Will grapefruit juice decrease the effect of methadone.?

Question

Will grapefruit juice decrease the effect of methadone.?

Answer 1

Grapefruit  juice and Methadone both have inhibitory effects on  the same enzyme system.  As a result, grapefruit may have a potentiating effect when ingested with methadone and may increase the concentration of Methadone in the blood.  So, if anything, grapefruit juice has the potential to INCREASE the effects of Methadone. (Similar to taking Tagament prior to your Methadone dose, just a different mechanism)

However, there are other studies that suggest that the increase in methadone serum levels are clinically insignificant (or nonexistent). In either case, the simple answer is NO.

Answer 2

no it doesnt

Answer 3

Methadone has been demonstrated to inhibit the same enzyme system as grapefruit juice. Grapefruit juice potentiates the Methadone, in other words it makes the effect stronger.....BUT this is because your body is processing it faster.....so you will get an increased effect of the Methadone......BUT it will wear off faster, and you will feel worse in the morning. My clinic advises against drinking Grapefruit juice because for some the increase can be so powerful they may have a bad reaction as if the dose was increased. However, I have found if I am extra tired in the late evenings (my clinic also doesn't offer split dosing) I can drink grapefruit juice and it is like when I first take my medication in the morning.