🍺 Coprine — The “Disulfiram‑like” Mushroom Toxin

Summary: Coprine is a toxin found in certain inky cap mushrooms that causes a disulfiram‑like reaction when alcohol is consumed. On its own, coprine is only mildly toxic, but in combination with alcohol it can trigger severe symptoms. This article covers the chemistry, occurrence, mechanism of action, symptoms, diagnosis, treatment, prevention, and practical advice for foragers.

1. Introduction

Coprine became well‑known because of its unique interaction with alcohol. People who eat coprine‑containing mushrooms and drink alcohol soon afterward develop unpleasant — and sometimes dangerous — reactions. This effect mimics that of disulfiram (Antabuse®), a medication used to deter alcohol consumption.

2. Chemistry & Properties

• Coprine is metabolized into an active compound (1‑aminocyclopropanol or related derivatives).

• This metabolite inhibits acetaldehyde dehydrogenase (ALDH).

• Consequence: accumulation of acetaldehyde, a toxic intermediate in alcohol metabolism, leading to the symptoms of poisoning.

3. Which Mushrooms Contain Coprine?

Coprine is primarily found in inky caps (formerly Coprinus, now reclassified into several genera):

• Common Ink Cap — Coprinopsis atramentaria (the classic cause of coprine reactions)

• Shaggy Mane / Lawyer’s Wig — Coprinus comatus — considered edible when young and fresh, and usually does not cause coprine reactions; however, confusion with other inky caps is possible.

• Other inky caps (Coprinellus, Coprinopsis) may contain related compounds but are less well documented.

4. Mechanism of Action

• Coprine’s metabolite blocks acetaldehyde dehydrogenase (ALDH).

• When alcohol is consumed, acetaldehyde cannot be converted to acetic acid efficiently.

• Acetaldehyde buildup triggers: facial flushing, nausea, palpitations, vomiting, sweating, headache, and in severe cases hypotension or shock.

• Symptoms typically appear 5–30 minutes after drinking alcohol following mushroom ingestion.

5. Clinical Symptoms

• Without alcohol: usually mild gastrointestinal upset, if any.

• With alcohol: classic disulfiram‑like reaction:

  • Flushing of the face and upper body

  • Palpitations (tachycardia)

  • Headache, dizziness

  • Nausea, vomiting

  • Sweating

  • Low blood pressure in severe cases

  • Rarely: collapse or loss of consciousness in individuals with underlying health issues

Onset: 5–30 minutes after alcohol consumption.Duration: several hours, depending on alcohol amount and metabolism.

6. Diagnosis

• Key clue: history of eating inky caps, followed by alcohol use.

• Physical exam: flushing, tachycardia, nausea.

• Lab tests: non‑specific; acetaldehyde levels can be measured in research settings but rarely in clinical practice.

• Helpful: photos or samples of mushrooms for accurate identification.

7. Treatment & Management

• Immediate care: monitoring of vital signs; ensure safety during vomiting (aspiration risk).

• Activated charcoal/gastric lavage only if very soon after ingestion and under medical supervision.

• Supportive treatment: IV fluids, antiemetics for nausea, benzodiazepines for agitation.

• No specific antidote exists.

• Avoid alcohol for at least 48–72 hours after consuming inky caps (some experts recommend up to a week).

8. Prognosis

• Generally good if alcohol is avoided.

• Severe complications are rare but may occur in people with heart disease or those who consume large amounts of alcohol.

9. Prevention & Foraging Advice

• Do not eat Common Ink Caps (Coprinopsis atramentaria).

• Only consume mushrooms you can identify with absolute certainty.

• If you’ve eaten inky caps, avoid alcohol for at least 2–3 days (better: a full week).

• Remember: alcohol is not just in beverages but also in sauces, medications, and mouthwashes.

10. FAQ

Is Shaggy Mane (Coprinus comatus) safe?Yes, when young and fresh it is generally considered edible and does not cause coprine reactions. Still, confusion with Common Ink Cap is possible.

How long should I avoid alcohol after eating inky caps?At least 48–72 hours, ideally up to one week.

Can coprine be deadly?Rarely. Deaths are extremely unusual. Danger arises mostly from cardiovascular collapse or accidents during severe reactions.

11. Conclusion

Coprine is not a classic deadly mushroom toxin but is dangerous in combination with alcohol. The most notorious species is the Common Ink Cap (Coprinopsis atramentaria). Prevention is simple: if you eat inky caps, avoid alcohol completely for several days.

Disclaimer: This article is for informational purposes only and not a substitute for professional medical advice. In suspected mushroom poisoning, seek emergency medical care immediately.