I started taking Valium recently and noticed that the bottle warned not to consume grapefruit of the juice at all while taking this medication. This was a issue for me because I drink hansen's natural cane sugar soda with real grapefruit extract and I had to give that up, but I really didn't want to so I read up on what it will do.
One article I came across said it would increase the potency of certain meds by 400%
http://www.mayoclinic.com/health/food-and-nutrition/AN00413
Grapefruit juice, and other grapefruit products and certain other citrus fruits can interfere with several kinds of prescription medications. Don't take these interactions lightly, as some can cause potentially dangerous health problems. Check with your doctor or pharmacist before consuming any grapefruit products or citrus fruits if you take prescription medications. You may need to eliminate grapefruit products from your diet. Simply taking your medication and grapefruit product at different times doesn't stop the interaction.
Certain chemicals that grapefruit products and citrus fruits contain can interfere with the enzymes that break down (metabolize) various medications in your digestive system. As a result, more medication stays in your body. This can increase the potency of your medication to potentially dangerous levels, causing serious side effects.
Pomelos and Seville oranges, a type of bitter orange often used to make marmalades and compotes, may have a similar effect. Researchers are identifying other foods that also may interact with medications, so check with your doctor or pharmacist if you have any concerns.
Here are a few examples of prescription medications that can have serious interactions with grapefruit products. This is not a complete list of grapefruit-medication interactions, so check with your doctor or pharmacist to see if your medication is affected.
Examples of grapefruit-medication interactions
Type of medication Medication name
Anti-anxiety Buspirone (BuSpar)
Anti-arrhythmia Amiodarone (Cordarone)
Antidepressant Sertraline (Zoloft)
Antihistamine Fexofenadine (Allegra)
Anti-retroviral Saquinavir (Invirase), indinavir (Crixivan)
Anti-seizure Carbamazepine (Carbatrol, Tegretol)
Calcium channel blocker Nifedipine (Procardia), nimodipine (Nimotop), nisoldipine (Sular)
Immunosuppressant Cyclosporine (Neoral, Sandimmune), tacrolimus (Prograf), sirolimus (Rapamune)
Statin Simvastatin (Zocor), lovastatin (Mevacor), atorvastatin (Lipitor)
I was bored so I figured I would post this to remind people to check the meds often, sometimes they forget to put those little stickers on the bottle, like my first bottle of Valium.