Coleus - Warfarin Interaction

Interaction Details

Warfarin is classified as belonging to the following category: Cytochrome P450 2C9 (Cyp2C9) Substrates

Research on the effect of coleus on cytochrome P450 2C9 (CYP2C9) is conflicting. Some animal research shows that coleus extract can induce CYP2C9, while in vitro research shows that coleus can inhibit CYP2C9. Theoretically, taking coleus with drugs metabolized by CYP2C9 might affect drug levels and the risk of adverse effects. Until more is known, advise patients that taking coleus might increase or decrease levels of drugs metabolized by CYP2C9.
Some drugs metabolized by CYP2C9 include celecoxib (Celebrex), diclofenac (Voltaren), fluvastatin (Lescol), glipizide (Glucotrol), ibuprofen (Advil, Motrin), irbesartan (Avapro), losartan (Cozaar), phenytoin (Dilantin), piroxicam (Feldene), tamoxifen (Nolvadex), tolbutamide (Tolinase), torsemide (Demadex), and S-warfarin (Coumadin).

Interaction Rating

Likelihood of Occurrence

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists

References

• Yokotani K, Chiba T, Sato Y, et al. Hepatic cytochrome P450 mediates interaction between warfarin and Coleus forskohlii extract in vivo and in vitro. J Pharm Pharmacol. 2012;64(12):1793-801.

Interaction Details

Warfarin is classified as belonging to the following category: Cytochrome P450 3A4 (Cyp3A4) Substrates

In vitro research shows that coleus can activate the nuclear receptor, pregnane X receptor (PXR), which results in increased expression of CYP3A4. Theoretically, coleus might induce CYP3A4 and decrease levels of drugs metabolized by this enzyme. Although the clinical significance of this is not known, use caution when considering concomitant use of coleus and other drugs affected by these enzymes. Drugs that might be affected include some calcium channel blockers (diltiazem, nicardipine, verapamil), chemotherapeutic agents (etoposide, paclitaxel, vinblastine, vincristine, vindesine), antifungals (ketoconazole, itraconazole), glucocorticoids, cisapride (Propulsid), alfentanil (Alfenta), fentanyl (Sublimaze), losartan (Cozaar), fluoxetine (Prozac), midazolam (Versed), omeprazole (Prilosec), ondansetron (Zofran), propranolol (Inderal), fexofenadine (Allegra), and numerous others.

Interaction Rating

Likelihood of Occurrence

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists

References

• Ding, X. and Staudinger, J. L. Induction of drug metabolism by forskolin: the role of the pregnane X receptor and the protein kinase a signal transduction pathway. J Pharmacol Exp Ther 2005;312(2):849-856.
• Staudinger, J. L., Ding, X., and Lichti, K. Pregnane X receptor and natural products: beyond drug-drug interactions. Expert.Opin Drug Metab Toxicol 2006;2(6):847-857.

Interaction Details

Warfarin is classified as belonging to the following category: Anticoagulant/Antiplatelet Drugs

There is some evidence forskolin, a constituent of coleus, can inhibit platelet aggregation and adhesion. Theoretically, concomitant use of coleus and anticoagulant or antiplatelet drugs might increase the risk of bruising and bleeding. Some anticoagulant and antiplatelet drugs include abciximab (ReoPro), anagrelide (Agrylin), antithrombin III (Thrombate III), ardeparin (Normiflo), cilostazol (Pletal), clopidogrel (Plavix), dalteparin (Fragmin), danaparoid (Orgaran), dicumarol, dipyridamole (Persantine), enoxaparin (Lovenox), eptifibatide (Integrilin), heparin, lepirudin (Refludan), tirofiban (Aggrastat), and warfarin (Coumadin).

Interaction Rating

Likelihood of Occurrence

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists

References

• Christenson JT, Thulesius O, Nazzal MM. The effect of forskolin on blood flow, platelet metabolism, aggregation and ATP release. Vasa 1995;24:56-61.
• Agarwal KC, Zielinski BA, Maitra RS. Significance of plasma adenosine in the antiplatelet activity of forskolin: potentiation by dipyridamole and dilazep. Thromb Haemost 1989;61:106-10.
• Agarwal KC, Parks RE. Forskolin: a potential antimetastatic agent. Int J Cancer 1983;32:801-4.

Interaction Details

Warfarin is classified as belonging to the following category: Warfarin (Coumadin)

Preliminary research assessing the effect of coleus on warfarin metabolism is conflicting. Animal research shows that coleus extract induces cytochrome P450 2C9 (CYP2C9) enzymes and increases metabolism of warfarin; however, in vitro research shows that coleus inhibits CYP2C9 enzymes and might reduce warfarin metabolism. Until more is known, advise patients to use coleus cautiously or avoid it if they taking warfarin.

Interaction Rating

Likelihood of Occurrence

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists

References

• Yokotani K, Chiba T, Sato Y, et al. Hepatic cytochrome P450 mediates interaction between warfarin and Coleus forskohlii extract in vivo and in vitro. J Pharm Pharmacol. 2012;64(12):1793-801.

Warfarin Overview

• Warfarin is used to prevent blood clots from forming or growing larger in your blood and blood vessels. It is prescribed for people with certain types of irregular heartbeat, people with prosthetic (replacement or mechanical) heart valves, and people who have suffered a heart attack. Warfarin is also used to treat or prevent venous thrombosis (swelling and blood clot in a vein) and pulmonary embolism (a blood clot in the lung). Warfarin is in a class of medications called anticoagulants ('blood thinners'). It works by decreasing the clotting ability of the blood.

Coleus - More Interactions

Coleus interacts with 869 drugs

Interaction Rating Key

These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.