Does Berberine Interact With Prescription Medication?

Berberine is an alkaloid that is present in the roots of a variety of plants including:

• Hydrastis canadensis (Goldenseal)
• Berberis aquifolium (Oregon grape)

Berberine has a long history of medicinal use in both Chinese and Ayurvedic medicine. It has been utilized for a variety of indications including:

• Viral infections
• Bacterial infections
• Diabetes
• High cholesterol
• Obesity
• Glaucoma
• Ulcer healing

It is also used as a dye, due to its yellow color.

Berberine Drug Interactions

Berberine is thought to have a wide range of effects on the body and therefore could theoretically interact with many different medications. However, many potential drug interactions with berberine have not been well studied and the full extent of them isn't known. Below, we discuss some of the potential drug interactions with berberine based on the information available.

Anticoagulants

Berberine is thought to have anti-platelet properties and could potentially interact with other medications that thin the blood. These include:

• Warfarin
• Plavix
• Brilinta

Anti-Diabetic Agents

Berberine has strong evidence that it lowers blood sugar levels. While using berberine to help manage diabetes may be a good use for the supplement, it could potentially cause symptoms of hypoglycemia (low blood sugar) when combined with other medications that lower blood sugar such as:

• Insulin
• Metformin
• Glipizide
• Januvia
• Glyburide
• Glimepiride

Anti-Hypertensive Drugs

Limited evidence suggests that berberine may lower blood pressure. This could potentially cause blood pressure to drop too low in individuals already taking medication to control blood pressure. Common blood pressure medications include:

• ACE-Inhibitors (e.g. lisinopril, ramipril)
• Beta-Blockers (e.g. metoprolol, propranolol)
• Calcium Channel Blockers (e.g. Diltiazem)
• Diuretics (e.g. hydrochlorothiazide, chlorthalidone)

Drugs Metabolized By Cytochrome P450 3A4 (CYP3A4)

Preliminary evidence suggests that berberine can inhibit the metabolizing enzyme cytochrome P450 3A4 (CYP3A4). Inhibition of this enzyme can potentially increase levels of drugs metabolized by CYP3A4, which could increase the risk of side effects. CYP3A4 is responsible for the metabolism of many prescription medications. Therefore, berberine has many theoretical interactions. 

For example, one study found that berberine significantly increased the concentration of the immuno-suppressant transplant medication cyclosporine, which is metabolized via CYP3A4.

Other common drugs metabolized by CYP3A4 include:

• Lovastatin
• Clarithromycin
• Indinavir
• Viagra
• Triazolam
• Zoloft (minor)

Drugs Metabolized By Cytochrome P450 2D6 (CYP2D6)

Limited evidence suggests that berberine can inhibit the metabolizing enzyme CYP2D6. Inhibition of this enzyme can potentially increase levels of drugs metabolized by CYP2D6, which could increase the risk of side effects. Common drugs metabolized by CYP2D6 include:

• Amitriptyline
• Codeine
• Haloperidol
• Metoprolol
• Ondansetron
• Paroxetine
• Risperidone
• Tramadol
• Venlafaxine
• Bystolic
• Dextromethorphan

Drugs Metabolized By Cytochrome P450 2C9 (CYP2C9)

Lastly, limited evidence suggests that berberine can inhibit the metabolizing enzyme CYP2C9. Inhibition of this enzyme can potentially increase levels of drugs metabolized by CYP2C9, which could increase the risk of side effects. Common drugs metabolized by CYP2C9 include:

• Celebrex
• Diclofenac
• Fluvastatin
• Glipizide
• Ibuprofen
• Phenytoin
• Tamoxifen
• Warfarin

Summary

Berberine has a potential interaction with many different medications based on preliminary evidence that it can inhibit metabolizing enzymes.

The clinical significance and potential impact of these drug interactions are not well known, however.

If you are planning on adding berberine as a nutritional supplement to your diet, be sure to let your doctor know so they can monitor you for effectiveness and any potential interactions.