The media has reported on many different drug interactions as well as herb and drug interactions. Natural foods and juices can also cause ill effects when combined with certain drugs. As more drugs make their way onto the market, the potential for negative interactions grows. There are also certain foods that can increase or decrease the intended activity of drugs. The important thing to know is these interactions exist and to be upfront with doctors and pharmacists about any herbs, supplements and medications you will take at the same time.
Beta Blocker
The Mayo Clinic defines beta blockers as a category of prescription drugs that block beta-adrenergic signals or hormones. These medicines block the effect of epinephrine, or adrenaline, which causes the heart to beat slower and with less force, thereby reducing overall blood pressure. An additional action of beta blockers is to cause the blood vessels to relax and dilate as another way to lower blood pressure. Doctors often prescribe these drugs for heart problems, chest pain and glaucoma as well as blood pressure.
Interactions with Beta Blockers
Beta-blocking drugs can have their effects increased or decreased by many different items. Other medications to treat blood pressure, depression, allergies, diabetes and asthma can increase the interaction of beta blockers. Drink and medication options such as caffeine, over the counter cough and cold medications, antacids and alcohol can decrease beta blocker effects. Currently there is no evidence of grapefruit juice interacting with any type of beta blockers.
Grapefruit Juice
Grapefruit juice does interact with blood pressure medications such as calcium channel blockers. Other medications that grapefruit and its juice can interact with are statins, certain oral contraceptives and benzodiazepines, according to Merck Manuals. Drinking as little as 8 oz. of juice can have lasting effect in the body for up to 72 hours, according to an article published in the "American Family Physician" journal in August 2006. While doctors once believed it was safe to drink grapefruit juice at a separate time from the medications, they now know that grapefruit has much longer-lasting effects. If a person wishes to continue consuming grapefruit juice, it is important to talk with a doctor about alternative medication options.
Other Fruits
While sweet orange juice is safe, the Mayo Clinic states other bitter juices like pomelo and Seville oranges have drug-interfering interactions similar to grapefruit. All of the bitter fruits work by interfering with the body's ability to absorb medications allowing the drugs to stay in the system longer and have a stronger effect. The 2006 American Family Physician article found patients taking calcium channel blockers as well as grapefruit had two to three times higher plasma levels of the drug in their systems. This can lead to toxic side effects. Since the exact ingredient in grapefruit which interferes with drug transport and absorption remains unidentified, it is hard to know what other medications will react with grapefruit juice in the future.
