Opioids misuse

Something of a stereotype now follows, but in a good cause to illustrate some practical points in management of minor opioid misuse. I would contend that there is a syndrome of a classic case of someone who becomes dependent on paracetamol and codeine combinations, or dihydrocodeine, dextropropoxyphene or something similar, with the following features ... 

Efforts are put into preventing minor opioid misuse, both in primary care policies and in pharmacy schemes to reduce inappropriate sale of over-the-counter products (McBride et al. 2003). In treatment, this is an example of a population usually disinclined to take... 

The association between methadone treatment and QTC interval prolongation, QRS widening, and bradycardia has been explored prospectively in 160 patients with at least a 1-year history of opioid misuse (19). The QTC interval increased significantly from baseline at 6 months (n = 149) and 12 months (n = 108). The QRS duration and heart rate did not change. There were no cases of torsade de pointes, cardiac dysrhythmias, syncope, or sudden death. There was a positive correlation between methadone concentration and the QTC interval. 

The antitussive effects of opioids occur both centrally and peripherally. Mu-receptors [24] in the brainstem cough center and in the sensory arm of the vagus nerve, which controls airway reflexes, appear to mediate this effect. The weak analgesia associated with codeine makes it a good choice as an antitussive and it has frequently been used as a component of cough syrups. These cough syrups are sold over-the-counter in some areas and have been a source of opioid misuse and diversion. Codeine is not an active antitussive in young children and has potential for respiratory suppression in this patient populatiOTi for that reason, it is not recommended for children [25]. 

There is some evidence of a synergistic effect on reinforcement with concurrent administration of benzodiazepines and opioids (Walker and Ettenberg 2003). Cocaine abusers are less likely than opioid abusers to abuse benzodiazepines, preferring alcohol and opioids as secondary drugs of abuse. The most common pattern of benzodiazepine misuse in these individuals is intermittent use of therapeutic or supratherapeutic doses to counter unwanted effects of cocaine. 

Oxycodone can be abused in a manner similar to other opioid agonists, legal or illicit. Consider this when prescribing or dispensing oxycodone CR tablets in situations where there is concern about an increased risk of misuse, abuse, or diversion. 

Individuals who have been misusing pharmaceutical opioids pose a particular problem, as any straight conversion from claimed average usage tends to result in methadone dosages which appear excessively high. In practice, such users can usually be given doses of... 

As mentioned earlier in the chapter, in the UK lofexidine is far more frequently selected in opiate detoxification than clonidine because of its better safety for outpatients, and a large comparative study of this and buprenorphine was carried out by Raistrick et al. (2005). Two hundred and ten patients were randomized, and the same comparisons in standard drug misuse outcomes and satisfaction measures were also studied in 271 individuals who did not wish to be in the randomized study. Many outcomes were similar with the two medications, but 65% of buprenorphine patients completed detoxification against 46% of those on lofexidine. That study was an example of one which included a follow-up to see whether patients had been abstinent after detoxification, with this being the case at the measurement point of one month for 38% of lofexidine completers and 46% with buprenorphine. This important aspect of whether successful detoxification does indeed lead to further abstinence has attracted attention in several buprenorphine studies, as reviewed by Horspool et al. (2008). Across five qualifying studies, they found detoxification completion rates of 65 to 100%, but low rates of abstinence at follow-up points, with more patients having returned to opioid maintenance than had complied with naltrexone. 

This book is mainly concerned with the treatment of opiate misuse, for the simple reason that that is the form of drug misuse for which there are the most effective clinical approaches. As we have discussed, the treatment scene for opiate misusers, in contrast to other groups, is fundamentally altered by the widespread availability of the substitution option, in the form of methadone or alternative opioids. Physical dependence is part of the rationale for that approach, and the occurrence of clear-cut withdrawal symptoms also indicates the use of drugs such as lofexidine or clonidine, followed where possible by naltrexone. For reasons of severity of dependence and treatment options, it is therefore understandable that services are inclined to have caseloads dominated by opiate users. 

Diconal) Opioid medication, highly regarded by drug misusers... 

Although many of the problems related to drug misuse are personal and social as well as medical and legal, current treatment responses have been strongly influenced by the historical emphasis on opioids in drug legislation to the detriment of a naturally evolving and wider multidisciplinary treatment and rehabilitation service. 

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