– Latin name is Digitalsi lanata
– Native to the Balkans
– A naturalised, invasive species in the US and Canada
– Contains a powerful cardiac glycoside called digitalin (or digoxin)
– Used in heart medication
– Adverse drug reactions common
– Margin between effectiveness and toxicity narrow
– Famously used in the Foxglove Murders and by Angel of Mercy killer, Charles Cullen
Foxglove (Digitalis lanata) contains digitalin (digoxin) which is a powerful cardiac glycoside historically used by those suffering heart conditions. Due to the small margin between its effectiveness and its toxicity, medical treatment for heart conditions is moving away from digitalin. Even so, more than 3 million prescriptions for it were issued in the US in 2017.
The effect of digitalin slows the heartbeat and slightly increases the contraction power, improving circulation. This has the flow on effect of better kidney function, which lowers the volume of blood and reduces the load on the heart. However, those exact benefits are also what makes digitalin potentially fatal, with toxicity symptoms of gastrointestinal distress, high potassium (kidney failure) and life-threatening heart arrhythmia and cardiac arrest.
The fine line between digitalin as a medicine and toxin has meant it’s been popular for homicidal purposes, as it is harder to detect.
Charles Cullen is an American angel of mercy serial killer who confessed to killing patients over 16 years as a nurse. Initially confessing to 40, it became apparent it was a much higher number, but while he could remember details of their murders, he rarely could remember their names. It’s been estimated by experts he may have been responsible for 400 deaths (which would make him the most prolific serial killer in recorded history). He was sentenced to 17 life sentences.
The Foxglove Murders were a series of murders committed by six young women from a Romany gypsy clan between mid-1980s to mid-1990s. All women married in May-December romances (marrying wealthy men in their 80s, while they were in their 20s). After the weddings, the men were killed with an overdose of digitalis heart medication with the women inheriting. Unfortunately, because of problems with the forensic evidence, the women weren’t charged with murder, but faced charges of conspiracy to murder, theft, embezzlement, fraud and forgery, which could carry life sentences (but the outcome of the trial doesn’t seem to have been reported).