ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

The Grapefruit Juice Effect. Drug Interactions and the Dangers of Grapefruit with Lipitor, Allegra, Proscor, Zoloft...

Updated on January 11, 2009

We all know that the dangers of pharmaceuticals are multiplied when taken in combination with other medications – and we are all savvy enough to read up on possible drug interactions before combining two or more medications to avoid any chance of these adverse reactions.

But avoiding grapefruit juice as well?!?

If you take any number of medications that are metabolized by a certain enzyme in the digestive tract, you should avoid grapefruit juice.

What Are Some Drugs That Are Affected by Grapefruit Juice?

This is not a complete list!!! Do not assume that not seeing a certain drug listed below means that is is safe to be taken with grapefruit!

The ADHD medication adderall's potency can be increased when taken in conjunction with grapefruit juice.

Hismanal (Astemizole) is an antihistamine type drug that although once popular, has been taken off of pharmacy shelves due to an intense reaction with grapefruit! People taking alegra should also avoid grapefruit.

Cough medication

Mamy cough medications contain dextromethorphan (Which is also used by teens to get high!) This drug is affected by grapefruit.

Seizure medications

Tegretol (Carbamazepine)

Hormones

Estradiol (Estrogen)

Heart Medications

  • Amiodarone
  • Quinidine
  • Coumadin (Blood thinner)

Sedatives

  • Diazepam
  • Halcion

Cholesterol Medications

  • Lipitor
  • Zocor
  • Mevacor

Calcium Channel Blockers

  • Pkendif
  • Cardene
  • Verepamil
  • Nifedipine
  • Nimodipine
  • Nisoldipine

Erectile Dysfunction Meds

  • Viagra
  • Cialis

Analgesics

  • Duragesic
  • Actiq
  • Sufenta
  • Alfenta

Depression Medications 

  • Zoloft
  • Luvox

What Causes the Grapefruit Juice Effect?

Eating grapefruit causes an inhibitory reaction with enzyme CYP 3A4 in the digestive tract. If you eat grapefruit, you will have less CYP 3AR available in the walls of your intestines – and these diminished levels will last for about 24 hours after the grapefruit juice consumption.

This enzyme is critical for the breakdown and metabolization of many medications. If you have lowered levels of the enzyme in the intestines, less of the medication is broken down. Less metabolized medications will have unpredictable effects – often showing increases in potency or side effects.

Breaking down less of a drug in the intestines leaves more of the drug available to cause bodily reactions.

Variable Effects

Interestingly, the grapefruit juice affect will affect people very differently, with some people finding a great effect, and others very little. Researchers believe that people have greatly differing levels of available CYP 3AR in the digestive tract, and it is this varying quantity of enzymes that causes the varying sensitivity to grapefruit juice.

What about Other Citrus Fruits?

Only grapefruit seems to have this effect on medications. Researchers aren’t exactly sure what it is in Grapefruit that causes the enzymatic reaction.

What if you are already taking a medication that interacts with grapefruit juice…and you drink grapefruit juice regularly?!?

You should ask your doctor about the grapefruit juice effect prior to starting a new medication.

If you are already taking a medication that supposedly interacts with grapefruit, and you consume grapefruit juice regularly – you should not stop eating grapefruit juice prior to talking with your doctor! Your doctor will want to talk with you about the effects of the drug in conjunction with the fruit, and may or may not ask you to make changes.

Comments

    0 of 8192 characters used
    Post Comment

    • lafamillia profile image

      lafamillia 

      6 years ago from Soutcentral Europe

      This is really ridiculous if you ask me, as a researcher of opioid and their boosters. You have to take 10 or more LITERS to feel SOME "real" difference. But, hey, yes You are right - but in small quantities it is DANGER LESS!

    • fucsia profile image

      fucsia 

      7 years ago

      Very interesting informations! Thanks for sharing!

    • wrhapsody profile image

      wrhapsody 

      8 years ago from Renton, WA

      I cant figure out how to answer your question... but methadone will show up as an opiate in a standard drug test. You will fail and not be hired UNLESS you have a up-to-date prescription in your name for the medication.

    • profile image

      RaMa 

      8 years ago

      Fur(an)ocumarine are supposed to cause the enzymatic effect I watched on television - this info is missing here.

    • kimh039 profile image

      Kim Harris 

      8 years ago

      I like how you presented the information - broke it down into small parts. Nice read.

    • Hello, hello, profile image

      Hello, hello, 

      9 years ago from London, UK

      I never knew all that. Thanks for the information.

    • kre8iv4u profile image

      kre8iv4u 

      9 years ago from Florida beaches

      What a trip. My girlfriend eats a ton of grapefruit and out of nowhere a few months ago, broke out with hives. She finally figured it out, that some years ago, she had the same reaction while taking a medicine, at the same time eating grapefruit!!!

      peace

      dawn

    • Research Analyst profile image

      Research Analyst 

      9 years ago

      Wow now this is an amazing find about how grapefruit juice can effect drug interactions, who knew!

    • fortunerep profile image

      fortunerep 

      9 years ago from North Carolina

      I just saw this warning on my medication today with is a benzo, not valium but xanax.  How uncanny this is and very important. Great Hub

      dori

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://hubpages.com/privacy-policy#gdpr

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)