Toxic Fungi of Western North America

by Thomas J. Duffy, MD

Disulfiram-like reactions to alcohol

Coprinopsis (Coprinus) atramentaria, whose gills deliquesce to a black ink to spread its spores, are the common cause of this syndrome. Coprinopsis insignis is an Eastern species with the same toxins, but a few sightings have been reported from Western North America. These inky caps in the former Coprinus genus contain a protoxin “coprine” which is converted to 1-aminocyclopropanol-- a compound with an antabuse-like reaction with alcohol.

Coprine
Fig. 11. Coprine

Antabuse® is used as an adjunct in the treatment of alcoholics. This compound prevents the normal breakdown of alcohol to carbon dioxide and water. It inhibits the enzyme aldehyde dehydrogenase and the excess acetaldehyde causes flushing, throbbing in the temples and usually headache starting 5-30 minutes after ingestion of alcohol.

Acetaldehyde pathway
Fig. 12. Acetaldehyde pathway from alcohol to acetic acid

Other symptoms may include nausea, sweating and occasional diarrhea. The normal pathway is shown below, but disulfiram type reactions are blocked to a major extent at acetaldehyde and do not go on to acetic acid and CO2.

Because of a very thin, tightly adhering veil, Coprinopsis atramentaria has a white cap when very young. The caps rapidly become gray or gray brown, marshmallow-shaped, conical to ellipsoid, then finally campanulate. The young still closed ovoid-elliptical mushrooms have caps 3-7 cm X 2.5-5 cm; the campanulate caps may measure up to 9.5 cm across. The moist caps are finely grooved and decorated with flat grayish scales mostly at the center; the caps may be almost smooth in contrast to many species of the Coprinus group. The crowded gills are first white, then grayish brown; finally becoming black as they begin to deliquesce. The stipe is 6-14 cm long and 7-14 mm thick, white with a slightly clubbed base, sometimes slightly rimmed.

Coprinopsis atramentaria
Coprinopsis atramentaria photo © Tom Duffy

A Coprinopsis atramentaria meal ingested with alcohol (or minutes to 8 hours after the alcohol) most commonly sets off the syndrome 3-15 minutes later. Much longer periods for symptoms to appear with Coprinopsis meals following alcohol have been reported. The usual recurrence period is given as up to 48 hours later. The author and his wife had a lunch-time reaction with beer after an earlier Coprinopsis atramentaria breakfast. We tried the same amount of beer with lunch again at 24, 48 and 72 hours after the initial symptoms and both of us had recurrent, but progressively milder symptoms each time. Both of us had freely ingested Coprinopsis atramentaria in the past with alcohol and had had no symptoms previously, a not uncommon report.

Clitocybe clavipes (= Ampulloclitocybe clavipes), with a wide distribution from Mexico to Canada, produces a similar syndrome. (183,184) Similar symptoms, but usually with more of a GI component, have also been reported with Pholiota squarrosa, Boletus luridus and Boletus pulcherrimus. These mushrooms have little in common and other toxins are likely.

Ampulloclitocy<em></em>be clavipes
Ampulloclitocybe clavipes photo © Michael Wood

It is best to avoid therapeutic interventions. The symptoms are usually transient. Vital signs should be monitored until symptoms have subsided and the blood pressure is stable. Some of the symptoms are caused or worsened by panic and it is very important that the patient understand the expected benign course. By 45 minutes, the episode is usually over. Occasionally, symptoms persist for 2-3 hours.

However, there have been a few severe poisonings requiring monitoring for cardiac arrhythmias. For an extremely rapid heart rate, beta blockers such as propanolol have been suggested. (185) A 53 year old man with unusually severe vomiting had a fatal rupture of the esophagus—a dreadful emergency which requires immediate surgery. (186) Experimental animals have shown testicular abnormalities, but even if that damage could be translated to humans, over a pound a day of Coprinopsis atramentaria for a week would be needed to replicate loss of sperm production! (187)