Naltrexone

Description

This is an antagonist that has the ability to evacuate and occupy the relevant receptor sites in the brain, it reverses the effects of opioids among dependent individuals. Naltrexone Hydrochloride is a non addictive substance with a variety of applications (such as an abstinence reinforcing agent in problem drinking), not to be confused with Naloxone, the emergency treatment for opioid overdose.

While some patients do well with the oral formulation, it must be taken daily, preferably supervised and a patient whose cravings become overwhelming can start using again simply by skipping a dose before resuming opiate use. Oral naltrexone in opioid dependence is limited by the low retention in treatment, despite its approval by NICE. Oral naltrexone is optimal among specific opioid-dependent populations, usually the ones with an unusually stable social situation and high motivation (e.g., dependent health care professionals). Naltrexone treats the physical dependence on opioids, but further psychosocial interventions (such as counselling and group therapy) are often required to enable people to maintain abstinence.

Rapid Antagonist Induction (RAI) or Ultra Rapid Opiate Detoxification (UROD) is an inpatient procedure currently unavailable on the NHS, that offers the most painless method for coming off opiates yet devised. In short, you are sedated with intravenous or oral anaesthesia and withdrawal is induced by an opiate antagonist (naloxone/ Narcan). Some premedication is taken 12 hours before admission. A range of further medications such as clonidine (a relative of lofexidine) and octreotide (an anti diarrhoea medication) are administered. Although patients are often disorientated on regaining consciousness, most can be discharged within 48 hours of admission, although some units retain patients for five days, only commencing Naltrexone, as ‘blocker’ on around day three.

It is usual for a range of take home medications to be distributed to a responsible carer. The problem with this is that Naltrexone is only available (i.e. licensed) as a tablet at the moment. While the technology for an implant and a depot injection exists, they are very difficult to access in the UK.