- 1,3-bis (2-chloroethyl)-1-nitosurea (BCNU)1,3-bis (2-chloroethyl)-1-nitosurea (BCNU): Berberine and BCNU were shown to have additive effects against six human brain tumor cell lines in vitro, which may also apply to the use of barberry in humans (59).
- AcetylcholineAcetylcholine: Berberine has been shown to sensitize dogs to the hypotensive effects of acetylcholine, which may also occur with the use of barberry in humans (40).
- Anti-arrhythmic agentsAnti-arrhythmic agents: Concurrent administration of barberry and anti-arrhythmic medication is not recommended due to the unpredictable results of combining two anti-arrhythmic therapies.
- Antibiotics (tetracyclines)Antibiotics (tetracyclines): Theoretically, the concomitant use of barberry with antibiotics may lead to a decrease in antibiotics effectiveness. One double-blind study found 100mg of berberine to decrease the efficacy of tetracycline in the treatment of cholera (24).
- Anticholinergic agentsAnticholinergic agents: Barberry has displayed anticholinergic activity (60). It has been shown to reverse the secretory properties of neostigmine in animals (61). Theoretically, combination use of barberry with anticholinergic agents may potentiate these effects. Examples include: acetophenenazine, atropine, belladonna, dicyclomine, diphenhydramine, hyosciamine, prochlorperazine, promethazine, scopolamine, trifluoperazine, triflupromazine, trihexyphenidyl.
- Anticoagulant/antiplatelets and NSAIDsAnticoagulant/antiplatelets and NSAIDs: Berberine bisulfate demonstrated the ability to stimulate platelet formation in patients with thrombocytopenia in an equivalence trial (49). Barberry may decrease the efficacy of oral anticoagulants by increasing the formation of platelets. Therefore, concomitant use of barberry and anticoagulants, such as warfarin, heparin, aspirin, and clopidogrel, should be avoided. Based on pharmacological activity and in vitro study, berberine and berberine sulfate have anti-inflammatory effects and may interact with NSAIDs (5; 4; 6).
- AntihistaminesAntihistamines: Barberry has displayed antihistaminic activity in animals (60). Theoretically, concurrent use of barberry with antihistaminic agents may result in additive effects.
- Antihypertensive agentsAntihypertensive agents: There may be additive hypotensive effects and bradycardia when combining barberry with antihypertensives, such as beta-blockers and calcium channel blockers (39). Additionally, propranolol inhibits the increase in slow-response action potential seen with berberine in vitro (62). Extracts of barberry has caused significant reductions in rat arterial blood pressure and may have similar effects in humans (63; 64).
- COX-2 inhibitorsCOX-2 inhibitors: Based on pharmacological activity and in vitro study, berberine and berberine sulfate have anti-inflammatory effects and may interact with COX-2 inhibitors (5; 4; 6). COX-2 inhibitor drugs include celecoxib (Celebrex®) and rofecoxib (Vioxx®).
- DiureticsDiuretics: Barberry contains vitamin C and may have a mild diuretic activity due to the acid content. Theoretically, barberry may increase the effects of agents with potential diuretic effects.
- Drugs metabolized through cytochrome P450 3A4 enzymesDrugs metabolized through cytochrome P450 3A4 enzymes: In vitro, barberry extract was shown to moderately inhibit CYP3A4, and should be used cautiously when taken with other medications metabolized by the CYP3A4 enzyme system (65).
- Hypoglycemic agentsHypoglycemic agents: Barberry has been shown to decrease blood sugar levels in animals (32), which may hypothetical lead to an enhancement of the hypoglycemic agent when administered with barberry due to its metformin like action (31).
- L-phenylephrineL-phenylephrine: Berberine and L-phenylephrine demonstrated additive effects in animals when administered concurrently and this effect may also occur in humans with the use of barberry and L-phenylephrine together (61).
- Sedative drugsSedative drugs: Theoretically, concomitant use of berberine may have additional effects with other sedative agents. In one animal study, berberine produced sedation and potentiated the sedative effects of pentobarbitone when administered via the intraperitoneal or intraventricular routes (66).
