<prompt> True statement regarding methadone are all except:It is a long acting mue-receptor agonistIt is rapidly absorbed from the gastrointestinal tract and is detected in plasma 30minutes after oral administrationsThe primary use of methadone is relief of chronic painThe onset of analgesia is 30-60 minutes after parenteral administration and 1-2 hours after oral administration  <response>: Ref: Goodman and Gilman 12th506-507 Methadone The onset of analgesia occurs 10-20 minutes after parenteral administration of methadone and 30-60 minutes after oral administration. It is well absorbed from the GI tract and can be detected in plasma within 30 minutes of oral ingestion. Primary uses are relief of chronic pain and in main tenance therapy of opioid addiction. 