Pentobarbital, also known as pentobarbitone, is a short-acting barbiturate. In high doses, pentobarbital causes death by respiratory arrest. In the United States, the drug has been used for executions of convicted criminals. Lundbeck (one of many manufacturers) does not permit its sale to prisons or corrections departments to carry out the death penalty. Abbott Pharmaceuticals‘ brand of pentobarbital, Nembutal, which was available in 50 and 100 mg yellow capsules, was discontinued in 1999. Prescribed for insomnia, it has been largely replaced by the benzodiazepine family of drugs. Nembutal was widely abused and known on the streets as “yellow jackets” due to their yellow capsule. Pentobarbital in pill form is no longer available. The death of Marilyn Monroe in 1962 was ruled as probable suicide due to an overdose of Nembutal. Kenneth Halliwell‘s death is also attributed to an overdose of Nembutal.