Crime Division: Medications as a Murder Weapon (in Fiction writing, Of Course) Joynell Schultz, PharmD, RPh

Hmmm… You have someone to kill. You need a creative way, and the old-fashioned gun, knife, rope, or Pillow Suffocation simply won’t do. Using a medication sounds intriguing. In the alphabet soup of drugs, which one makes the perfect instrument of death?

You sit in front of your laptop, staring at a blank page writing the perfect murder mystery with a medication as the murder weapon. Where do you begin? Here’s a quick guide to those considerations.

Lethal Dose

The lethal dose is how much medication is needed to cause enough damage for someone to die. Hey, the last thing you want is to not give enough, and the victim lives to tell the tale. Especially if they know or suspect the culprit.

Talk to any health care provider that works in the emergency room and they’ll have stories about people attempting to commit suicide. “I took a handful.” Well, how much is that? Many times, a handful isn’t quite enough, depending on how toxic the mediation is. A simple Google search of whichever medication you’re looking at and “toxic dose” will get you in the ballpark.

Onset of Action and Timing

Another thing to contemplate is how fast do you want the victim to die. Do they need to die immediately, in just enough time for the killer to get across the city, or sometime way later, when the perpetrator is (conveniently) on vacation in Hawaii?

This is a balancing act between the dosage form of the medication and how it creates toxicity in the body. We’ll start with dosage form. Here’s a list from the quickest route of absorption to the slowest. Keep in mind, some medications don’t work certain ways. For example: drinking insulin won’t do anything.

  • Injection
  • Oral formulations (knowing a liquid or immediate release tablet will work quicker than a long acting or delayed released product.)
  • Topical — Though, there are exceptions to this rule. Some medications, like nitroglycerin or fentanyl, are absorbed quickly through the skin inside your mouth. An interesting suggestion I’ve been giving is putting a medication powder in somebody’s shoes. I struggle with this one. For enough medication to get absorbed through someone’s socked foot and thick soles of their feet may make this nearly impossible.

The other component is how long it takes for the medication to affect the target organ system. Opioids, insulin, and cardiac medications tend to be quick acting, as they directly affect the end organs, where medications you give due to their toxic principals, like acetaminophen or warfarin, will take longer.

Primary versus Secondary Cause of Death

Do you want the victim to die from the medication itself (as a poisoning), from a side effect of the medication (like liver failure), or from a secondary cause of death as described below.

  • Examples:
    • The boy working the drive through at the local coffee shop doesn’t like his school principal. He slips some of his dad’s calcium channel blocker pills into the principal’s coffee. While driving home from the coffee shop, the principal blacks out from low blood pressure and crashes the car.
    • Your ex-girlfriend, yeah, the one who broke your heart, swims in the ocean every morning. While she’s slipping into her bikini, you slip a dose of a neuromuscular blocker into her water bottle. Typically, these are injected, but the lipid-soluble ones like physostigmine can be absorbed through the GI track. She takes a big sip and jumps into the ocean. Half-way into her exercise routine, her muscles lock up and she drowns.
    • Wife gives her husband a few sleep aides to get a good night sleep, diphenhydramine or a benzodiazepine for example, then set’s the house on fire. Husband doesn’t get out alive.

Victim Experience

  • How much do you want the victim to suffer? Do you want a long agonizing, painful death or short and quick?
    • Tylenol overdose is a good example of a long and painful death. Besides the nausea and vomiting, the brain swells and organs shut down—slowly and uncomfortably.
    • An overdose of an opioid or other sedative would have your character meeting a quick demise.


  • Do you want your killer to get caught, or not? Do you want to blame someone else with access to the medication for the crime? Do you want it to show up on a routine toxicology screen?
  • In my opinion, the best methods are those medications that are found naturally in your body.
    • Insulin. Everybody’s pancreas produces insulin. People have normal swings of this secretion—even if you’re not diabetic. In fact, a high fat meal can cause a substantial insulin dump and can trigger hypoglycemia in a non-diabetic. (Especially if paired with no carbohydrates.) A small shot of insulin, in a location difficult to identify in an autopsy, can trigger hypoglycemia and death.
    • Electrolytes are another good example.
      • Potassium: Your body needs it to survive. If a person has too much potassium, their heart rhythms get off. Too much potassium in a single injected shot will stop the heart.
      • Sodium: Yeah, we’re talking table salt here. A shot of strong salt water will rapidly cause rapid nerve damage. Drinking a large quantity of salt will do the same.
  • Another thing to consider is the victim’s underlying conditions. Can you exacerbate something they have? A non-selective beta blocker in an asthmatic. A penicillin in an allergic patient. Trigger hypoglycemia in a diabetic. Intentional self-inflicted overdose in person with a history of depression? A drug-food or drug-drug interaction with a patient on warfarin.


  • The last consideration is how easy is it to obtain the medication, and if you obtain it, can it be traced back to you?
  • Over-the-counter medications are great due to their accessibility, but the toxic doses of them are high compared to some prescription drugs.
  • Illegal street drugs are another thing you probably could obtain by asking a few questions to some shady characters. A dose of heroin would EASILY take care of your character.
  • Then there are prescription drugs. Is there a family member you can steal from? Does your character work in a hospital? Pharmacy? Or did they recently visit Mexico where they can purchase prescription medications over-the-counter? Another option is to look into the veterinary world. Many items can be purchased for farm use without a prescription.

Using medications can be a fun way to kill someone (in your novel, of course.) At the very least, it’s intriguing to think about. I’m signing off, as I’ve thoroughly freaked my husband out now.  There are a hundred more details we could discuss, but that’s for another day.

Happy writing.


Our thanks to Joynell Schultz for this fascinating look at medications and options for upping your killer’s game.


Joynell Schultz’s passion for writing was overshadowed by obtaining a doctorate degree in pharmacy from the University of Wisconsin – Madison, a “reliable profession.” After spending countless hours working in pharmacy management, Joynell traded it in for a simpler life. She now works part-time as a veterinary pharmacist, which pays the bills and gives her enough time to create alternative worlds writing speculative fiction.

While shivering through the long northern Wisconsin winters with her husband, two children, and numerous pets, she enjoys reading, writing, and planning her next vacation.

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Joynell’s novel, Love, Lies & Clones, is available now on Amazon here:

20 thoughts on “Crime Division: Medications as a Murder Weapon (in Fiction writing, Of Course) Joynell Schultz, PharmD, RPh

  1. This is great information! Shared with my writing group. I know one mistake I see a lot of writers make is that they have every drug showing up in a routine toxicology exam. If writers are going to use a drug as a cause of death they should contact a toxicologist to find out if it would show up in a routine test or if additional testing is required and what information is needed for the toxicologist to know to test for it.

    1. That is an excellent point. A routine tox screen only tests for common medications. You need a special reference lab to detect other ones…and you need to know what meds you want tested for. It really complicates the matter. Thanks for the comment!

  2. interesting info I did find it a little comical, especially the example about the ex-girlfreind that broke your heart.. ha ha

  3. Interesting stuff! I hadn’t really thought much about this…but that’s really cool! And also slightly creepy how easy it might be to kill someone with medication and then blame it on someone else.

      1. Exactly! You’d never know if it was a murder or just some sad accident…and it would be really hard to find evidence to convict the culprit.

  4. Oh my god, wow! I guess I’d never really considered this 😮 all my books are full of paranormal creatures, so naturally I automatically write brutal murders, but…. this is such a good idea

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