( CNN ) -- The U.S. Justice Department is reviewing a request from 13 states on how to acquire an execution drug no longer made in the United States and whether the federal government would share its supplies , a federal spokeswoman said Wednesday . The sole U.S. manufacturer of sodium thiopental , an anesthetic used as part of the lethal three-drug cocktail , announced last month that it would stop making the drug because the producer never intended it to be used to kill people . The U.S. shortage of sodium thiopental , also used as an anesthetic for brief surgical procedures , may force states to postpone executions and has forced them to look outside the country for a supply or come up with alternatives . Those substitutes have n't been without controversy . In December , Oklahoma used an anesthetic commonly used to euthanize animals to execute John David Duty for killing a cellmate . Additional controversy surfaced last week about the drug 's shortage when six death row inmates filed a federal lawsuit seeking to prevent the Food and Drug Administration from importing the drug , saying the imports may be unsafe . In a letter last month to U.S. Attorney General Eric Holder , the attorneys general in 13 states said injection is the execution method in the majority of states with a death penalty , and protocols in those states use sodium thiopental , `` an ultra-short-acting barbiturate . '' `` Sodium thiopental is in very short supply worldwide and , for various reasons , essentially unavailable on the open market , '' the letter said . `` For those jurisdictions that have the drug available , their supplies are very small -- measured in a handful of doses . The result is that many jurisdictions shortly will be unable to perform executions in cases where appeals have been exhausted and governors have signed death warrants . `` Therefore , we solicit your assistance in either identifying an appropriate source for sodium thiopental or making supplies held by the federal government available to the states , '' the letter said . Justice Department spokeswoman Alisa Finelli said Wednesday that federal officials have received the communication . `` We 'll review the letter , '' she said . Oregon is one of the 13 states signing the letter and has run out of the execution drug , said spokesman Tony Green of the Oregon Department of Justice . `` It 's pretty straightforward . We do n't have a supply of the drug so we 're looking for sources for them should we need them , '' Green said . Oregon , which has n't had an execution since 1997 , does n't have any lethal injections scheduled , though more than 30 men are on death row , he said . All those cases are in various stages of appeal , he said . The other states signing the letter are Alabama , Colorado , Delaware , Florida , Idaho , Mississippi , Missouri , Nevada , Tennessee , Utah , Washington and Wyoming . Texas , which was n't part of the letter , performs the most executions in the country and is also facing a shortage of the drug , said spokesman Jason Clark of the Texas Department of Criminal Justice . Texas has enough sodium thiopental to carry out this month 's two scheduled executions , on February 15 and February 22 , but the state 's stock of the drug will reach its expiration date in March , Clark said . Texas has executions scheduled in April , May and July , he said . `` The agency is exploring all of its options at this point , including seeking an alternative source of sodium thiopental as well as seeking an alternative drug to use in a lethal injection process , '' Clark said . Switching to an alternative drug could be done administratively , but switching to a different execution method would require legislative approval , Clark said . `` If we were to go to a firing squad , that would be a change in the execution method '' requiring lawmakers ' approval , Clark said . In their recently filed federal lawsuit , death row convicts are seeking an injunction barring future imports of the drug and removal of supplies of the drug already in possession of state governments . The lawsuit represents inmates in Arizona , California and Tennessee . The FDA continues to allow states to import `` bulk amounts '' of the drug for use in lethal injection without vetting it to ensure it meets regulatory standards , the lawsuit charges . `` The imported thiopental in question has not been listed with FDA , was manufactured by foreign companies that have not registered with FDA , and was exported by a wholesaler located in the United Kingdom , '' says the lawsuit , filed in U.S. District Court in the District of Columbia . `` FDA has not determined whether the thiopental being imported into the United States is safe and effective , whether the imported thiopental is adulterated or whether the imported thiopental is counterfeit , '' the suit says . An FDA spokesman declined to comment last week , citing the litigation .
Sodium thiopental is part of three - drug cocktail used in lethal injection . The U.S. manufacturer of the drug said last month it would stop making the drug . It states that using the drug in prison are asking feds if they will share their information . Meanwhile , six death row inmates are suing to stop imports they claim may be unsafe .