A multistate registry of pseudoephedrine sales that Oklahoma joined blocked up to 90,000 sales of the drug used to make methamphetamine last year, according to the Oklahoma Bureau of Narcotics.

Proponents of Oklahoma's decision to link its pseudoephedrine database with those in neighboring states say it restricts the interstate trafficking of the drug, which is found in many cold and allergy medications.

"They won't be able to just buy it here in Oklahoma, hit their daily limit, turn around and drive to Texas, Arkansas, Missouri or Kansas and do the same thing," said Mark Woodward, spokesman for the Oklahoma Bureau of Narcotics.

Authorities shut down 410 meth labs in the state in 2013, compared with 830 meth labs shut down in 2012, before the law went into effect, Oklahoma City television station KOKH reported (http://bit.ly/1fFRhZ7 ).