Warfarin Danshen

Clinicians from Hong Kong reported a case of potential danshen-warfarin interaction in a 48-year-old female with a history of rheumatic heart disease, atrial fibrillation, and mitral stenosis (11). The patient underwent successful transvenous mitral valvuloplasty for management of her medical conditions, and was discharged with 1 mg warfarin, as well as... 

Danshen Warfarin Increase effectiveness of warfarin due to reduced... 

Cheng TO. Warfarin danshen interaction. Ann Thorac Surg 1999 67 894. 

Yu CM, Chan JCN, Sanderson IE. Chinese herbs and warfarin potentiation by Danshen. J Intern Med 1997 241 337-339. 

Tam LS, Chan TYK, Leung WK, Critchley JAJH. Warfarin interactions with Chinese traditional medicines danshen and methyl salicylate medicated oil. 

Lo ACT, Chan K, Yeung JHK, Woo KS. The effects of danshen Salvia miltior-rhiza) on pharmacokinetics and dynamics of warfarin in rats. Eur J Drug Metab Pharmacokinet 1992 17 257-262. 

Warfarin Danshen (Salvia miltiorrhiza) Increased INR, prolonged PT/PTT Danshen decreases elimination of warfarin... 

The available evidence contraindicates concurrent use of danshen and warfarin. 

Potentiation of the effect of warfarin by danshen (the root of Salvia miltiorrhizd), a widely used traditional Chinese herbal medicine, particularly for cardiovascular complaints, has been described in a 62-year-old man with a mechanical mitral valve prosthesis (159). 

A patient taking warfarin and who had taken a decoction of S. miltiorrhiza presented with a prolonged bleeding time and melena (12) and other cases have been reported (13). Pharmacodynamic and pharmacokinetic studies in rats have shown that danshen increases the absorption rate constant, AUC, and half-lives of both R- and 5-warfarin, and reduces their clearances and apparent volumes of distribution (14,15). 

Chan lY. Interaction between warfarin and danshen Salvia miltiorrhiza). Ann Pharmacother 2001 35(4) 501. ... 

Chan K, Lo AC, Yeung JH, Woo KS. The effects of Danshen Salvia miltiorrhiza) on warfarin pharmacodynamics and pharmacokinetics of warfarin enantiomers in rats. J Pharm Pharmacol 1995 47(5) 402-6. 

St John s wort is the most well established example of a herb that can induce the metabolism of drugs, principally by the cytochrome P450 isoenzyme CYP3A4. This herb appears to have a modest effect on warfarin , (p.418), which might be clinically important. Danshen , (p.415) might interact by increasing the bioavailability of warfarin. No other herbs appear to have an established effect on the metabolism of warfarin. 

Two case reports and some animal data indicate that Danshen, a Chinese herbal remedy, can increase the effects of warfarin, resulting in bleeding. 

Lo ACT, ChanK, Yeui JHK, WooKS. The effects of Danshen (SahnamiUiorrhizd) phar-macddnetics and (fynamics of warfarin in rats. EurJDrugMet Pharmacdcinet ( 992) 17, 257-62. 

Another report describes a man taking warfarin, digoxin, captopril and furosemide with an INR of about 3, who developed chest pain and breathlessness about 2 weeks after starting to take Danshen. He was found to have a massive pleural effusion, which was later drained of blood, and an USTR of more than 8.4. He was later discharged on his usual dose of warfarin with an INR stable at 3, in the absence of the Danshen ... 

Not fully understood. Studies in rats show Danshen can increase the bioavailability of bothR- and S -warfarin thereby increasing its effects. ... 

Methyl salicylate, in the form of gels, oil, or ointment applied to the skin, has been found to increase the effects of warfarin. Bleeding and bruising and/or raised INRs have been seen with both high " and low doses of methyl salicylate. One report described the possible additive effects of methyl salicylate oil (Kwan Loong Medicated Oil) and a decoction of Danshen (the root of Salvia miltiorrhiza) on the response to warfarin (see also Coumarins and related drugs + Herbal medicines Danshen (Salvia miltiorrhizay, p.415). A raised prothrombin time has also been reported with topical trolamine salicylate. ... 

Tam, L.S., T.Y.K. Chan, W.K. Leung, and J. Critchley. 1995. Warfarin interactions with Chinese traditional medicines Danshen and methyl salicylate medicated oil. Intern. Med.. 25(3) 258. 

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