CELDAS DE COMBUSTIBLE
8.2.6. Celda de combustible de óxidos sólidossólidos
Pharmaceutical Care Research Group, Pharmaceutical Sciences, University of Basel, Switzerland
Project report based on the Master’s thesis by Fabienne Suppiger, supervised by Prof. Kurt E. Hersbergera, Dr. Kenneth Dürstelerb, and Samuel Allemanna
a Pharmaceutical Care Research Group, Pharmaceutical Sciences, University of Basel,
Switzerland
Project C2 | Medication profiles of substituted patients with opioid dependence syndrome: A longitudinal observational study
88
Abstract
Background: Opioid-assisted treatment (OAT) is the preferred treatment for opioid-
dependent patients. OAT is provided in controlled settings to approximately 19’400 of the 22’000-27’000 opioid-dependent patients in Switzerland. Thanks to the success of OAT, life expectancy for opioid-dependent patients improved greatly. Recently, sustained-release Morphine has gained interest for OAT. Similarly, Methylphenidate, approved for the
treatment in attention deficit hyperactivity disorder, has been considered for substitution of Cocaine dependency. The prevalence of the use of these substances and other medications in an ageing population remains unclear.
Objectives: An outpatient addiction service (OAS) provides OAT and other medications to
opioid-dependent patients in Basel (Switzerland) and records all dispensing events in an electronic database. This study is a first-time retrospective analysis of the patient collective, the drug prescriptions and dispensing practice at the OAS in Basel.
Methods: We performed a longitudinal observational study with historical data recorded
between 2002 and 2013 at the OAS in Basel. We analyzed demographic properties, general information about medications, information about opioid substitution treatment, and Information about treatment with methylphenidate. We applied Mann-Whitney U-Test for comparisons of two independent groups, Wilcoxon signed-rank test for paired groups, and linear regression to estimate trends.
Results: Between 2002 and 2013, the number of patients increased from 112 to 154. Mean
age rose from 37.1 to 45.0 years. Alongside, the number of active ingredients per patient increased from 2.71 to 3.55 per year. Most substances were used in the therapeutic area of the nervous system, which includes all substitution medications and methylphenidate preparations. Methadone remained the predominant substance for OAT, but its use declined by 25%. Most of this proportion was replaced by sustained-release Morphine preparations. Methylphenidate prescriptions declined from 21.4% in 2002 to 16.9% in 2013. Short-acting preparations were fully replaced by long-acting formulations.
Conclusion: Treatment facilities providing OAT must accommodate their setting for older
patients with polypharmacy. A more diverse selection of different treatments increases the complexity of pharmacotherapy and requires close collaboration of different healthcare providers.
Project C2 | Medication profiles of substituted patients with opioid dependence syndrome: A longitudinal observational study
89
Introduction
Between 0.1% and 0.7% of the population in Western Europe are affected by a problematic opioid use178. While the number of new opioid-dependent patients in Switzerland declined
sharply in the past two decades, the prevalence of opioid-dependence remained stable179.
This can be explained by the medicalization of the problem, its recognition as a chronic condition, and the success of opioid-assisted treatment (OAT). In 2010, an estimated 22’000 to 27’000 people in Switzerland were opioid-dependent and roughly 19’400 received OAT. Over 90% were treated with Methadone, around 8% with Diacetylmorphine (Heroine), 5% with Buprenorphine, and 1% with other opioids, such as sustained-release Morphine180. Due
to its long half-life, methadone is considered the gold standard for OAT. However, its side effects and serious interactions with other medications pose limitations for its use. Recently, sustained-release morphine preparations have gained interest for use in OAT181. Long-term
OAT has been shown to reduce various risks associated with illicit drug use, including infectious diseases, overdoses, premature deaths, disability, crime, prostitution, and social isolation182. As a result, life expectancy for patients increased considerably, leading to an
increasing age of opioid-dependent patients receiving OAT183-185. In Basel, Switzerland, the
proportion of patients with OAT aged 50 years and older increased tenfold between 1996 and 2003, while that of patients younger than 30 years plunged from 52% to 12%186. Due to their
history of drug abuse and its associated lifestyle, patients often appear prematurely aged and suffer from chronic diseases and disability, such as Arthritis, Hypertension, chronic lung disease, stomach ulcers, coronary disease, liver cirrhosis, or diabetes mellitus187. Additionally,
the prevalence of chronic infections, such as Hepatitis B and C or human immunodeficiency virus (HIV) are significantly higher compared to the general population183,184,188.
Consequently, many older patients with OAT often need additional long-term medications, resulting in polypharmacy and complex regimens. Together with a high prevalence of
psychological problems and low social support, these patients are at high risk for medication non-adherence.
Opioid-dependent patients often use other addictive substances, such as Alcohol, Nicotine, Cocaine, Amphetamines, or Benzodiazepines. In a representative sample of 578 persons with opioid use disorders, around 70% met criteria for dependence on an additional substance, and 20% were Cocaine-dependent189. Abuse of Cocaine is associated with negative health
effects and can trigger affective disorders and psychoses. Similar to OAT, there have been attempts to replace Cocaine with medications to avoid adverse effects. Although the stimulant Methylphenidate appears promising to be substituted for Cocaine, several randomized
Project C2 | Medication profiles of substituted patients with opioid dependence syndrome: A longitudinal observational study
90
controlled trials have not been able to show a reduction in Cocaine use or craving190. In
Switzerland, Methylphenidate is approved for the treatment of attention deficit hyperactivity disorder (ADHD) and for Narcolepsy. The global prevalence of adult ADHD has been
estimated at 3.4%191,192, but up to 30% of cocaine-dependent patients and 25% of patients
receiving OAT fulfil diagnostic criteria for adult ADHD. Especially in context with concomitant substance abuse, the prescription of Methylphenidate for adult ADHD should require a careful diagnosis and only long-acting formulations should be used193. Despites its potential
risk of abuse, the benefits of treatment with Methylphenidate for adult ADHD outweighs the potential risks194.
Rationale
The shift to an older age of patients with OAT poses multiple challenges for appropriate therapy. Apart from other risk factors, such as a high prevalence of psychological problems and low social support, increasing age and polypharmacy could be additional barriers to medication adherence for patients with opioid substitution therapy. Due to its interaction potential and possible side-effects, Methadone may not be ideal for OAT in older patients with polypharmacy. Other options are available, but there is a lack of information about the prevalence of their use. ADHD might be an additional risk factor associated with both substance use disorders and non-adherence195. Due to a high risk of abuse, the short-acting
Methylphenidate formulations do not offer benefits in the treatment of these patients and only the use of long-acting formulations is recommended. It is unclear how these
recommendations are being followed. One of the largest provider of OAT in Basel,
Switzerland, electronically registers all dispensed medicines in a database since 2002. The analysis of this data might offer a better understanding of the current medication profiles of this population with the potential to inform future work to improve medication supply and treatment in this setting.
Aims
Our goal was to establish a thorough understanding of the medication profiles of opioid dependent users in an outpatient addiction service (OAS) in Basel, Switzerland. We aimed to:
describe the demographics of the study population
assess the numbers and nature of medications dispensed to patients of the OAS with a focus on opioid substitution treatments, methylphenidate, and treatments for other comorbidities
Project C2 | Medication profiles of substituted patients with opioid dependence syndrome: A longitudinal observational study
91