Friday, August 31, 2012

Rizzoli & Isles: Death by Drugs

I am a huge Rizzoli and Isles fan. I love both the TV show and the novels by Tess Gerritsen on which the show is based, even though the two are very different.

Anyone who's read Gerritsen's books knows that the producer made some big changes to the two main characters when the TV series went into production. Jane Rizzoli became a street savvy tomboy who eschews dresses and high heels for sweatsuits and gym shoes. Maura also changed into a wackier version of the brilliant pathologist portrayed in Gerritsen's books. Secondary characters were added or transformed in order to appeal to a broader based audience.

Until recently, I was pleased that the producer at least had the good sense to leave the science alone. Gerritsen is a master at writing realistic medical scenes and making sure Maura Isles is up-to-date on the scientific side of crime solving. There are no medical mistakes in Gerritsen's books.

But there sure was a big medical mistake in an episode of the TV program a few weeks ago. A wealthy young man wearing a mask and a cape died suddenly during a kinky sex party. During the autopsy, Maura discovered he'd been INJECTED with POTASSIUM CHLORIDE in an amount sufficient to cause a cardiac arrest. Rizzoli's investigation eventually led her to the wife of the dead man's partner. The police decided she was the logical killer mainly because she was a school nurse and thus had access to potassium chloride and how to inject it in order to kill someone.


I practically leaped out of my chair at the stupidity of that claim. The writers really got that wrong!

First of all, potassium chloride in its injectable form can only be bought if a veterinarian has prescribed it for use in the care of a sick animal and the individual buying it has a prescription signed by the vet. Even then there are difficulties getting it from an ordinary pharmacy. Generally one must buy such a product from a pet care company that deals in veterinary medicine.

Doctors DO NOT prescribe injectable KCl (potassium chloride) for use by non-medically trained individuals because of the extreme danger of death by overdose. Injectable KCl can only be found in hospitals where trained pharmacists dilute it in solutions of normal saline (NS) or 5% dextrose in water (D5W), or in other medical facilities equipped to administer IV potassium chloride in solutions.

Diluted KCl is given intravenously in varying amounts depending on the  need. Normal human potassium levels range from 3.5 to 5 mEq/L in the blood. If someone has a level lower than 3.5, that person is said to be suffering from hypokalemia. Mild to moderate hypokalemia can be treated with potassium in pill form. Severe hypokalemia, where the potassium level is less than 2.5 mEq/L, is generally treated intravenously using the following solutions: 10 mEq in 100 ml of solution; 20 mEq in 250 ml of solution; or 40 mEq in 500 ml of solution. Depending on the amount of KCl given, it will be infused over a span of one to four hours.

Why so slow when it comes to infusing KCl, you ask. Well, the truth is, the stuff hurts like heck if given too quickly. Patients will complain that the arm with the IV in it feels like it's on fire. If it hurts that much when diluted with saline or dextrose, just imagine how painful it would be if your imaginary killer injected straight undiluted potassium chloride into a victim's vein. Unless the injection was made in a vein close to the heart, the victim would have at least a few moments in which to scream.

How much KCl would it take to kill someone if it was injected undiluted into a vein? Now we're talking what's called LD50 -- the lethal dose for 50% of people weighing 75kg, or 165 lb. It's been estimated that the lethal IV dose of KCl is 30 mg per kg of body weight for a person weighing 75kg, and it has to be injected quickly.

So let's say your killer got his hands on a 10 ml (10cc) bottle containing the usual 2mEq/1ml of injectable KCl. That's 20 mEq KCl in a 10 ml bottle. He needs 30mg/kg, and his victim weighs 75 kg. Multiply 30 x 75 and you get 2250mg of KCl needed to send the victim's heart into an abnormal rhythm that would in all probability lead to a rapid death. 2mEq of KCl = 150 mg, so a 10 ml bottle would contain 1500 mg. Your killer would need to use at least 1 and 1/2 bottles -- or 15 ml (15cc) -- and would probably feel safer going with 20 ml (20cc), the entire contents of two bottle.

Now have you ever seen a 20cc syringe? They're not those little syringes used when you get a flu shot, or the even tinier ones used to administer insulin. They are BIG syringes, not easily hidden in your hand or your pocket. They're not the kind you can easily buy, either.

What I'm trying to say here is this: the SCHOOL NURSE in that episode of Rizzoli & Isles didn't have the ability to get her hands on injectable KCl. School nurses don't have access to that kind of drug, and she had no access to a hospital pharmacy. The only way she could have gotten it was through her pet's vet. But NO MENTION was ever made of her having a pet of any kind, healthy or sick, so forget the vet idea. And where did she get the 20cc syringe, and how did she hide it in the gauzy little outfit she was supposedly wearing when she killed the guy?

Writer mistake, for sure. Now if you're thinking of including a death-by-potassium-chloride scene in your book, remember what you read here and WRITE IT RIGHT!



  1. Thanks for the clarification. I usually just take it for granted the writers know what they are talking about. Course, I would have certainly run it by you first before including it in my book.

  2. And I would run any scene I wrote that included Native American spiritualism past you, Sandy. You're a research expert on that subject.

  3. I saw that episode and didn't even wonder. Like your first commenter, I assumed the writers knew what they were doing.

    Thank you for explaining this. Now I won't make the same mistake.

  4. I don't watch the show because I can't stand what they've done to two of my favorite series characters, but if I had I would have known *something* was wrong with that scenario. I wouldn't have known exactly what, though, so thank you for the explanation. And thanks for starting this great feature!

  5. Mary, I think most of us assume that TV writers do their research when scripting a series. Some times, though, they just don't get it right, and I wonder if it's because they're rehashing plots that worked in the past in other shows. The 'murder by potassium injection' thing has been done to death both on TV and in books and movies.

    Sandra, glad to see you here, and glad to know you enjoy The Writer's ER.