There are two main objectives of specialist opiate detoxification techniques: to reduce the duration of detoxification whilst minimising discomfort to the patient and to induct the patient onto naltrexone at the earliest possible opportunity. It is hypothesised that the combination of these factors will enhance both patient up-take and the immediate and longer term outcomes of detoxification. The various techniques vary in their use of either a general anaesthetic or heavy sedation, and in the timing of opiate-antagonist administration. Specialist services should provide access to some forms of rapid opiate detoxification for selected cases.

ULTRA-RAPID OPIATE DETOXIFICATION

Ultra-rapid detoxification is an umbrella term that has come to represent a new treatment approach specifically designed to detoxify patients within hours rather than days and to almost completely eliminate the subjective discomfort of withdrawal symptoms. These factors lead directly to enhanced up-take of detoxification by clients and a more rapid induction onto naltrexone than can be achieved with traditional detoxification. The essential components of this technique are the administration of large doses of opiate antagonists (naloxone, naltrexone or nalmefene) leading to rapid reversal of opiate receptor down-regulation, together with a general anaesthetic. Naloxone is the most commonly used antagonist for this purpose (with or without naltrexone in addition), and naltrexone is continued orally following completion of the detoxification to prevent relapse. Adjunctive medication is used to control various withdrawal symptoms including metoclopramide for vomiting, ranitidine as a gastro-protectant and octreotide as an anti-diarrhoeal. Detoxification using such techniques may be completed within as little as 4 to 6 hours, allowing employed patients to return to work the following day, and can usually be performed on a day-patient basis.

The major risk associated with ultra-rapid detoxification is the risk associated with administration of a general anaesthetic. The risk of death having received a general anaesthetic for any purpose is in the region of 1 in 250,000 and of adverse events 1 in 10,000 (D'Ambra, 1998). However, the mortality rate may be as high as 1 in 1000 for the ultra-rapid detoxification procedures which have been carried out world-wide to date. The risk of adverse events in this client population may be increased by the increased prevalence of thyroid dysfunction in habitual opiate users. There are also two case reports indicating a possible risk of cardiovascular morbidity in patients receiving high dose naloxone under general anaesthetic (Taft R, 1983) (Andree M, 1980). All clients should be assessed by an anaesthetist before acceptance for treatment, and those with evidence of cardiovascular, thyroid or hepatic dysfunction will usually be excluded.

RAPID OPIATE DETOXIFICATION

Rapid detoxification also involves the use of naloxone and/or naltrexone to speed the withdrawal process. In contrast to ultra-rapid detoxification a general anaesthetic is not used; rather the discomfort of withdrawal is ameliorated by the use of a central adrenergic agonist (usually clonidine) and generous doses of sedative medication (usually benzodiazepines) rather than anaesthesia. Doses of opiate antagonist are smaller than those used in ultra-rapid detoxification, and the duration of detoxification varies from between 2 and 12 days, depending on the particular protocol used (O'Connor & Kosten, 1998). The use of heavy sedation is usually considered to require admission to a high dependency unit (risk of accidental self-injury and aspiration of vomitus), although some regimes have been designed to limit the amount of sedation required, even to the extent of the procedure occurring on a daypatient basis (see below).

A recent Italian study (Gerra et al, 2000) compared three forms of day-patient detoxification. Patients were randomised to one of three groups which received either a standard methadone detoxification over 10 days, a standard adrenergic agonist detoxification for 5 days or a rapid opiate detoxification over 2 days. The rapid technique appeared to have various advantages.

• Withdrawal symptoms were much more severe and prolonged in the methadone treated group as compared to the other two groups.
• Both negative and positive craving scores were much more severe and prolonged in the methadone treated group as compared to the other two groups.
• Mood was significantly lowered after detoxification in the methadone treated group as compared to the other two groups, although this difference resolved within weeks.
• Use of heroin was significantly lower during detoxification in the rapid detox group as compared to the other two groups.
• Acceptance and commencement of postdetoxification naltrexone therapy (75% of subjects) was significantly greater in the rapid detoxification group than in the other two groups.
• Relapse to heroin dependence at 6 months was significantly lower in those that initially accepted naltrexone therapy than those who refused it.

NALTREXONE COMPRESSED OPIATE DETOXIFICATION (NCOD)

A well-known current example of this procedure in the UK is carried out in the Detox 5 group of centres. The regime differs from rapid detoxification in that adrenergic agonists are not routinely used, sedation levels are lower and naltrexone is administered for the first time on day 4 of the 5 day detoxification period.