Milk Thistle Cautions
There have been occasional reports of the seeds causing bloating or diarrhea or having a laxative effect.
Milk thistle can cause some gastrointestinal side effects in some people, including:
- Nausea
- Diarrhea
- Bloating
- Gastroenteritis
- Loss of appetite
If you are currently being treated with any of the following medications, you should not use milk thistle without first talking to your healthcare provider.
- Antipsychotics -- includes butyrophenones (such as haloperidol) and phenothiazines (such as chlorpromazine, fluphenazine, and promethazine)
- Phenytoin -- a medication used for seizures
- Halothane -- a medication used during general anesthesia
- Cytochrome P450 3A4 substrates: Milk thistle inhibits cytochrome P450 3A4 and can affect the intracellular concentration of drugs metabolized by this enzyme. However, conflicting data indicate no such effects . In another study, consumption of milk thistle did not reduce levels of indinavir, an AIDS drug . UGT (Uridine 5’-diphospho-glucuronosyltransferase) substrates: Milk thistle modulates UGT enzymes in vitro and can increase the side effects of drugs metabolized by them .
Sirolimus: Milk thistle may decrease clearance. Monitor therapy especially when combined with nivolumab, which may interfere with the potential to help prevent rejection of donor kidney in transplant patients .
Haloperidol or Risperidone: 7 cases of pancreatitis were reported following concomitant use of milk thistle
Aripiprazole: A case of hepatotoxicity was reported with combined use
of milk thistle
High doses of silibinin can elevate bilirubin and liver enzymes
Milk thistle may interfere with the following medications, because both milk thistle and these medications are broken down by the same liver enzymes:
- Allergy drugs -- such as fexofenadine (Allegra)
- Drugs for high cholesterol -- such as lovastatin (Mevacor, Altocor)
- Anti-anxiety drugs -- including alprazolam (Xanax), diazepam (Valium), and lorazepam (Ativan)
- Antiplatelet and anticoagulant drugs (blood thinners) -- including clopidogrel (Plavix) and warfarin (Coumadin)
- Some cancer drugs
An adverse reaction to the herbal medication milk thistle (Silybum marianum).