Centrifugation: When plasma is required, or when not using a serum gel separator tube, follow these instructions: 1  Draw 12 mL of whole blood for each 5 mL of serum or plasma needed. 2  Centrifuge for at least 15 minutes at 2200-2500 RPM. 3  Pipette the serum or plasma into a clean plastic screw-cap vial and attach the label.
Buccal administration; Naloxone; Naltrexone; opioid antagonist; Pharmacokinetics; First-pass metabolism Summary The opioid antagonists naloxone and naltrexone are both known to undergo extensive first-pass metabolism after oral dosing. The buccal route was investigated as a potential alternative to oral administration. Oral and buccal bioavailabilities of naloxone and naltrexone were determined in rats. Less than 1 % of oral naloxone or naltrexone was bioavailable, but buccal administration resulted in approximately 70% bioavailability for each drug.
The use of naltrexone was first approved for the treatment of opiate dependence in 1984 and for alcohol dependence in 1994. In 2006, Vivitrol, a new formulation of this medication was approved for alcohol and in 2010 Vivitrol was approved for the prevention of relapse to opiate dependence.Naltrexone does not cause an antabuse-like aversion reaction.ates of nausea and GI symptoms are lower when using Vivitrol compared to oral naltrexone. Soreness at the injection site is common and can be managed with massage, NSAIDS, or ice packs. This is a similar side effect to other IM buttocks injections, such as antibiotics, and is not related to naltrexone itself.