Final answer:
Narcan is not the only opioid antagonist. Naltrexone, Methadone, and Buprenorphine are also opioid antagonists used in different scenarios to alleviate symptoms of opiate withdrawal and maintain individuals on chronic therapy.
Step-by-step explanation:
Narcan (naloxone) is not the only opioid antagonist. Another opioid antagonist is Naltrexone, which is similar to Narcan but has a longer duration of action and can be taken orally. It is often used in narcotic treatment programs to maintain individuals on chronic therapy with a narcotic antagonist.
There are also other opioid antagonists such as Methadone and Buprenorphine, which are used to alleviate symptoms of opiate withdrawal.
So while Narcan is an opioid antagonist, it is not the only one available.