A Warning about Milk Thistle and Drug Interactions

[Snowflake]

A Warning about Milk Thistle and Drug Interactions

The seeds of the milk thistle plant are commonly used to protect the liver from damage caused by hepatitis viruses as well as alcohol and other substances. Compounds found in milk thistle - sylibin, sylimarin - act as antioxidants and also stimulate the repair of the liver. But now it appears that these and possibly other compounds in milk thistle can have other effects.

Researchers at the University of Pittsburgh have suspected that milk thistle can slow down or reduce the activity of enzymes in the liver. What does this have to do with HIV? you might ask. Well, enzymes in the liver break down many of the substances that we eat and drink, including medications. If the activity of these enzymes are reduced, then drugs remain in the blood longer than they otherwise might. This could lead to having higher-than-expected levels of drugs in the body, causing side effects or intensifying already-existing side effects. Indeed, in recent experiments using milk thistle and human liver cells, the researchers found that relatively small concentrations of milk thistle did significantly slow down the activity of the liver enzyme CYP3A4 by 50% to 100%.

Many medications taken by people with HIV/AIDS (PHAs) - such as protease inhibitors and non-nukes - are processed by this liver enzyme. If milk thistle is taken by someone using protease inhibitors or non-nukes, it has the potential to raise levels of these drugs, causing unpleasant or even dangerous side effects. Below is a short list of some other medications that are processed through the CYP3A4 enzyme. Levels of these medications may increase if taken by people who are also using milk thistle. This list is not exhaustive:

methadone
heart drugs - Tambocor (flecainide), Rythmol (propafenone)
antibiotics - erythromycin, rifampin
anti-seizure drugs - carbamazepine (Tegretol)
antidepressants - St. John's wort, Zyban/Wellbutrin (bupropion), Paxil (paroxetine), Prozac (fluoxetine), Luvox (fluvoxetine) Serzone (nefazodone), Zoloft (sertraline), Effexor (venlafaxine)
antihistamines - Hismanal (astemizole), Seldane (terfenadine)
antifungals - itraconazole (Sporanox), Ketoconazole (Nizoral)
gastrointestinal motility agents - Prepulsid (Cisapride)
ergot drugs - Ergonovine, Ergomar (ergotamine)
anti-psychotics - Clozaril (clozapine), Orap (pimozide)
sedatives/sleeping pills - Ambien (zolpidem), Halcion (triazolam), Versed (midazolam)
lipid-lowering drugs (statins) - Lescol (fluvastatin), Mevacor (lovastatin), Pravachol (pravastatin) and Zocor (simvastatin), Baycol (cerivastatin)
transplant drugs - cyclosporine (Neoral, Sandimmune), ProGraf (tacrolimus)

Milk thistle also has the potential to lower levels of the following drugs:

anti-parasite drugs - Mepron (atovaquone)
sedatives/sleeping pills - Ativan (lorazepam)
hormones - estrogen

The research by the scientists in Pittsburgh should emphasize to readers that simply because a product is "natural" it does not mean it is safe when taken with other substances. This research also shows the need to conduct further research on herb-drug interactions on liver cells as well as in people. Such studies may find combinations of herbs and drugs that can be safely used together.

The Pittsburgh researchers noted that "patients and health care professionals must be encouraged to discuss the use of herbs and be educated about the potential interactions between herbs and drugs." This cannot be stressed enough.

REFERENCE

Venkataramanan R, Ramachandran V, Komoroski BJ, et al. Milk thistle, a herbal supplement, decreases the activity of CYP3A4 and uridine diphosphoglucuronosyl transferase in human hepatocyte cultures. Drug Metabolism and Disposition 2000;28(11):1270-1273.

This information was provided by the Community AIDS Treatment Information Exchange (CATIE). For more information, contact CATIE at 1-800-263-1638.

For more information chekc out our Herbal Glossary , and also check out our CAM information (Complementary and Alternative Medicine) on our FactSheet page

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[jody13]

Snowflake, it is amazing to me that ama or the universitys wants to warn you about herbs but says nothing about satin drugs, some people take several of them at once, given by the doctors.  People are dying a slow death while on these cure all pills. I'll stick to my herbs.   jody

[DougV]

Jody,

They really aren't warning about herbs at all, but rather warning of a potential interaction.  There is also some thought that milk thistle can interfer with the absorption of RIBA by the liver.  Doesn't mean it is bad, just that it should not be combined with certain pharmacuticals.  There are several herbs and even a ton of pharmacuticals that on the own are not harmful and may even be helpful, but those in combination with other drugs can cause issues.  Grapefruit is known to interact negatively with several drugs.  Grapefruit itself is good for you, but don't drink it if you are going to take it with things it does not go with.  Somethings gotta give you know.

But you gotta wonder, who comes up with some of these rules and why.  Take grapefruit and many cholesterol drugs.  They aren't supposed to go together.  But what about lemons, citron, limes, key lime pie, oranges, tangerines, etc. etc..  Why just grapefruit? 

Doug

[Snowflake]

Hello,

jody, I understand your frustration with doctors prescribing so many meds out. I feel the same in alot of ways, but i also think people need to educate themselves on what they are about to take. And see if there is something they can do though diet and exercize.
I also feel herbs are meds and should be taken with care. Some herbs can build up in the body and become toxic. I don't know of any herb that should be taken for over six months. Without break periods of several weeks, most should only be taken for acouple of months at a time. Your body even needs a break from regular vitamins.
I know really very little about this all, except one thing moderation...

Doug, You hit the nail on the head, it is a warning... My GI told me while on TX not to take Milk Thistle and other herbs as it may interfer. As well as with my test results. I posted an artical in Transplant Forum, warning of jucies and it seems grapefruit is not alone. They have found that Orange and Apple jucies, may limit absorption also. They give a list of meds...

TAKE CARE
 Winona

[Frank310_9]

perhaps milk thistle is wat i need> im told my liver enzymes are very high