What is the duration of action for Methadone once administered?

The correct choice indicates that the duration of action for Methadone is approximately 24 hours, which reflects its profile as a long-acting opioid agonist. Methadone is primarily used for the treatment of opioid dependence and pain management. Its long half-life allows for once-daily dosing in many patients, providing a stable plasma concentration that can effectively manage withdrawal symptoms and cravings in individuals with opioid use disorder.

This prolonged effect is significant because it helps to decrease the potential for misuse and provides a controlled means of managing both pain and dependence. Methadone acts on the same receptors as other opioids, but due to its lengthy duration of action, it can help prevent the peaks and troughs associated with shorter-acting opioids, contributing to better overall stability for patients.

Other durations provided in the options do not accurately capture Methadone's pharmacokinetic profile; the shorter durations do not align with how Methadone functions within the body. The striking contrast between 1-2 hours or 3-5 hours versus the 24-hour duration underscores the importance of understanding the pharmacological classifications of medications, especially in populations managing chronic pain or in opioid recovery programs.