- YohimbineYohimbine: Berberine, an alkaloid purported to be an active ingredient of barberry, has been shown to competitively inhibit the binding of yohimbine which may or may not affect its pharmacologic actions when the two agents are administered concurrently (67). This interaction may also occur in humans ingesting both barberry and yohimbine together.
- AntibacterialsAntibacterials: The concurrent use of berberine and antibiotics may have additive killing effects.
- Anticholinergic herbs and supplementsAnticholinergic herbs and supplements: Barberry has displayed anticholinergic activity (60). Theoretically, combination use of barberry with anticholinergic agents may potentiate these effects. Examples of anticholinergic herbs include bittersweet (Solanum dulcamara), henbane (Hyoscyamus niger), and Jimson weed (Datura stramonium).
- Anticoagulant herbs and supplementsAnticoagulant herbs and supplements: Berberine was shown to increase platelet formation, therefore hypothetically is contraindicated when taken in conjunction with anti-platelet medication (49).
- Berberine-containing herbs, goldensealBerberine-containing herbs, goldenseal: Concomitant use can increase the risk of berberine toxicity. Berberine-containing herbs include: bloodroot, goldenseal, celandine, Chinese goldthread, goldthread, Oregon grape (Mahonia species), amur cork tree and Chinese corktree.
- Cytochrome P450 metabolized herbs and supplementsCytochrome P450 metabolized herbs and supplements: Berberine was shown to have a moderate effect on inhibiting the CYP450 3A4 enzymes, so use cautiously with other herbs that are metabolized through the same enzyme system (65).
- DiureticsDiuretics: Barberry contains vitamin C and may have a mild diuretic activity due to the acid content. Theoretically, barberry may increase the effects of other herbs with potential diuretic effects.
- HypoglycemicsHypoglycemics: The combination of hypoglycemics and berberine may have additive effects in lowering blood sugar (anecdotal).
- HypotensivesHypotensives: Berberine has been shown to decrease blood pressure (40; 39); therefore the conjunctive use of antihypertensives may further lower blood pressure. Extracts of barberry has caused significant reductions in rat arterial blood pressure and may have similar effects in humans (63; 64).
- SedativesSedatives: Theoretically, concomitant use of berbeine may have additional effects with other sedative agents. In one animal study, berberine produced sedation and potentiated the sedative effects of pentobarbitone when administered via the intraperitoneal or intraventricular routes (66).
- YohimbeYohimbe: Yohimbine, a constituent of yohimbe and barberry competitively interact for binding sites. In addition, due to the anti-fertile properties of berberine (68), use of yohimbe for the purpose of procreation may not be effective.
- Vitamin BVitamin B: Berberine may decrease the metabolism of vitamin B therefore the concomitant use of barberry with vitamin B should be avoided.
- Tyramine-containing foodsTyramine-containing foods: Theoretically, tyramine-containing foods- such as wine, cheese, and chocolate- may have an interaction with barberry due to berberine's effect on decreasing levels of tyramine. While treating patients with hypertyraminemia with berberine, tyramine-containing foods are not recommended (41).
- BilirubinBilirubin: Berberine was shown to displace bilirubin from albumin in both in vitro and animal studies, resulting in an increase in serum total- and direct-bilirubin concentrations (58).
- Coagulation panelCoagulation panel: Based on human study, berberine bisulfate may stimulate platelet formation in patients with thrombocytopenia (49).
- GlucoseGlucose: Barberry has been shown to decrease blood sugar levels in animals (32). Theoretically it may show similar effects in humans and alter glucose levels.
- Immune cellsImmune cells: Berbamine has been shown to inhibit neutrophils (69) and decrease the total white blood cell infiltration while lowering polymorphonuclear leukocytes (70).
- InterleukinsInterleukins: Berberine has been shown statistically inhibit interleukin 1 (IL-1) (8). Berberine has also been shown to decrease IL-8 production (71).
Copyright © 2011 Natural Standard (www.naturalstandard.com)
The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.