The drugs used in lethal injections were not designed to kill people, and they are on the market today because of their use in medicine. Pharma companies don't allow them to be used for executions, but Arkansas got their hands on some anyway. Here's what the three drugs in the US state's lethal injection cocktail actually do.
Illustration by Jim Cooke
Lethal injections have become rare, in part because pharma companies don't want to aid in executions and have blocked the sale of their drugs for that purpose. But corrections officers in Arkansas have managed to get their hands on three drugs that courts have ruled are suitable for the job. They have to hurry, though, because one of them expires at the end of this month. They planned eight executions, and four were allowed to go forward. The last of the four is scheduled for today.
Midazolam Is a Sedative
Midazolam, the drug whose expiration date is setting the schedule for Arkansas's executions, is a sedative. An anaesthesiologist might give a patient some when they get a colonoscopy, or as they're heading into surgery so they don't get nervous about everything else that's going to happen. It doesn't put the patient to sleep, but they might feel sleepy as a side effect, and they probably won't remember anything that happens while the drug is in effect. In surgeries, the patient gets midazolam first, and then the anaesthetic afterwards.
In Arkansas's lethal injections, midazolam is the first of the three drugs injected. Its dose is far higher than what a surgery patient receives -- 500mg instead of four. The idea is to relax the inmate, and perhaps make them unaware of what is going on. But it doesn't necessarily knock the prisoner unconscious or relieve pain. Two other drugs, thiopental or pentobarbital, are able to do that, but corrections departments have a hard time acquiring them any more. Midazolam is being used in their place.
Midazolam has been blamed for several botched executions, where the person being executed wasn't completely anaesthetised. After one of those, a 2014 execution that took nearly two hours, Arizona agreed never to use the drug in lethal injections again. Other states still use it, though, and the Supreme Court upheld its legality in an Oklahoma case as a lethal injection drug.
Vecuronium Bromide Causes Paralysis
Like midazolam, vecuronium bromide is commonly used in surgeries. It relaxes and paralyses muscles, so that the patient can't move. With a large enough dose, it can stop a person's diaphragm from moving, which means they can't breathe.
In a lethal injection, this drug is given at 100mg, far more than the eight or so milligrams given in surgery. The idea is to stop the prisoner from breathing. But because it paralyses muscles, the person would not be able to move or speak to express that they are in pain. So this drug, if effective, can have the effect of hiding whether the prisoner is suffering.
Potassium Chloride Stops the Heart
Potassium chloride is most often used in medicine as a simple way to supply potassium. Potassium is an electrolyte that we need for normal body functions; it's an ingredient in Gatorade and is the reason people tout coconut water as a great drink to hydrate you during or after exercise.
Because tiny amounts of potassium are involved in the way nerves and muscles work, a large dose of potassium can interfere with basic body functions. Most importantly, potassium chloride can stop the heart.
The drug is normally given in small doses over the course of a day, with a maximum daily dose of 200 milliequivalents. Arkansas's protocol gives the inmate 240 milliequivalents in a single dose. If the vecuronium bromide did its job, the inmate will already by dead by the time this drug is administered. But if not, it's extremely painful, with an anaesthesiologist testifying that it is caustic enough to destroy the person's veins. Even at normal doses, patients complain of a burning feeling.
These drugs aren't tested or approved for killing people, so there is no guarantee that they do so humanely. US states have had to tinker with their execution protocols, and often halt executions for years at a time, because they cannot obtain the drugs they want. Pentobarbital, used for euthanising pets, was once the standard for lethal injection but it has recently been impossible for US corrections departments to obtain.
None of the drugs' makers will sell their products to be used in executions, so corrections departments have to find sneaky ways of obtaining them (and typically try not to reveal their suppliers). Besides manufacturers' and sellers' restrictions, the European Union also prohibits export of any drugs that will be used as instruments of torture, which they define to include executions.
The drugs in Arkansas's cocktail are still on the market, though, because of their routine use in medicine. All three are on the World Health Organisation's list of essential medicines. The state managed to obtain all three in violation of the drugs' sellers' policies, and some of those companies filed briefs in court; but the executions are going forward anyway.