Orpheus in the Undergrowth - S2-E2
Corrected entry: Rosemary finds a bottle of Betabuse in Marcia's medicine cabinet. Betabuse, Rosemary tells Laura, is for alcoholics, who, while taking Betabuse and alcohol will throw up. Eventually, the alcoholic learns to equate drinking with vomiting. Jeremy, Marcia's husband and the alcoholic, is found dead from a heart attack. Marcia is arrested for killing him, because she (1) made him mushroom soup, using smooth ink cap mushrooms, which have the same ingredients as Betabuse, then (2) replaced the water from his water bottle as he went jogging with vodka. The police say Marcia hoped that when he took a swig of water and got Vodka instead, after eating the soup, it triggered a heart attack - now, yes, Jeremy had a "dodgy ticker", but throwing up is a far cry from dying from a heart attack.
Correction: This is a real thing and not exaggerated. The drug "disulfiram" does cause a reaction to alcohol consumption such as vomiting and nausea and used for chronic alcoholics. However, disulfiriam has been known to cause myocardial infractions (heart attacks). This is simply what happened to Jeremy.
Bishop73