Antabuse (disulfiram) blocks the normal breakdown of alcohol in the body. When someone drinks alcohol while taking it, even small amounts, it causes a severe toxic reaction that can begin within 5–30 minutes and last for hours.

What happens:

The reaction is due to acetaldehyde buildup — a highly toxic substance. Typical effects include:

• Flushing, severe sweating, and throbbing headache

• Intense nausea and vomiting

• Chest pain and palpitations

• Rapid heartbeat and low blood pressure

• Difficulty breathing, confusion, and anxiety

• Blurred vision and weakness

In severe cases — especially after an entire bottle of wine — the reaction can cause:

• Dangerously low blood pressure

• Cardiac arrhythmias or heart attack

• Seizures

• Loss of consciousness

• Death, particularly in older adults or those with heart or liver problems

For a 63-year-old, this would almost certainly require immediate emergency medical attention (call 911).

(http://www.autoadmit.com/thread.php?thread_id=5787622&forum_id=2/en-en/#49358756)