Doctors must lead us out of our opioid abuse epidemic

By Dr. Sanjay Gupta, Chief Medical Correspondent Veteran doctors don't need a blood test to tell when someone is on the verge of a drug overdose. They can even narrow down the culprit by observation alone. Dilated pupils mean cocaine, amphetamines, maybe LSD. Constricted pupils mean an opiate. Additionally, an opiate abuser is characteristically "nodding …