• Open Access

The risks of diverted take-home methadone


Correspondence to:
Dr Steven McGloughlin, Infectious Diseases Registrar, Prince Charles Hospital, Chermside Qld. Fax: (07) 4050 6854; e-mail: smcgloughlin@rfdsqld.com.au

Methadone maintenance programs have been successfully used in Australia since 1969, with many beneficial effects. There is, however, potential for diversion of prescribed oral methadone and intravenous injection of ‘take-home’ treatment doses. This case demonstrates a potentially catastrophic complication of the injection of methadone and a description of an unusual method of seeking a microbiological diagnosis in a critically ill patient.

A 63-year-old Caucasian man presented through the Emergency Department (ED) complaining of abdominal pain, vomiting, fever and headache with an associated acute onset of confusion and agitation. The patient's past medical history included substantial intravenous drug abuse with methamphetamine, heroin, cocaine and methadone. He was treated empirically with antibiotics including 2 g Ceftriaxone and 500 mg Metronidazole intravenously for potential sepsis of abdominal origin.

Over the subsequent two hours his condition deteriorated and he required intubation and transfer to the intensive care unit where his antibiotic regime was changed to Vancomycin 1 g bd, Ticarcillin and Clavulanate 3.1 g qid and Fluconazole 400 mg daily. After discussion with his wife it was revealed that during the afternoon the patient had prepared and injected 40 mL of Methadone syrup prescribed to his wife, which had been diluted by the pharmacist with tap water, for un-supervised oral consumption at home. She reported her husband used a “new sealed bottle and new needle”.

In an effort to obtain a causative organism and target treatment the methadone bottle and syringe were cultured. Both specimen cultures grew Enterobacter cloacae and Stenotrophomonas maltophilia and his antibiotic regime was rationalised based on this information. Blood culture specimens from the patient were negative but this was confounded by collection post antibiotic administration. The patient's clinical condition improved and he was discharged home on day nine.

Methadone has been used to treat heroin addiction in Australia since 1969 and it continues to be a major component of a harm minimisation strategy for effective management of heroin addiction.1 The use of methadone has been shown to reduce criminal behaviour, HIV infection rates, injection-related risk taking behaviour and illicit opioid use.2 Methadone maintenance treatment involves the daily consumption of a prescribed dose of methadone. In many cases patients are prescribed take home doses to be consumed away from the prescribing clinic. In Queensland, in order to be considered for take-home doses the patient must demonstrate stability over several months, which is rewarded by an increased frequency of allowed take-home doses.3 Take-home doses are considered by clients to contribute to satisfactorily meeting employment and family responsibilities.4 The take-home doses are usually diluted in an attempt to reduce the likelihood of diversion and injection of methadone.3

Take-home methadone can be used for intravenous injection or procured by other users either by gift, stealing or street sale.4 A study of methadone injectors in Sydney revealed that respondents believed that injection of methadone provided quicker and more effective relief of symptoms and they enjoyed the ‘rush’ provided by the injection.5 The frequency of methadone injection in Australia is difficult to quantify, in South Australia, 18.4% of 365 current heroin users reported having ever injected methadone,6 while in Sydney between 1996 and 2000, 43% of 788 interviewed injecting drug users had injected methadone.7

The injection of methadone requires dilution due to the thickness of the oral methadone syrup, which is concentrated at 5 mg per mL. Injectors therefore require a dilutant as well as large barrel syringes or multiple injections via small barrel syringes. Patients who inject it have been shown to be in poorer general health then non injectors.8 In this case the methadone was provided from the registered supplier diluted in tap water. In some Australian regions methadone is provided diluted with a liquid containing particulate matter such as orange juice to reduce the viability of injection.4 Methadone injectors are known to have an increased rate of both systemic and skin infections.8

While the injection of methadone is well-documented among those on the methadone maintenance program this case highlights the risk of significant complications associated with this practice. The use of take-home medications has obvious benefits for both the patient and the dispenser. However, there must be ongoing recognition that patients and other members of the community will inject methadone and that this has potentially severe complications. Therefore, methods to deliver methadone in a safe manner for patients and other members of the community need to be continually re-evaluated, such as dispensers considering the provision of sterile water with take-home methadone doses. This may reduce the risk of potentially catastrophic bacterial infections, in this particular patient group, but needs to be balanced against any possible increase in methadone injection rates.