transmission: It has been reported that verapamil decreases neuromuscular transmission in patients with Duchenne's muscular dystrophy, and that verapamil prolongs recovery from the neuromuscular blocking agent vecuronium, and causes a worsening of myasthenia gravis. It may be necessary to decrease the dosage of verapamil when it is administered to patients with attenuated neuromuscular transmission.

Pregnancy and breastfeeding

There are no adequate and well-controlled studies in pregnant women, so verapamil should be used during pregnancy only if clearly needed. Verapamil crosses the placental barrier. Verapamil is excreted in human milk, and the label says nursing should be discontinued while verapamil is administered. Tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding.
Section
PRECAUTIONS: Pregnancy; Nursing Mothers
Source text (exact source wording)
Pregnancy

Pregnancy Category C. Reproduction studies have been performed in rabbits and rats at oral doses up to 1.5 (15 mg/kg/day) and 6 (60 mg/kg/day) times the human oral daily dose, respectively, and have revealed no evidence of teratogenicity. In the rat, however, this multiple of the human dose was embryocidal and retarded fetal growth and development, probably because of adverse maternal effects reflected in reduced weight gains of the dams. This oral dose has also been shown to cause hypotension in rats. There are no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. Verapamil crosses the placental barrier and can be detected in umbilical vein blood at delivery.

Nursing Mothers

Verapamil is excreted in human milk. Because of the potential for adverse reactions in nursing infants from verapamil, nursing should be discontinued while verapamil is administered.
Medlineplus source text (exact source wording)
tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking verapamil, call your doctor.

Side effects

Common
In clinical trials in 4,954 patients, the reactions listed at rates greater than 1.0% were constipation 7.30%, dizziness 3.30%, nausea 2.70%, hypotension 2.50%, headache 2.20%, edema 1.90%, CHF or pulmonary edema 1.80%, fatigue 1.70%, dyspnea 1.40%, bradycardia 1.40%, total AV block 1.20% and rash 1.20%.
Threshold
rates greater than 1.0% (label wording: 'at rates greater than 1.0% or occurred at lower rates but appeared clearly drug-related in clinical trials in 4,954 patients')
Section
ADVERSE REACTIONS (table text copied in the order the printable page returned it; the label's two-column table was flattened, so name/percent pairing is as returned)
Source text (exact source wording)
The following reactions to orally administered verapamil occurred at rates greater than 1.0% or occurred at lower rates but appeared clearly drug-related in clinical trials in 4,954 patients:

Constipation 7.30%
Dyspnea 1.40%
Dizziness 3.30%
Bradycardia (HR <50/min) 1.40%
Nausea 2.70%
AV block total (1°, 2°, 3°) 1.20%
Hypotension 2.50%
2° and 3° 0.80%
Headache 2.20%
Rash 1.20%
Edema 1.90%
Flushing 0.60%
CHF, Pulmonary edema 1.80%
Fatigue 1.70%
Elevated liver enzymes ( see WARNINGS)
Less common
Second- and third-degree AV block was 0.80% and flushing was 0.60%. Other reactions reported in 1.0% or less of patients, where a causal link is uncertain, include chest pain, palpitations, fainting, diarrhea, dry mouth, bruising, confusion, insomnia, muscle cramps, hair loss, hives, blurred vision and ringing in the ears.
Section
ADVERSE REACTIONS (the label has no placebo-controlled table)
Source text (exact source wording)
2° and 3° 0.80% | Flushing 0.60% | The following reactions, reported in 1.0% or less of patients, occurred under conditions (open trials, marketing experience) where a causal relationship is uncertain; they are listed to alert the physician to a possible relationship:

Cardiovascular: angina pectoris, atrioventricular dissociation, chest pain, claudication, myocardial infarction, palpitations, purpura (vasculitis), syncope.

Digestive system:diarrhea, dry mouth, gastrointestinal distress, gingival hyperplasia.

Hemic and lymphatic: ecchymosis or bruising.

