Details About Overdose or Poisoning Generic Salt :: Silymarin Or Milk Thistle, Silybum Marianum
Silymarin or Milk Thistle (Silybum Marianum)
Drug Pharmacology ::
I. Pharmacology. Extractsof the milk thistle plant have been used since ancient times to treat avariety of liver and gallbladder diseases, including cholestasis,jaundice, cirrhosis, acute and chronic hepatitis, and primarymalignancies, and to protect the liver against toxin-induced injury.The extract of the ripe seeds and leaves contains 70–80% of the activeflavonoid silymarin, which is composed chiefly of silybin A and B. Thehypothesized mechanism of action of silymarin, supported by in vitroand animal studies, is twofold: alteration of hepatocyte cell membranepermeability, preventing toxin penetration, and increased ribosomalprotein synthesis, promoting hepatocyte regeneration. Although theefficacy of milk thistle for toxin-induced liver injury in humans hasnot been established clearly, it has been associated with reduced liverdamage when administered within 48 hours of Amanita phalloides ingestion. Competitive inhibition of A. phalloidestoxin receptor binding has been demonstrated. One study also showedpreservation of hepatic glutathione stores in rats exposed to highlevels of acetaminophen.
Silymarin also is reported to have antifibrotic, anti-inflammatory, andantioxidant activity and may have therapeutic efficacy in the treatmentof prostate and skin cancer. There is preliminary evidence that milkthistle constituents may also protect against the nephrotoxic effectsof drugs such as acetaminophen, cisplatin, and vincristine.
Drug Indications ::
Indications. Unproven but possibly effective as adjuvant therapy in cases of acute hepatic injury caused by Amanita phalloidesmushroom ingestion, acetaminophen toxicity, and potentially otherchemical and drug-induced liver diseases. Silymarin is available in theUnited States and Europe as a parenteral drug, and milk thistleextracts can also be purchased as over-the-counter dietary supplementsfor oral use.
Drug Contra-Indications ::
III. Contraindications. None reported.
Drug Adverse Effects ::
IV. Adverse effects are few and generally mild.
Nausea, diarrhea, abdominal fullness or pain, flatulence, and anorexia may occur.
Milk thistle is a member of the Asteraceae(daisy) family and can cause an allergic reaction in ragweed-sensitiveindividuals, including rash, urticaria, pruritus, and anaphylaxis.
Use in pregnancy. FDA category B. Insufficient reliable information is available (see Table III–1).
Drug Lab Interactions ::
Drug or laboratory interactions.Although milk thistle has been shown to induce slight cytochrome P-450enzyme inhibition in vitro, significant drug interactions with milkthistle extract have not been demonstrated in humans.
Drug Dose Management ::
Dosage and method of administration
Oraldoses used in published studies have ranged from 280 to 800 mg/day ofstandardized silymarin. A typical dose used for toxic hepatitis is 420mg/day in two or three oral doses.
Intravenous dosing for Amanita phalloidesmushroom poisoning is 20–50 mg/kg over 24 hours divided into fourinfusions. Each intravenous dose is administered over 2 hours.
Drug Chemical Formulations ::
Formulations
Oral. Inthe United States, milk thistle extract is available as anonprescription dietary supplement (eg, Thisilyn). Oral pharmaceuticalformulations available in Europe include Legalon (standardized tocontain 70% silymarin) and Silibide (isolated silibinin complexed withphosphatidylcholine). Because silymarin is poorly water soluble, milkthistle tea is not considered an effective preparation.
Parenteral. An injectable preparation of 50 mg/mL silymarin is now available in the United States (Apothecare 1-800-969-6601).
