The next step in this situation should be to administer Naloxone (Narcan). Naloxone is an opioid antagonist, meaning that it can counteract the effects of opioids. Overdose on opioids can cause respiratory depression, which can lead to decreased breathing and decreased oxygenation of the body's tissues.
Naloxone works by binding to the same receptors in the brain that opioids bind to, thereby reversing the effects of the opioids and restoring normal breathing. Naloxone is a fast-acting medication that can quickly reverse the effects of an opioid overdose, and it is often used in emergency situations to save the life of someone who has overdosed.
Buprenorphine and methadone are both opioids used to treat opioid addiction, while naltrexone is also an opioid antagonist like naloxone, but it is used for the treatment of opioid addiction, rather than for emergency reversal of opioid overdose.