Drug–Remedy Interactions

St. John's Wort × Digoxin

⚠️ Subtherapeutic digoxin levels, worsened heart failure.

Garlic (Allium sativum) × Warfarin / Anticoagulants

⚠️ Increased bleeding risk. Case reports of spontaneous spinal epidural hematoma.

Garlic (Allium sativum) × Saquinavir / HIV Protease Inhibitors

⚠️ Subtherapeutic antiretroviral levels.

Valerian × Benzodiazepines / Sedatives / Barbiturates

⚠️ Excessive sedation, respiratory depression.

Valerian × General anesthesia

⚠️ Prolonged sedation, delayed recovery from anesthesia.

Kava (Piper methysticum) × Hepatotoxic drugs (acetaminophen, statins, methotrexate)

⚠️ Liver damage. Kava alone has caused hepatic failure in rare cases.

Kava (Piper methysticum) × Benzodiazepines / Alcohol / Sedatives

⚠️ Excessive sedation, coma in extreme cases.

Citrus Bioflavonoids / Grapefruit × Statins (simvastatin, atorvastatin, lovastatin)

⚠️ Dramatically increased statin levels → rhabdomyolysis risk.

Citrus Bioflavonoids / Grapefruit × Calcium channel blockers (felodipine, nifedipine, amlodipine)

⚠️ Severe hypotension, edema, headache.

Echinacea × Immunosuppressants (cyclosporine, tacrolimus, mycophenolate)

⚠️ Potential organ rejection in transplant patients. Autoimmune flares.

Ashwagandha (Withania somnifera) × Thyroid hormones (levothyroxine) / Antithyroid drugs

⚠️ Hyperthyroidism symptoms in combination with levothyroxine. May oppose antithyroid drugs.

Berberine × Cyclosporine

⚠️ Cyclosporine toxicity (nephrotoxicity, hepatotoxicity).