DENVER (AP) -- Access to a powerful drug that can stop drug overdoses could be expanded in Colorado.

The state Senate begins work Thursday on a bill to expand access to so-called "opioid antagonists," injected or inhaled drugs that can stop an opiate overdose by "freezing" the brain's receptors for opiates such as heroin or OxyContin. The drugs temporarily restore normal breathing so that overdosing addicts can be taken to a hospital. The drugs are commonly sold under the generic name naloxone.

Naloxone counteracts the effects of heroin, OxyContin and other powerful painkillers and has been routinely used by ambulance crews and emergency rooms in the U.S. for decades. The Colorado bill would allow more people to use naloxone on people in an overdose.