Liquid Forms of Naltrexone - Naltrexone Injection and Vivitrol
For patients who wish to avoid a surgical intervention for implantation, there is a liquid extended- release formulation of Naltrexone depot – Neltrexone injection injectable.
It is an oil salt solution of Naltrexone fatty acids which are released slowly into the blood stream. During the period of one month there is sufficient concentration of Naltrexone in blood serum providing the necessary protection from opiate drugs.
Naltrexone in oil is a transparent liquid. It is packed in the dark glass 10 ml vials.
Advantages of Naltrexone injection over Naltrexone implants:
No surgical intervention needed, which means:
- no need for licensed surgeon and a surgical hall
- no need for anesthesia
- no need for after surgery treatment: bandaging, removing the threads etc.
- no risk of septic complications due to the uncorrected after surgical treatment
- no foreign object under the skin
- no risk of rejection like in case of Naltrexone implant
- no scar
Disadvantage of Naltrexone in Oil:
- only one month duration of opioid blocking effect. You have to reinject Naltrexone injection on the monthly base.
What is Vivitrol?
Vivitrol has exactly the same effect like Naltrexone injection.
Alkermes Inc. USA developed a medication Vivitrol (Naltrexone for extended-release injectable suspension). Alkemeres Inc. had been working on new Naltrexone polymer formula for more than 10 years.
Vivitrol is an extended-release, microsphere formulation of naltrexone designed to be administered by intramuscular (IM) gluteal injection every 4 weeks or once a month. The injection must be administered using the safety needle supplied and the carton components provided. Vivitrol microspheres consist of a sterile, off-white to light tan powder that is available in a dosage strength of 380 mg naltrexone per vial. Naltrexone is incorporated in 75:25 polylactide-co-glycolide (PLG) at a concentration of 337 mg of naltrexone per gram of microspheres. The diluent is a clear, colorless solution. The composition of the diluent includes carboxymethylcellulose sodium salt, polysorbate 20, sodium chloride, and water for injection. The microspheres must be suspended in the diluent prior to injection.
