Verapamil interactions with other medications can increase or decrease their concentrations in the body and, in some cases, may cause organ damage. In addition to interacting with prescribed drugs, the medication can also cause problems with over the counter medications, alcohol, and some foods. Before patients start taking verapamil, they may want to review their complete history with a care provider to check for any contraindications, including medical conditions. A pharmacist can also provide assistance with the identification of potentially harmful interactions. It may be possible to change dosing schedules or make other adjustments to resolve the issue.
The drug is commonly recommended to treat high blood pressure, and can also be used in the management of angina and certain arrhythmias. Alcohol can interact badly with this medication, and patients who drink large amounts of grapefruit juice may also notice adverse reactions. It should also be used in conjunction with calcium supplements with care, because it is a calcium channel blocker. Patients who need calcium supplements can discuss the size and timing of the dosage to avoid verapamil interactions.
Certain underlying medical conditions can also be a cause for concern with verapamil. Patients with liver and kidney damage may not be able to take the medication safely, or could require monitoring to check for organ damage. Some heart conditions are also dangerous while on this medication. It may be necessary to undergo some testing before starting verapamil therapy to check for any potential interactions that might cause a problem. Side effects like dizziness and irregular heart rate should be reported to a care provider immediately.
Some antibiotics, antifungals, and antivirals have the potential to cause verapamil interactions. In addition, other beta blockers and drugs used to control heart rhythm may interact badly. Pain control drugs like fentanyl, along with sedatives, are known to have interactions with the drug, as is lithium. Aspirin can also cause verapamil interactions.
Patients taking medications already may want to discuss how to balance them with the verapamil. It may be possible to stagger doses or take other measures to reduce risks. In other instances, patients may need to switch to different drugs, or consider alternatives to verapamil so they can keep taking their other medications. Patients infected with the human immunodeficiency virus (HIV), for example, need to maintain their antiretroviral therapy, and may need to consider other measures to control high blood pressure. If a patient on the medication is told to start taking a new drug, it is important to discuss potential verapamil interactions and how to deal with them.
