Feasibility and acceptability of an intranasal diamorphine spray as an alternative to injectable diamorphine for maintenance treatment

Heroin and its metabolites: relevance to heroin use disorder

Heroin is an opioid agonist commonly abused for its rewarding effects. Since its synthesis at the end of the nineteenth century, its popularity as a recreational drug has ebbed and flowed. In the last three decades, heroin use has increased again, and yet the pharmacology of heroin is still poorly understood. After entering the body, heroin is rapidly deacetylated to 6-monoacetylmorphine (6-MAM), which is then deacetylated to morphine. Thus, drug addiction literature has long settled on the notion that heroin is little more than a pro-drug. In contrast to these former views, we will argue for a more complex interplay among heroin and its active metabolites: 6-MAM, morphine, and morphine-6-glucuronide (M6G). In particular, we propose that the complex temporal pattern of heroin effects results from the sequential, only partially overlapping, actions not only of 6-MAM, morphine, and M6G, but also of heroin per se, which, therefore, should not be seen as a mere brain-delivery system for its active metabolites. We will first review the literature concerning the pharmacokinetics and pharmacodynamics of heroin and its metabolites, then examine their neural and behavioral effects, and finally discuss the possible implications of these data for a better understanding of opioid reward and heroin addiction. By so doing we hope to highlight research topics to be investigated by future clinical and pre-clinical studies.

Feasibility, safety, and acceptability of intranasal heroin-assisted treatment in Switzerland: protocol for a prospective multicentre observational cohort study

BACKGROUND

Heroin-assisted treatment (HAT) is a proven effective treatment option for individuals with severe opioid use disorder (OUD). In Switzerland, pharmaceutical heroin (diacetylmorphine, DAM) is available in tablet form or as injectable liquid. This creates a large barrier for individuals who require the rapid onset of effect but are either unable or do not want to inject, or who primarily snort opioids. Early experimental data has demonstrated that intranasal DAM administration can be a viable alternative to the intravenous or intramuscular route of administration. The purpose of this study is to assess the feasibility, safety, and acceptability of intranasal HAT.

METHODS

This study will assess intranasal DAM using a prospective multicentre observational cohort study design in HAT clinics across Switzerland. Patients will be offered to switch from oral or injectable DAM to intranasal DAM. Participants will be followed-up over 3 years, with assessments at baseline, and after 4, 52, 104 and 156 weeks. The primary outcome measure (POM) is retention in treatment. Secondary outcomes (SOM) include prescriptions and routes of administration of other opioid agonists, illicit substance use, risk behaviour, delinquency, health and social functioning, treatment adherence, opioid craving, satisfaction, subjective effects, quality of life, physical health, and mental health.

CONCLUSIONS

The results derived from this study will generate the first major body of clinical evidence on the safety, acceptability, and feasibility of intranasal HAT. If proven to be safe, feasible and acceptable, this study would increase the accessibility of intranasal OAT for individuals with OUD globally as a critical improvement in risk reduction.

Safety and feasibility of intranasal heroin-assisted treatment: 4-week preliminary findings from a Swiss multicentre observational study

BACKGROUND

Heroin-assisted treatment (HAT) is effective for individuals with severe opioid use disorder (OUD) who do not respond sufficiently to other opioid agonist treatments. It is mostly offered with injectable diacetylmorphine (DAM) or DAM tablets creating a barrier for individuals who need the rapid onset of action but are either unable or unwilling to inject, or primarily snort opioids. To explore another route of administration, we evaluated the safety and feasibility of intranasal (IN) DAM.

METHODS

This is a multicentre observational cohort study among patients in Swiss HAT. All patients planning to receive IN DAM within the treatment centres were eligible to participate. Participants were either completely switched to IN DAM or received IN DAM in addition to other DAM formulations or opioid agonists. Patients were followed up for four weeks. Sociodemographic characteristics, current HAT regimen, reasons for starting IN DAM, IN DAM doses, number of injection events in the sample, IN DAM continuation rate, and appearance of adverse events and nose-related problems were evaluated.

RESULTS

Participants (n = 52) reported vein damage, preference for nasal route of administration, and desire of a stronger effect or for a less harmful route of administration as primary reasons for switching to IN DAM. After four weeks, 90.4% of participants (n = 47) still received IN DAM. Weekly average realised injection events decreased by 44.4% from the month before IN DAM initiation to the month following. No severe adverse events were reported.

CONCLUSIONS

After four weeks, IN DAM was a feasible and safe alternative to other routes of administration for patients with severe OUD in HAT. It addressed the needs of individuals with OUD and reduced injection behaviour. More long-term research efforts are needed to systematically assess efficacy of and patient satisfaction with IN DAM.

