Grapefruit or grapefruit juice is often a healthy part of many Americans' breakfasts. Breakfast is also the time of day that most people are directed to take their antidepressant prescription medications, such as Cymbalta. According to Dr. Jonny Bowden, Ph.D. and a clinical nutrition specialist, certain compounds in grapefruit can prevent your body from eliminating prescription drugs like Cymbalta from your system, and can increase the potential for side effects and overdose. This can be very dangerous. You should not eat grapefruit or drink grapefruit juice while taking Cymbalta.
Common Side Effects
Eating grapefruit will increase Cymbalta's potential side effects since the drug will remain active in your system in higher concentrations and for longer periods of time. It is not uncommon for antidepressants like Cymbalta to cause side effects. You should tell your doctor if you experience any side effects and if symptoms persist. Side effect include: nausea, vomiting, constipation, diarrhea, decreased appetite, dry mouth, night sweats, dizziness, headache, fatigue, weakness, drowsiness, muscle cramps, muscle pain and changes in your sexual desire or performance. These side effects are most common when you begin treatment with Cymbalta and should not continue.
Severe Side Effects
Mixing grapefruit or grapefruit juice with Cymbalta can also increase the potential for more severe side effects that this medication may cause. You should contact your doctor right away if you experience any serious side effects such as: unusual bleeding or bruising, dark colored urine, extreme fatigue, swelling of your abdomen, loss of appetite, itching, rash, hives, flu-like symptoms or yellowing of your skin or eyes, which may indicate jaundice. PubMed also warns that suicidal thoughts, though uncommon, can be a serious side effect of Cymbalta. If you experience this side effect, you should contact your health-care provider immediately.
Dr. Bowden, in his book "The 150 Healthiest Foods on Earth," explains how grapefruit works in your body to extend the half-life of antidepressants such as Cymbalta. Grapefruit and grapefruit juice contain three specific compounds known as furocoumarins. These furocoumarins deactivate or inhibit the CYP3A4 enzyme in your liver. This enzyme is largely responsible for breaking down prescription drugs, including antidepressants such as Cymbalta. With your CYP3A4 enzyme disabled, Cymbalta remains in your system longer, at potentially higher concentrations.
Although it may seem unlikely that simply eating a grapefruit or drinking a glass of grapefruit juice with prescription medicines would be that harmful, you should not take this warning lightly. According to Columbia University, mixing grapefruit products with prescription medications could lead you to have active doses that are more than nine times the prescribed amount. With other medications, such as blood pressure medications, results can be fatal. MayoClinic.com also suggests that you avoid oranges and other citrus fruits if you take prescription medications. Talk to your doctor if citrus fruits are a part of your diet before taking prescription medications.