Grapefruit & Sotalol

Sotalol is a heart medication prescribed to treat irregular heartbeats, targeting the heart muscle with the aim of improving its rhythm. Grapefruit interferes with several medications relating to the heart, including the antiarrythmic medications amiodarone and quinidine. However, no known interactions exist between grapefruit and sotalol. But medical information is frequently updated, so discuss concerns about combining sotalol and grapefruit with your doctor.

No FDA Warning

MedlinePlus, a service of the National Institutes of Health, does not list grapefruit as a substance that could react adversely with sotalol. Additionally, the current United States Food and Drug Administration's recent label for sotalol, approved on August 17, 2011, does not warn against grapefruit consumption while taking sotalol. The FDA does warn, however, that taking sotalol may increase your risk for arrythmia. For the first three days on this medication, the FDA advises staying in a facility that could provide cardiac resuscitation if needed.

Many Drugs Untested

According to the People's Pharmacy, the vast majority of drugs have not yet been tested to determine whether they pose problems when combined with grapefruit, so the lack of a grapefruit warning does not rule out the possibility of adverse interactions. Even though the FDA label does not warn against combining grapefruit with sotalol, you should ask your pharmacist or doctor about this before taking the medication.

Metabolizing Process

Grapefruit interferes with the metabolism of some drugs. Grapefruit inhibits the CYP34A enzyme, needed to break down many medications. If a medication depends on the CYP34A enzyme, grapefruit slows the metabolism process. If a drug isn't properly broken down, levels in the system become elevated, which can cause potentially life-threatening side effects. Since sotalol does not depend on the CYP34A enzyme, according to the FDA, grapefruit should not elevate levels the bloodstream. Sotalol is primarily eliminated through the kidneys, or by renal excretion.

Drug Interactions

A long list of medications react adversely with grapefruit, so talk to you doctor before combining grapefruit with any drugs, herbs or dietary supplements. Drugs known to interact adversely with grapefruit include calcium channel blockers, prescribed to lower blood pressure, and statins, prescribed to lower cholesterol. If you eat grapefruit or drink grapefruit juice with some calcium channel blockers, your blood pressure may drop to dangerously low levels. Grapefruit increases the risk of side effects of statins, including muscle and liver damage. Grapefruit combined with birth control pills increases the risk of blood clots. Grapefruit also affects some antidepressants, psychiatric drugs and immunosuppressants.