Drugs are designed to cure illnesses, but at times they can also become
instruments of death. And historically, many drugs originated as botanicals. Even today, many drugs and their active ingredients come from plant sources.
Awhile back, I came across an interesting report that described a drug from plant origin that can both cure and kill. As I read the article describing what is being developed from the sap of the oleander plant, I remembered what my mother used to tell me. “Stay away from the oleander. It’s poison!”
The oleander plant (Nerium oleander) is a common shrub found in warm Southern climates. It grows as tall as twelve feet and produces beautiful, fragrant, colorful blossoms.
Oleander is indeed a poisonous plant. The milky sap from the leaves and stems contain oleandrin, a powerful cardiac glycoside so toxic that ingesting one leaf has been reported to kill a small child. Although documentation is poor regarding the exact toxicity of the sap, it’s been estimated that ingesting 15-20 leaves would kill a normal adult (Yes, I also wonder who would enjoy a lunch of oleander leaves).
Symptoms of an overdose include gastrointestinal (nausea, vomiting, diarrhea), cardiac (interestingly, both lethal slowing and rapid increases in heart rates) and neurological (tremors, loss of muscle control, seizures).
Accidental poisoning from oleandrin ingestion can be deadly and articles are published so that physicians have established medical protocols to deal with such potentially lethal poisoning.
On the other hand, oleandrin—when properly prepared as a drug—has been used 
beneficially for years. In Russia and China, it is used to treat congestive heart failure and cardiac arrhythmias. An interesting tidbit is that it is also a popular method of suicide in both of those countries. Such actions are also becoming a growing concern in Sri Lanka.
Presently, oleandrin is being studied as a promising anti-cancer treatment. Patented drug extracts are being investigated at the Memorial Sloan Kettering Cancer Center for various innovative treatments of cancers. Other studies have investigated the cytotoxic properties of oleandrin for treating melanomas.
As I’ve read about these new drug developments, I thought about how drugs have been used throughout the ages to cure and kill. Ancient alchemy, as a precursor to modern pharmacology, produced wonderful life-saving medicines while at the same time spawning lethal poisons for primitive weapons such as darts and arrows.
Modern pharmacology has furthered this balance of curative and lethal science in much the same way—so many ways to heal, and yet so many methods to kill. I find it especially interesting that many modern drugs have a narrow therapeutic window in that a small amount of drug is good, but a little more can be deadly.
As a writer, that gives me a multitude of plot ideas. How about you? Happy writing!
Thoughts? Comments? I’d love to hear them!
Prescription For Murder 
Nothing like a nice oleander salad, eh? The balance between good and bad in plants that can kill is pretty common in nature I suppose. Some metaphorical to that I guess. There is a plethora of good plot ideas related to the plant as well as some possibly good titles.
Arlee Bird
A to Z Challenge Co-host
Tossing It Out
All the best to you, Arlee Bird. Will post more lethal botanicals in the near future for more plot ideas.
Ah yes the ol’ narrow therapeutic window. Few people understand this concept. For most Americans, “chemicals” are either good or bad. They’re poisons or cures. Hard to accept that they are both.
On that note, you must check out http://www.dhmo.org/
That reminds me, Amy, that I should add something about narrow therapeutic windows in one of my stories. Thanks for the interesting link. All the best!
It would make for a fragrant demise . . .
🙂
Its me again!
I keep coming back to find more poisons for my story. This time a man is found dead by one of the protagonists doorstep and she needs to figure out which poison was used to kill him. I’ve planned for it to be Oleander but I was wondering if there were more symptoms (like rashes, hives ect) that would help determine what they were poisoned with. (Like, I’m not sure you’d be able to tell they had -for example- blurred vision before they died unless someone was with them and said ‘They said they felt sick and their vision was blurry’ and sucha such)
I will probably be back since the killer is turning into a serial killer and I need about 4 more botanical poisons
Hi Emily:
That’s good to try for extra details as clues of what poison killed your character. Yes, oleander can produce a topical reaction in those allergic to the plant. This is an interesting article that gives examples: http://www.livestrong.com/article/550107-allergic-reactions-to-oleanders/
Thanks for your interest and keep writing your story. It sounds fascinating.
hi James J. Murray
kill by The oleander plant can found by Forensic medicine or blood test?
Thanks for your readership and your question!
Yes, to a certain extent a blood test would show digoxin/Oleandin elevated blood levels to indicate oleander plant poisoning, but forensics would also substantiate that with leaf evidence in the digestive tract, oleandrin levels in the urine, liver and the heart since it is a cardiac glycoside.