Some more CYP3A4 inhibitors
 

People following the grapefruit thread started by Albert are familiar with the argument that the enzyme CYP3A4 helps metabolize levodopa. Inhibiting it slows the metabolism and leads to more levodopa in the body. Unfortunately, CYP3A4 has the same effect on many other drugs; inhibiting CYP3A4 in effect magnifyies their dose, thus possibly leading to dangerous over-dose situations.

Evidence-Based Medicine have written a paper [1] which lists CYP3A4 inhibitors. Those shown below are some of those of moderate strength (defined as between a 2 to a 5-fold increase in AUC and a decrease in clearance of between 50 and 80%).

I thought it would be useful to look at the archives of this forum to see if anyone had reported benefits involving these substances:

- Miconazole, no mention
- Grapefruit juice [4]
- Cat's claw, not specific
- Echinacea, not specific
- Wild cherry [3, for winter cherry]
- Chamomile, not specific
- Licorice [2]

Reference

[1] "Common Medications Classified as Weak, Moderate and Strong Inhibitors of CYP3A4"
Anthony Busti
Evidence-Based Medicine, Consult, 2015
What are some common medications classified as weak, moderate and strong inhibitors of CYP3A4?

[2] https://www.neurotalk.org/parkinson-...light=licorice

[3] Post 10, https://www.neurotalk.org/parkinson-...ghlight=cherry

[4] https://www.neurotalk.org/parkinson-...ght=grapefruit

John

Reference 1 in John's post is very useful since it gives a simple table of commonly prescribed drugs which are also CYP3A4 inhibitors. It would be useful to know if any PwP , already taking levodopa in some form ir other, had noticed any effects, positive or negative, when taking these drugs prescribed for another condition.
It would also be useful to know if they were warned about possible drug-drug interactions by their Dr or pharmacist.