The Current Status of Verapamil Availability
Concerns about the availability of verapamil, a widely used calcium channel blocker, are understandable given its importance in treating conditions like high blood pressure, angina, and irregular heartbeats [1.8.5]. The primary source of confusion is the distinction between brand-name and generic versions of the drug. While it is true that several well-known brand name formulations of verapamil have been discontinued, the medication itself remains broadly accessible in its generic form [1.3.4, 1.4.1].
The U.S. Food and Drug Administration (FDA) has noted the discontinuation of brands like Calan, Calan SR, and Isoptin [1.2.1, 1.4.2, 1.4.6]. However, the FDA explicitly determined that these products were not withdrawn from the market for reasons of safety or effectiveness [1.2.1, 1.3.2]. This finding is crucial because it allows for the continued approval and marketing of abbreviated new drug applications (ANDAs) for generic verapamil hydrochloride tablets [1.2.5]. Essentially, the market has shifted from branded to generic production. Additionally, some manufacturers have discontinued their specific extended-release tablets, such as Mylan in 2021 and Teva's Verelan formulations in January 2025, but other manufacturers like Glenmark and Pfizer continue to produce verapamil tablets [1.2.4, 1.5.1].
What is Verapamil and How Does It Work?
Verapamil belongs to a class of drugs known as non-dihydropyridine calcium channel blockers [1.3.4]. Its primary mechanism of action involves relaxing the blood vessels, which allows the heart to pump more efficiently [1.8.5]. It achieves this by blocking the entry of calcium into the muscle cells of the heart and arteries. This action has several therapeutic effects:
- Vasodilation: By relaxing the smooth muscles in the artery walls, verapamil widens the blood vessels, which lowers blood pressure [1.8.4].
- Negative Chronotropic Effect: It slows down the electrical activity in the heart, specifically at the atrioventricular (AV) node, which helps to control a rapid or irregular heart rate (arrhythmia) [1.6.5].
- Negative Inotropic Effect: It reduces the force of the heart's contractions, decreasing the heart's workload and its demand for oxygen, which is beneficial in treating angina (chest pain) [1.7.3].
Common Uses for Verapamil
Verapamil is a versatile medication prescribed for several cardiovascular conditions and some off-label uses:
- Hypertension (High Blood Pressure): It is a common treatment for managing high blood pressure, often used long-term [1.8.5].
- Angina Pectoris: It helps prevent chest pain by increasing the supply of blood and oxygen to the heart [1.8.5].
- Arrhythmias: It is effective in treating supraventricular tachycardias, a type of abnormally fast heartbeat originating above the ventricles [1.3.4].
- Cluster Headaches and Migraines: Though not its primary indication, verapamil is also used for the prevention of cluster headaches and migraines [1.3.4].
Side Effects and Considerations
Like all medications, verapamil can cause side effects. The most common one is constipation [1.9.2, 1.9.5]. Other common side effects include dizziness, headache, and nausea [1.9.1].
More serious side effects can occur, and patients should contact a healthcare provider if they experience symptoms like:
- Swelling of the hands, feet, or ankles [1.9.3]
- An unusually slow heartbeat [1.9.1]
- Shortness of breath [1.9.2]
- Severe dizziness or fainting [1.9.1]
- Signs of liver problems, such as yellowing skin or eyes [1.9.1]
It's important for patients to inform their doctor about all existing medical conditions, especially heart, liver, or kidney disease, before starting verapamil [1.9.4]. Verapamil can interact with many other drugs and grapefruit products, which can increase the concentration of the medication in the body, so a full disclosure of all medications is essential [1.5.6, 1.9.5].
Verapamil vs. Other Calcium Channel Blockers
Verapamil is often compared to other calcium channel blockers, particularly diltiazem. Both are non-dihydropyridine calcium channel blockers and share similar efficacy in managing arrhythmias and hypertension [1.7.3].
| Feature | Verapamil | Diltiazem |
|---|---|---|
| Primary Uses | Hypertension, angina, arrhythmia, cluster headache prevention [1.3.4, 1.8.5] | Angina, hypertension, arrhythmia [1.7.1, 1.6.2] |
| Negative Inotropy | Stronger negative inotropic effect (reduces heart contraction force more) [1.7.3] | Less pronounced negative inotropic effect compared to verapamil [1.7.3] |
| Common Side Effect | Constipation is a very common side effect [1.9.5] | Leg swelling, dizziness, and tiredness are common [1.7.1] |
| Drug Interactions | Significant potential for drug-drug interactions [1.6.3] | Fewer significant drug-drug interactions compared to verapamil [1.6.3] |
| Formulations | Immediate-release, extended-release, and intravenous [1.8.5, 1.3.5] | Immediate-release, extended-release, and intravenous [1.7.5] |
Intravenous diltiazem is often preferred in clinical practice for acute rate control because it is thought to have less significant hypotensive effects [1.6.3]. However, the choice between these medications depends on the individual patient's condition, other medications they are taking, and potential side effects [1.6.6].
Conclusion
To answer the question, has verapamil been discontinued?: No, the medication itself has not been discontinued. While major brands like Calan and Isoptin are no longer marketed, this was a business decision, not a result of safety issues [1.2.1]. Generic verapamil is widely available and remains a crucial medication for millions of patients. Patients who were previously taking a branded version have likely been switched to a generic equivalent. As with any medication, patients should consult their healthcare provider or pharmacist with any concerns about their prescription, its availability, or potential alternatives.
For more information from an authoritative source, you can visit MedlinePlus drug information on Verapamil [1.8.5].
