Because there is not a lot of scientific evidence about barberry's effects, it is not known for certain what drugs, herbs, or supplements barberry may interact with. However, it is possible that barberry may interact with the following:

Antibiotics -- Taking barberry with antibiotics may decrease the effectiveness of the antibiotics. Talk to your doctor before combining the two.

Anticoagulants (blood thinners) -- Barberry may decrease the effectiveness of blood-thinning medication. Do not take barberry if you take anticoagulants.

Antihistamines -- Barberry may increase the effects of antihistamines.

Blood pressure medication -- Barberry may increase the effects of these drugs. Do not take barberry if you take blood pressure medication.

Celecoxib (Celebrex) -- Barberry may interact with Celebrex. Talk to your doctor before combining the two.

Diuretics (water pills) -- Barberry may increase the effects of these drugs. Talk to your doctor before combing the two.

Medications for diabetes -- Barberry may lower blood sugar, making the effects of these drugs stronger. Do not take barberry if you take medications for diabetes.