Nasal Opioid Agonist Treatment in Patients with Severe Opioid Dependence: A Case Series

INTRODUCTION

Opioid agonist treatment (OAT) is the first-line treatment for opioid dependence. Currently available OAT options comprise oral (methadone and morphine) and sublingual (buprenorphine) routes of administration. In Switzerland and some other countries, severely opioid-dependent individuals with insufficient response to oral or sublingual OAT are offered heroin-assisted treatment (HAT), which involves the provision of injected or oral medical heroin (diacetylmorphine [DAM]). However, many patients on treatment with injectable DAM (i-HAT) suffer from injection-related problems such as deteriorated vein status, ulcerations, endocarditis, and abscesses. Other patients who do not respond to oral OAT do not inject but snort opioids, and are not eligible for i-HAT. For this population, there is no other short-acting OAT with rapid onset of action available unless they switch to injecting, which is associated with higher risks. Nasal DAM (n-HAT) could be an alternative treatment option suitable for both populations of patients.

METHODS

We present a case series of 3 patients on i-HAT who successfully switched to n-HAT.

RESULTS/CONCLUSIONS

This is the first description of the clinical use of the nasal route of administration for HAT. n-HAT may constitute an important risk-reduced rapid-onset alternative to i-HAT. In particular, it may be suited for patients with injection-related complications, or noninjecting opioid-dependent patients failing to respond to oral OAT.

Prescription of heroin for the management of heroin dependence: current status

The prescription of heroin (diamorphine) for the management of heroin dependence is a controversial treatment approach that was limited to Britain until the 1990s. Since then a number of countries have embarked upon clinical trials of this approach, and it is currently licensed and available in several European countries. To date, six randomized controlled trials (RCTs) with over 1600 patients and several cohort studies have examined injected (or inhaled) heroin treatment. This article reviews relevant clinical pharmacology, how heroin treatment programmes are delivered, and the evidence regarding safety, efficacy and cost-effectiveness from RCTs. Heroin is usually prescribed in intravenous dosages of 300-500 mg/day, divided in two or three doses. Uncommon but serious side effects include seizures and respiratory depression immediately following injection. Despite methodological shortcomings, RCTs generally indicate that heroin treatment results in a comparable retention, improved general health and psychosocial functioning, and less self-reported illicit heroin use than oral methadone treatment. Cost-effectiveness studies indicate heroin treatment to be more expensive to deliver but to result in savings in the criminal justice sector. There has been debate regarding how heroin treatment should be positioned within the range of treatment approaches for this condition. There is increasing consensus that, in countries that have robust and accessible treatment systems for heroin users, heroin treatment is suited to a minority of heroin users as a second-line treatment for those individuals who do not respond to methadone or buprenorphine treatment delivered under optimal conditions.

Recent advances in the pharmacological management of pain

Pain is an unpleasant sensation that originates from ongoing or impending tissue damage. Management of different types of pain (acute, postoperative, inflammatory, neuropathic or cancer) is the most frequent issue encountered by clinicians and pharmacological therapy is the first line of approach for the treatment of pain. This review presents and discusses recent clinical advances regarding both the improvements in delivery of analgesic drugs and improvements in the design of analgesic molecules. The new modalities of administration of analgesics used in the clinic are reviewed, including skin patches, oral and mucosal sprays, transdermal delivery systems and intranasal administration. New insights are then presented on standard drugs used to relieve pain, such as opioids (including tramadol), NSAIDs including selective cyclo-oxygenase-2 inhibitors, paracetamol (acetaminophen), local anaesthetics and adjuvant analgesics such as antidepressants, anticonvulsants (gabapentin and pregabalin), cannabinoids, ketamine and others (e.g. nefopam). Although the understanding of pain mechanisms has improved significantly recently, much more is yet to be discovered and awaited. Broadening of our knowledge is needed to improve basic and clinical research in this field in order to better alleviate pain in millions of people.

Endogenous opiates and behavior: 2006

This paper is the 29th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning 30 years of research. It summarizes papers published during 2006 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurological disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).

Opioid maintenance: a comparative review of pharmacological strategies

The use of opioids outside of medical practice is a significant health problem with important social and political implications. Although treatment of opioid dependence is traditionally focused on heroin users, there is increasing recognition that a large number of people become dependent through the use of prescription opioids. The necessity for long-term treatment has also been increasingly recognised. At present, there are several pharmacotherapies available for maintenance treatment, including drugs that are full agonists at the opioid receptor (e.g., methadone, slow-release oral morphine), a partial agonist (buprenorphine) and an opioid antagonist (naltrexone). This review examines the existing strategies, highlights problems associated with their use and discusses the opportunities for new treatment approaches, particularly the use of long-acting formulations.