Nervous system: cerebrovascular accident, confusion, equilibrium disorders, insomnia, muscle cramps, paresthesia, psychotic symptoms, shakiness, somnolence, extrapyramidal symptoms.

Skin: arthralgia and rash, exanthema, hair loss, hyperkeratosis, macules, sweating, urticaria, Stevens-Johnson syndrome, erythema multiforme.

Special senses: blurred vision, tinnitus.

Urogenital: gynecomastia, galactorrhea/hyperprolactinemia, increased urination, spotty menstruation, impotence.
Serious
Serious reactions are uncommon when the dose is raised gradually. The label points to heart failure, low blood pressure, raised liver enzymes, AV block and rapid ventricular response, and reports infrequent paralytic ileus. MedlinePlus says to call your doctor right away or get emergency care for swelling of the hands, feet, ankles or lower legs, trouble breathing or swallowing, slow heartbeat, fainting, blurred vision, rash, extreme tiredness, unusual bleeding or bruising, pain in the upper right part of the stomach, yellowing of the skin or eyes, flu-like symptoms or fever.
Label section
ADVERSE REACTIONS and WARNINGS
Medlineplus section
What side effects can this medication cause?
Label source text (exact source wording)
Serious adverse reactions are uncommon when verapamil hydrochloride therapy is initiated with upward dose titration within the recommended single and total daily dose. See WARNINGSfor discussion of heart failure, hypotension, elevated liver enzymes, AV block, and rapid ventricular response. Reversible (upon discontinuation of verapamil) non-obstructive, paralytic ileus has been infrequently reported in association with the use of verapamil.
Medlineplus source text (exact source wording)
Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately or get emergency medical treatment :
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
Medlineplus mild
Section
MedlinePlus a684030, What side effects can this medication cause?
Source text (exact source wording)
Verapamil may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
constipation
heartburn
dizziness or lightheadedness
headache

Interactions

Drugs
Erythromycin and ritonavir (CYP3A4 inhibitors) can raise verapamil levels, and rifampin (a CYP3A4 inducer) can lower them.
Name
CYP3A4 inhibitors and inducers
Section
PRECAUTIONS, Drug Interactions, Cytochrome inducers/inhibitors
Source text (exact source wording)
Clinically significant interactions have been reported with inhibitors of CYP3A4 (e.g., erythromycin, ritonavir) causing elevation of plasma levels of verapamil while inducers of CYP3A4 (e.g., rifampin) have caused a lowering of plasma levels of verapamil.
Statins that are CYP3A4 substrates with verapamil have been linked to reports of myopathy and rhabdomyolysis. Limit simvastatin to 10 mg daily and lovastatin to 40 mg daily.
Name
Statins (simvastatin, lovastatin, atorvastatin)
Section
PRECAUTIONS, Drug Interactions, HMG-CoA reductase inhibitors
Source text (exact source wording)
The use of HMG-CoA reductase inhibitors that are CYP3A4 substrates in combination with verapamil has been associated with reports of myopathy/rhabdomyolysis.

Co-administration of multiple doses of 10 mg of verapamil with 80 mg simvastatin resulted in exposure to simvastatin 2.5-fold that following simvastatin alone. Limit the dose of simvastatin in patients on verapamil to 10 mg daily. Limit the daily dose of lovastatin to 40 mg. Lower starting and maintenance doses of other CYP3A4 substrates (e.g., atorvastatin) may be required as verapamil may increase the plasma concentration of these drugs.
Avoid using verapamil with ivabradine.
Name
Ivabradine
Section
PRECAUTIONS, Drug Interactions
Source text (exact source wording)
Ivabradine: Concurrent use of verapamil increases exposure to ivabradine and may exacerbate bradycardia and conduction disturbances. Avoid co-administration of verapamil and ivabradine.
In a few reported cases, verapamil with aspirin led to longer bleeding times than aspirin alone.
Name
Aspirin
Section
PRECAUTIONS, Drug Interactions
Source text (exact source wording)
Aspirin: In a few reported cases, co-administration of verapamil with aspirin has led to increased bleeding times greater than observed with aspirin alone.
Beta-blockers with verapamil may have additive negative effects on heart rate, AV conduction and heart contraction. Combined therapy should usually be avoided in people with AV conduction abnormalities or depressed left ventricular function.
Name
Beta-blockers
Section
PRECAUTIONS, Drug Interactions
Source text (exact source wording)
Concomitant therapy with beta-adrenergic blockers and verapamil may result in additive negative effects on heart rate, atrioventricular conduction and/or cardiac contractility.

