The opioid drug that addicts don't like could be approved next spring

An experimental drug from Nektar Therapeutics Inc. is heading into regulatory review — and abusers of pain-killing opioid drugs may not like it.

The oral drug, called NKTR-181, would be the first full mu-opioid — "mu" marking one of three receptors of powerful, addictive opioids — to be developed in more than 50 years