Friday, January 16, 2009

St. John's Wort and Drug Interactions

There are few interactions between botanical products and pharmaceuticals, but one herbal product has developed a nasty reputation for this problem. That product is St. John's Wort. Today's blog is a recap of the known interactions that this herb has with pharmaceutical products.

Take note of these. The list below comes from an article published in Current Drug Metabolism from 2008. See my suggestion at the end of this blog for a substitute product.

1) Anticancer Drugs: Imatinib and Irinotecan. Patients taking these drugs along with SJW are recommended to avoid the herb.

2) Anticoagulants: Warfarin, acenocoumarol, phenprocoumon, etc. These drugs can potentially be severly affected by SJW.

3) Anticonvulsants: Do not take SJW with drugs such as phenytoin.

4) Antidepressants: This article suggests that SJW not be taken with Amitriptyline.

5) Antifungal agents: Voriconazole was affected significantly by SJW.

6) Antihistamine: Fexofenadine as one example. Not recommended with SJW.

7) Anti-HIV agents: Such as indinavir, lamivudine, and nevirapine . . . can result in drug resistance and treatment failure when combined with SJW.

8) Antihypertension (Blood pressure meds): SJW is not recommended with drugs such as verapamil, nifedipine, or talinolol.

9) Benzodiazepines: Questionable in combination with SJW.

10) Bronchodilators: Doses of Theophylline had to be increased if patient was on SJW.

11) Cardiac Gluycoside: Digoxin efficiency was reduced with multiple doses of SJW.

12) Cholesterol lowering drugs (Statins): SJW interacts and appears to decrease the effect of the drug.

13) Hypoglycemic agents: This article recommends that doctors and patients should closely monitor the reduced efficacy of these drugs if taking SJW.

14) Immunosuppressants: Patients with organ transplants or on immunosuppressants should not take SJW.

15) Methadone: Addicts taking methadone and SJW would sometimes resume illicit drug use due to decreased effect of methadone when combined with the St. Johns Wort.

16) Oral Contraceptives: Patients taking birth control pills should be warned against possible consequences of taking SJW.

17) Protein Pump Inhibitors: Omeprazole dosage should be increased if taking SJW, or patient warned of interactions causing less efficacy.

18) Serotonin Re-Uptake Inhibitors (SRI's): Antidepressants that are affected by SJW. The authors state that these drugs should not be combined with SJW, with possible exaggerated serotonin effects.

19) Selective Sinus Node Channel Inhibitor: Ivabradine and SJW are a bad combination.

It is clear that St. John's Wort is a unique botanical, and that the potential for interaction with pharmaceuticals is significant. I'd suggest that you try Rhodiola rosea, which has an even stronger mood support function than SJW, and which many people are now using to replace SJW when an herb is used in conjunction with a pharmaceutical product. Rhodiola has centuries of use in Scandinavia and other cold regions where it is taken as a daily tonic. Use the search function on this site for "Rhodiola" to read previous articles about that herb.



Patricia C. said...

Dave - Appreciate this post. I've used SJW successfully, but have also investigated other options due to its potential interaction with birth control pills. Will have to check out Rhodiola.

It's hard to find such a comprehensive list of potential interactions. Great info and very important for people to know.

Dave Jensen said...

Thanks Patricia . . . Rhodiola has been used for centuries, and has been studied now for four or five decades scientifically. There are no drug interactions with the product. See references on this blog and others to Rhodiola rosea - BUT be cautious, never buy a cheazy store brand. Most health food stores sell only brands that do not have efficacy.