Therefore, if combined therapy is used, close surveillance of clinical status should be carried out. Combined therapy should usually be avoided in patients with atrioventricular conduction abnormalities and those with depressed left ventricular function.
Chronic verapamil treatment can increase serum digoxin levels by 50% to 75% during the first week, which can cause digitalis toxicity, so digitalis doses should be reduced.
Name
Digitalis (digoxin)
Section
PRECAUTIONS, Drug Interactions
Source text (exact source wording)
However, chronic verapamil treatment can increase serum digoxin levels by 50% to 75% during the first week of therapy, and this can result in digitalis toxicity. ... Maintenance and digitalization doses should be reduced when verapamil is administered, and the patient should be reassessed to avoid over-or under-digitalization.
Verapamil with other blood pressure medicines usually has an additive effect on lowering blood pressure, so monitoring is needed.
Name
Antihypertensive agents
Section
PRECAUTIONS, Drug Interactions
Source text (exact source wording)
Verapamil administered concomitantly with oral antihypertensive agents (e.g., vasodilators, angiotensin-converting enzyme inhibitors, diuretics, beta-blockers) will usually have an additive effect on lowering blood pressure. Patients receiving these combinations should be appropriately monitored.
Disopyramide should not be given within 48 hours before or 24 hours after verapamil. Flecainide with verapamil may have additive effects on heart contraction and conduction. Quinidine with verapamil caused significant hypotension in a small number of people with hypertrophic cardiomyopathy.
Name
Disopyramide, flecainide, quinidine
Section
PRECAUTIONS, Drug Interactions, Antiarrhythmic agents
Source text (exact source wording)
Disopyramide: Until data on possible interactions between verapamil and disopyramide are obtained, disopyramide should not be administered within 48 hours before or 24 hours after verapamil administration.

Flecainide: A study in healthy volunteers showed that the concomitant administration of flecainide and verapamil may have additive effects on myocardial contractility, AV conduction, and repolarization.

Quinidine: In a small number of patients with hypertrophic cardiomyopathy (IHSS), concomitant use of verapamil and quinidine resulted in significant hypotension.
Verapamil with lithium can increase sensitivity to lithium effects (neurotoxicity), so both drugs need careful monitoring. Verapamil may increase levels of carbamazepine, cyclosporine and theophylline.
Name
Lithium, carbamazepine, cyclosporine, theophylline
Section
PRECAUTIONS, Drug Interactions, Other agents
Source text (exact source wording)
Lithium: Increased sensitivity to the effects of lithium (neurotoxicity) has been reported during concomitant verapamil-lithium therapy; lithium levels have been observed sometimes to increase, sometimes to decrease, and sometimes to be unchanged. Patients receiving both drugs must be monitored carefully.

Carbamazepine: Verapamil therapy may increase carbamazepine concentrations during combined therapy. This may produce carbamazepine side effects such as diplopia, headache, ataxia, or dizziness.

Cyclosporine: Verapamil therapy may increase serum levels of cyclosporine.

Theophylline: Verapamil may inhibit the clearance and increase the plasma levels of theophylline.
Rifampin may markedly reduce how much verapamil the body absorbs, and phenobarbital may increase verapamil clearance.
Name
Rifampin and phenobarbital
Section
PRECAUTIONS, Drug Interactions, Other agents
Source text (exact source wording)
Rifampin: Therapy with rifampin may markedly reduce oral verapamil bioavailability.

