Warning - taking Fenbendazole and paracetamol? (acetaminophen)

Hi all,

This was something I only recently became aware of so though i should share it.

Key Findings from Research :https://pmc.ncbi.nlm.nih.gov/articles/PMC3262853/

Animal Study Evidence: A 2011 study in mice found that pretreatment with fenbendazole (at doses equivalent to 8–12 mg/kg/day for 7 days) significantly worsened acetaminophen-induced liver damage.

Specifically:Acetaminophen alone caused centrilobular hepatic necrosis and elevated liver enzymes (ALT/AST) within 12 hours.When combined with fenbendazole, the damage was more extensive, with greater necrosis, higher enzyme levels, and 63% mortality within 24 hours.Fenbendazole alone did not cause liver issues.The mechanism appears to involve prolonged depletion of glutathione (GSH), a key antioxidant that detoxifies acetaminophen's toxic metabolite (NAPQI). Fenbendazole delayed GSH recovery without altering acetaminophen's metabolism or major cytochrome P450 enzymes (except a minor suppression of CYP1A2).This interaction was investigated because fenbendazole is commonly used in lab rodents, and it highlights a potential drug-drug effect in hepatotoxicity models.

Human Relevance: There are no published clinical trials or case reports confirming this interaction in humans. Fenbendazole is not FDA-approved for human use (it's a veterinary dewormer), so data is limited to off-label contexts like experimental cancer protocols. Both drugs are metabolized in the liver via the cytochrome P450 system, which could theoretically lead to similar risks, such as altered drug clearance or compounded stress on liver function. Sites promoting fenbendazole use (e.g., for alternative therapies) note this as a speculative concern and recommend monitoring liver enzymes (ALT/AST) if combining them, along with liver-supportive supplements like milk thistle.

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