Benzodiazepines and Grapefruit Juice

Physicians often do not pay attention to foods that interact with medications. This study demonstrates that this kind of ignorance may not be bliss.

Ten healthy subjects, aged 22 to 29 years, received 0.25 mg of triazolam with a standard glass (250 ml) of grapefruit juice or water. When compared with water drinkers, those given grapefruit juice had a significantly increased area under the concentration-time curve and a higher peak concentration of triazolam, as well as more drowsiness and subjective tiredness. The authors speculate that these changes were caused by the inhibition of the P450 CYP3A isoenzyme system, which metabolizes triazolam, by an unknown constituent of the juice.