Phenobarbital: Phenobarbital therapy may increase verapamil clearance.
Hypotension and slow irregular heartbeats have been seen with telithromycin. Clonidine with verapamil has caused slow heartbeat needing hospitalization and a pacemaker, so heart rate should be monitored. With sirolimus, temsirolimus or everolimus, lower doses of both medicines should be considered.
Name
Clonidine, telithromycin, mTOR inhibitors
Section
PRECAUTIONS, Drug Interactions, Other agents
Source text (exact source wording)
Telithromycin: Hypotension and bradyarrhythmias have been observed in patients receiving concurrent telithromycin, an antibiotic in the ketolide class.

Clonidine: Sinus bradycardia resulting in hospitalization and pacemaker insertion has been reported in association with the use of clonidine concurrently with verapamil. Monitor heart rate in patients receiving concomitant verapamil and clonidine.

With concomitant use of mTOR inhibitors (e.g., sirolimus, temsirolimus, and everolimus) and verapamil, consider appropriate dose reductions of both medications.
Food and alcohol
Grapefruit juice may increase verapamil levels in the blood. MedlinePlus says to talk to your doctor about eating grapefruit or drinking grapefruit juice.
Name
Grapefruit juice
Section
PRECAUTIONS, Drug Interactions
Source text (exact source wording)
Grapefruit juice: Grapefruit juice may increase plasma levels of verapamil.
Verapamil may increase blood alcohol concentrations and prolong alcohol's effects.
Name
Alcohol
Section
PRECAUTIONS, Drug Interactions
Source text (exact source wording)
Alcohol: Verapamil may increase blood alcohol concentrations and prolong its effects.
Other
MedlinePlus lists St. John's wort and cimetidine as nonprescription or herbal products that may interact with verapamil.
Name
Herbal and OTC (MedlinePlus)
Section
MedlinePlus a684030, What special precautions should I follow?
Source text (exact source wording)
the following nonprescription or herbal products may interact with verapamil : St. John's wort; cimetidine (Tagamet).

Patient tips

Take verapamil exactly as directed. The regular tablet is usually taken three to four times a day. It controls but does not cure arrhythmias, high blood pressure and angina, so keep taking it even if you feel well, and do not stop without talking to your doctor. Verapamil may make the effects of alcohol more severe and longer-lasting. Talk to your doctor about grapefruit.
Label
Section
n/a
Medlineplus
Section
MedlinePlus a684030 (sentences from several paragraphs)
Source text (exact source wording)
Take verapamil exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Verapamil controls arrhythmias, high blood pressure, and angina but does not cure these conditions. Continue to take verapamil even if you feel well. Do not stop taking verapamil without talking to your doctor.

The regular tablet is usually taken three to four times a day.

Verapamil may cause the effects of alcohol to be more severe and longer-lasting.

Talk to your doctor about eating grapefruit or drinking grapefruit juice while taking this medicine.

Alternatives

Class statement
Source text (exact source wording)
Verapamil hydrochloride (verapamil HCl) tablets, USP is a calcium ion influx inhibitor (slow-channel blocker or calcium ion antagonist)
Recommendation
none (not ranked)

