Grapefruit contains large number of antioxidants, which block the action of the enzyme CYP3A4 for the duration of approximately 24 hours. This enzyme is generated by the body’s liver and is carries the function of breaking down medications, including Valium as well. Hence, high amounts of grapefruit will block the action of this enzyme and further reduce its clearance from patient’s body. In addition, excessive grapefruit presence in the diet can cause potentially toxic and abnormally high Valium levels. Grapefruit is also able to inhibit the metabolism of other medications, as well as certain cholesterol-lowering drugs, blood pressure drugs and anti-anxiety drugs.
Grapefruit juice decreases the ability of your gut to process certain benzodiazepines like: diazepam, triazolam and midazolam. As result, the level of Valium may increase in your blood and cause more side effects than usual. Hence, Valium treatment course, you should avoid eating any grapefruits or drinking grapefruit juice. As an alternative, you may select other citrus beverage (e.g. orange juice).