Final answer:
Naloxone (Narcan) should be immediately available for emergency use when a woman receives narcotics during labor to reverse the effects of opioids and prevent respiratory depression.
Step-by-step explanation:
The drug that should be immediately available for emergency use when a woman receives narcotics during labor is Naloxone (Narcan). Naloxone is an opioid antagonist that can reverse the effects of opioids, including respiratory depression. It rapidly precipitates withdrawal in narcotic-dependent individuals. Naloxone is used to reverse the respiratory depression that follows acute narcotic intoxication and the narcotic-induced respiratory depression in newborns of mothers who have received narcotics.