Frequently asked questions

Question
What is verapamil used for?
Answer
Verapamil tablets are used to treat angina, to help control the heart rate in chronic atrial flutter or atrial fibrillation together with digitalis, to prevent repeated paroxysmal supraventricular tachycardia, and to lower high blood pressure.
Source section
INDICATIONS AND USAGE
Source
DailyMed Chartwell RX label
Question
How often do I take verapamil tablets?
Answer
For angina the label says the usual dose is 80 mg to 120 mg three times a day, and for high blood pressure the usual starting dose in trials was 80 mg three times a day. MedlinePlus says the regular tablet is usually taken three to four times a day. Your prescriber individualizes the dose.
Source section
DOSAGE AND ADMINISTRATION; MedlinePlus How should this medicine be used?
Source
DailyMed Chartwell RX label; MedlinePlus a684030
Question
What should I do if I miss a dose of verapamil?
Answer
Take the missed dose as soon as you remember. If it is almost time for the next dose, skip it and go back to your regular schedule. Do not take a double dose.
Source section
What should I do if I forget a dose?
Source
MedlinePlus a684030
Question
Can I drink grapefruit juice or alcohol with verapamil?
Answer
Grapefruit juice may increase verapamil levels in the blood, and verapamil may increase blood alcohol concentrations and prolong alcohol's effects. Talk to your doctor about grapefruit and about safe use of alcohol.
Source section
PRECAUTIONS, Drug Interactions; MedlinePlus dietary and precaution sections
Source
DailyMed Chartwell RX label; MedlinePlus a684030
Question
What are the most common side effects of verapamil?
Answer
In clinical trials in 4,954 patients, the most frequent reaction was constipation at 7.30%, followed by dizziness at 3.30%, nausea at 2.70%, hypotension at 2.50% and headache at 2.20%.
Source section
ADVERSE REACTIONS
Source
DailyMed Chartwell RX label
Question
Is verapamil safe during pregnancy or breastfeeding?
Answer
There are no adequate and well-controlled studies in pregnant women, so verapamil should be used during pregnancy only if clearly needed. Verapamil is excreted in human milk, and the label says nursing should be discontinued while verapamil is administered. Tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding.
Source section
PRECAUTIONS: Pregnancy; Nursing Mothers
Source
DailyMed Chartwell RX label; MedlinePlus a684030
Question
What medicines should not be combined with verapamil?
Answer
The label says to avoid using verapamil with ivabradine. Combined use with beta-blockers should usually be avoided in people with AV conduction abnormalities or depressed left ventricular function. Simvastatin should be limited to 10 mg daily and lovastatin to 40 mg daily. Verapamil can also raise digoxin levels. Tell your doctor and pharmacist about everything you take.
Source section
PRECAUTIONS, Drug Interactions
Source
DailyMed Chartwell RX label
Question
Should I stop verapamil when I feel well?
Answer
No. Verapamil controls arrhythmias, high blood pressure and angina but does not cure them. Continue to take it even if you feel well, and do not stop without talking to your doctor.
Source section
How should this medicine be used?
Source
MedlinePlus a684030

Sources

  • DailyMed verapamil HCl tablets (primary, immediate release)
    Set id: ebc9a09a-7b5f-4df6-ace7-31185d469b28 · Label effective or revised date: Revised: 12/2025 (end of page); the label body also ends with 'Revised: 08/2023' · Dailymed version date: DailyMed list API published_date Dec 12, 2025 · Fetched at: 2026-11-02 · Sections used: Description, Clinical Pharmacology, Indications, Contraindications, Warnings, Precautions, Adverse Reactions, Overdosage, Dosage and Administration, How Supplied (whole label captured, within 50,000 characters)
  • Alternate IR tablet label candidates (not opened, revised dates NOT READ)
    Set id: a32f346e-71cf-cc11-e053-2a95a90ae88c · Label effective or revised date: NOT READ (label not opened) · Dailymed version date: published Jan 16, 2026 (list API)
  • Alternate IR tablet label candidates (not opened)
    Set id: a0343397-897b-46d6-943f-a87e07e1de10 · Label effective or revised date: NOT READ (label not opened) · Dailymed version date: published Dec 23, 2024 (list API)
  • Label opened but not usable
    Set id: 051392d3-8ec1-450c-8c38-791d4ef1a2db · Label effective or revised date: Revised: 4/2026
  • MedlinePlus Verapamil
    Label effective or revised date: Last Revised - 10/15/2017 · Fetched at: 2026-11-02
  • Drugs@FDA
  • openFDA

Information is taken from the cited sources and is for general reference only. It is not medical advice. Report side effects to FDA MedWatch at 1-800-FDA-1088. For a poison emergency call 1-800-222-1222. See prices for this drug