After IM injection, the naltrexone plasma concentration time profile is characterized by a VIVITROL (naltrexone for extended-release injectable).Br J Psychiatry. 2009;194(6 541546. PubMed 38. Waal H, Frogopsahl G, Olsen L, Christophersen AS, Mrland J. Naltrexone implants: duration, tolerability and clinical usefulness; a pilot study. Eur.
How it works: Reduces brain levels of the neurotransmitter dopamine (which is believed to create the pleasurable sensations alcoholics get from drinking potentially resetting the brain s chemistry Side effects: Numbness and tingling in the hands and feet, difficulty concentrating, confusion, nervousness, headache, drowsiness and.