The Tennessee Supreme Court unanimously rejected claims Monday that the three-drug combination used to execute killers can cause extreme pain in violation on the Constitution's ban on cruel and unusual punishment.

Lawyers for Abu-Ali Abdur'Rahman (search), who was sentenced to die by lethal injection for the 1986 beating death of a Nashville drug dealer, sought to change the state's death penalty method. Separate appeals to block his execution are pending in federal court.

Like many states, Tennessee uses a three-drug mixture in lethal injections. First, an anesthetic puts the inmate to sleep. The second drug, Pavulon (search), paralyzes the muscle system, and the third, potassium chloride, stops the heart.

The inmate's lawyers argued that the anesthetic could fail to work, and the Pavulon could then mask the signs, leaving the inmate in extreme pain, without the ability to cry out.

Lawyers for the state of Tennessee said that inmates are unconscious in seconds and die painlessly within five minutes.

The procedure has been used only once in Tennessee, when Robert Glen Coe (search) was executed in 2000. It was the state's first execution in 45 years.

Of the 38 states that have death penalty statutes, lethal injection is an option in every one except Nebraska.

A similar case is pending before the Kentucky Supreme Court, and doctors questioned the use of Pavulon earlier this year when Connecticut performed the first execution in New England in 45 years.