On Wednesday, the United States Supreme Court will review Oklahoma’s three-drug execution protocol. The primary question posed by Glossip v. Gross is whether the use of midazolam as the first drug violates the Eighth Amendment, which prohibits cruel and unusual punishment, by creating a substantial risk of serious harm to condemned prisoners. The Court’s past decisions make clear that an execution procedure violates the Constitution if it presents, to quote the majority opinion in Baze v. Rees, “‘objectively intolerable risk of harm' that prevents prison officials from pleading that they were subjectively blameless for purposes of the Eighth Amendment.”

There should be no doubt in this case: As used in Oklahoma’s execution procedure, midazolam unquestionably creates an “objectively intolerable risk of harm.” Because it is not capable of functioning as a general anesthetic, midazolam provides no relief from searing pain; but, that is exactly what it is expected to do in executions in Oklahoma, Florida, and other states.

Oklahoma executes prisoners by administering midazolam first, followed by a paralytic drug and then potassium chloride. The second drug paralyzes the voluntary muscles, preventing all movement (including facial expressions) and stopping respiration. The third drug, concentrated potassium chloride, stops the heart. In the doses used in executions, potassium chloride has been described as “liquid fire” because without anesthesia it causes intense burning pain upon entering the veins. Midazolam’s role in the execution is to anesthetize the prisoners so that they are unaware of the paralysis caused by the second drug and insensate to the burning pain caused by the third.

Midazolam is a benzodiazepine drug. Its primary clinical use is to provide anxiolysis, amnesia, and sedation. It is not used clinically to induce the type of deep, general anesthesia needed to withstand painful stimuli, and we have good reason to doubt that midazolam, regardless of the size of the dose administered, can reliably produce the “deep comalike unconsciousness” that is necessary to prevent the unconstitutional pain and suffering caused by the potassium chloride in a three-drug lethal injection execution.

Glossip v. Gross will be the second time in seven years that the Court has reviewed a three-drug, lethal injection procedure. In Baze v. Rees (2008), the Court approved Kentucky’s three-drug execution procedure, which was then-used by at least 30 states. In the intervening years, the second and third drugs used in three-drug procedures have remained largely the same.

The significant difference between the procedure approved by the Court in Baze and the protocol currently facing scrutiny is the first drug. In the old procedure, Kentucky first administered a barbiturate, sodium thiopental, to produce a “deep comalike unconsciousness,” thereby preventing the terror and extreme pain that would otherwise be caused by the subsequent drugs. Barbiturates, when used correctly, induce a deep general anesthesia in which patients do not feel pain. The Court in Baze acknowledged that, without a “proper dose of [the barbiturate] that would render the prisoner unconscious,” the protocol would be unconstitutional. But the Court found that Kentucky’s procedure included adequate safeguards to ensure delivery of a proper dose of the sodium thiopental and therefore upheld the procedure.

Unlike barbiturates, benzodiazepines do not induce deep general anesthesia. For this reason, Oklahoma’s use of midazolam creates an intolerable risk that prisoners will not be sufficiently anesthetized to withstand the pain caused by the rest of the process. Similar to the procedure described in Baze, a member of Oklahoma’s execution team examines the prisoner to determine unconsciousness following administration of midazolam. But that safeguard is inadequate when using midazolam as the first drug. The searing pain from the potassium chloride is far more stimulating than the check for unconsciousness, so although the prisoner appears to be “asleep,” the effects of potassium chloride are sufficiently noxious to break through the midazolam-induced sedation.

Yet the prisoner’s experience will be invisible. After the paralyzing drug has been administered, the prisoner will be incapable of demonstrating the extreme pain caused by potassium chloride. He will appear serene. The harm goes unrecognized, and the protocol goes unchanged, putting future prisoners at risk.

Whether it is rational or ethical to have capital punishment is a question for a different day. Permitting preordained, unnecessary, and excruciating pain and suffering—based on the use of a drug that cannot perform as needed to protect against the harm that the next two drugs unquestionably will cause—assaults prisoners’ dignity and demeans us all. It's also unconstitutional.