Pfizer says it's blocking use of drugs for lethal injections

The development means the approximately 25 FDA-approved companies worldwide able to manufacture drugs used in executions have now blocked the use of the drugs, according to Reprieve, a New York-based human rights organization opposed to the death penalty.

"Pfizer's actions cement the pharmaceutical industry's opposition to the misuse of medicines," Maya Foia, Reprieve director, said in a statement.

[...] as recently as last year, records showed that labels of Arkansas execution drugs appeared to indicate that the state's potassium chloride, which stops the heart, was made by Hospira.

Texas, with the country's busiest death chamber, obtains its pentobarbital for lethal injections from a supplier the state identifies only as a licensed compounding pharmacy.

Texas is fighting a lawsuit trying to force it to identify drugmakers from April 2014, when attorneys unsuccessfully filed appeals to stop two executions by seeking the identity of the drug providers, and September 2015, when the state's secrecy law took effect.

Last year, Utah approved the use of firing squads for executions if drugs aren't available, while Oklahoma became the first state to approve nitrogen gas for executions if lethal injection drugs become unavailable or are deemed unconstitutional.