Verapamil 80mg Tablets

Verapamil is a non-dihydropyridine calcium channel blocker that inhibits the transmembrane influx of calcium ions into cardiac and vascular smooth muscle cells. This leads to: 1) Dilation of coronary and peripheral arteries, reducing afterload and improving myocardial oxygen supply. 2) Decreased myocardial contractility. 3) Decreased sinoatrial (SA) node automaticity and atrioventricular (AV) node conduction velocity, prolonging the PR interval and slowing heart rate.

Urgent Side Effects: Seek Medical Attention Immediately

While rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek medical help right away:

Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of liver problems, including:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Slow heartbeat
Abnormal heartbeat that is new or worsening
Severe dizziness or fainting
Shortness of breath, significant weight gain, or swelling in the arms or legs

Other Possible Side Effects

Like all medications, this drug can cause side effects. Although many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:

Dizziness or headache
Constipation

Reporting Side Effects

This list is not exhaustive, and you may experience other side effects. If you have questions or concerns about side effects, contact your doctor for medical advice. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.

Before Taking This Medication: Important Information to Share with Your Doctor

It is essential to inform your doctor about the following:

Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced.
Certain health conditions, including:
+ Heart failure (a weakened heart)
+ Specific types of abnormal heart rhythms, such as heart block, Lown-Ganong-Levine syndrome, sick sinus syndrome, or Wolff-Parkinson-White syndrome
+ Low blood pressure
+ A slow heartbeat
Medications you are currently taking, including:
+ Dofetilide, ivabradine, or quinidine
+ Beta blockers like atenolol, metoprolol, or propranolol
If you have taken disopyramide or flibanserin within the last 48 hours
* If you are breastfeeding, as you should not breastfeed while taking this medication

This list is not exhaustive, and it is crucial to discuss all your medications (prescription, over-the-counter, natural products, and vitamins) and health problems with your doctor and pharmacist. They will help determine if it is safe to take this medication with your other medications and health conditions. Never start, stop, or change the dose of any medication without consulting your doctor first.

It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.

When starting this medication, avoid driving and other activities that require alertness until you understand how it affects you. To minimize the risk of dizziness or fainting, get up slowly from a sitting or lying position, and be cautious when climbing stairs.

Follow your doctor's instructions for monitoring your blood pressure and heart rate, and undergo blood tests as recommended. Discuss any concerns or questions with your doctor.

If you have high blood pressure, consult your doctor before using over-the-counter (OTC) products that may increase blood pressure, such as cough and cold medications, diet pills, stimulants, non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen, and certain natural products or aids.

Before consuming alcohol, discuss it with your doctor. Additionally, if you regularly drink grapefruit juice or eat grapefruit, talk to your doctor about potential interactions.

If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects.

If you are pregnant or planning to become pregnant, inform your doctor. You will need to discuss the benefits and risks of using this medication during pregnancy to make an informed decision.

• Intravenous beta-blockers (concurrent use or within a few hours due to risk of severe bradycardia, AV block, and myocardial depression)
• Disopyramide (risk of severe hypotension and heart failure)
• Dantrolene (IV) (risk of cardiovascular collapse)
• Ivabradine (risk of excessive bradycardia)

• Digoxin (increases digoxin levels, risk of toxicity)
• Statins (e.g., simvastatin, lovastatin, atorvastatin - increases statin levels, risk of myopathy/rhabdomyolysis)
• Amiodarone (additive bradycardia, AV block, myocardial depression)
• Fentanyl (severe hypotension, bradycardia)
• Clonidine (additive bradycardia, AV block)
• Quinidine (hypotension, pulmonary edema)
• Carbamazepine (increases carbamazepine levels, toxicity)
• Theophylline (increases theophylline levels)
• Rifampin (decreases verapamil levels, loss of efficacy)
• Phenobarbital (decreases verapamil levels, loss of efficacy)
• Grapefruit juice (increases verapamil levels, risk of toxicity)

• Cimetidine (increases verapamil levels)
• Lithium (neurotoxicity)
• Cyclosporine, Tacrolimus, Sirolimus (increases immunosuppressant levels)
• Alpha-blockers (e.g., prazosin, terazosin - additive hypotensive effects)
• Other antihypertensives (additive hypotensive effects)
• Flecainide (additive negative inotropic and dromotropic effects)
• Buspirone (increases buspirone levels)
• Midazolam, Triazolam (increases benzodiazepine levels)
• Colchicine (increases colchicine levels, toxicity)

• Aspirin (may increase bleeding risk with high doses)
• Ethanol (may enhance hypotensive effects)

• Dizziness
• Lightheadedness
• Fainting (syncope)
• Slow heart rate (bradycardia)
• Shortness of breath
• Swelling in ankles, feet, or legs (edema)
• Chest pain (if worsening or new)
• Fatigue
• Constipation
• Headache

Category C. Verapamil should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Studies in animals have shown adverse effects, but there are no adequate and well-controlled studies in pregnant women.

Verapamil is excreted into breast milk. While the amount is small, monitor breastfed infants for adverse effects such as bradycardia, hypotension, and sedation. Use with caution, or consider an alternative drug, especially in preterm or neonates.

Oral verapamil is generally not recommended for routine use in pediatric patients due to limited data and potential for serious adverse effects, particularly in infants (e.g., severe hypotension, bradycardia, cardiac arrest). IV verapamil is used for supraventricular tachycardia (SVT) in a controlled hospital setting with careful monitoring.

Elderly patients may be more sensitive to the hypotensive and bradycardic effects of verapamil due to age-related decreases in hepatic and renal function, and increased sensitivity of the cardiovascular system. Start with lower doses (e.g., 40 mg twice daily) and titrate slowly with careful monitoring of blood pressure, heart rate, and PR interval.

• Verapamil is a potent negative inotrope and chronotrope; use with extreme caution in patients with left ventricular dysfunction, sick sinus syndrome, or second/third-degree AV block without a pacemaker.
• Constipation is a very common side effect (up to 40%); advise patients on dietary fiber, fluids, and potential need for laxatives.
• Avoid concurrent use of IV beta-blockers with verapamil due to the risk of profound bradycardia, AV block, and asystole.
• Grapefruit juice significantly increases verapamil levels; patients should be advised to avoid it.
• Monitor for signs of peripheral edema, which can occur due to vasodilation.
• Immediate-release formulations require multiple daily dosing, which can impact adherence. Extended-release formulations are available for once-daily dosing for hypertension/angina.

• Other non-dihydropyridine calcium channel blockers (e.g., Diltiazem)
• Dihydropyridine calcium channel blockers (e.g., Amlodipine, Nifedipine) for hypertension/angina
• Beta-blockers (e.g., Metoprolol, Atenolol) for hypertension, angina, and rate control in arrhythmias
• ACE inhibitors (e.g., Lisinopril) or ARBs (e.g., Valsartan) for hypertension
• Diuretics (e.g., Hydrochlorothiazide) for hypertension
• Other antiarrhythmics (e.g., Adenosine, Beta-blockers, Digoxin, Amiodarone) for SVT or other arrhythmias

If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.