BackgroundThe Pharmaceutical Benefits Scheme (PBS) is Australia’s national drug subsidy program. This paper provides a practical guide to researchers using PBS data to examine prescribed medicine use.FindingsExcerpts of the PBS data collection are available in a variety of formats. We describe the core components of four publicly available extracts (the Australian Statistics on Medicines, PBS statistics online, section 85 extract, under co-payment extract). We also detail common analytical challenges and key issues regarding the interpretation of utilisation using the PBS collection and its various extracts.ConclusionsResearch using routinely collected data is increasing internationally. PBS data are a valuable resource for Australian pharmacoepidemiological and pharmaceutical policy research. A detailed knowledge of the PBS, the nuances of data capture, and the extracts available for research purposes are necessary to ensure robust methodology, interpretation, and translation of study findings into policy and practice.

Psychotropic utilisation markedly increased in Australia between 2000 and 2011. Some potential concerns include: (1) the continuing high use of benzodiazepines, particularly alprazolam, despite their problematic effects; (2) the rapid increase in serotonin noradrenaline reuptake inhibitor (SNRI) use, given their more complex side-effect profile relative to selective serotonin reuptake inhibitors (SSRIs); and (3) the dramatic increase in antidepressant prescriptions despite questions about the efficacy of these drugs in mild to moderate depression. Finally, some limitations are identified regarding use of the DDDs/1000/day metric, which can distort estimates of utilisation of specific drugs when the defined daily dose is higher or lower than the formulation most commonly dispensed by pharmacies.

Aim The aim of this paper is to investigate 25‐year trends in community use of prescribed opioid analgesics in Australia, and to map these trends against major changes to opioid registration and subsidy. Methods We obtained dispensing data from 1990 to 2014 from two sources: dispensing claims processed under Australia's national drug subsidy programme, the Pharmaceutical Benefits Scheme, including under co‐payment records from 2012; and estimates of non‐subsidized medicine use from a survey of Australian pharmacies (until 2011). Utilization was expressed in defined daily doses (DDD)/1000 population/day. Results Opioid dispensing increased almost four‐fold between 1990 and 2014, from 4.6 to 17.4 DDD/1000 pop/day. In 1990, weak, short‐acting or orally administered opioids accounted for over 90% of utilization. Use of long‐acting opioids increased over 17‐fold between 1990 and 2000, due primarily to the subsidy of long‐acting morphine and increased use of methadone for pain management. Between 2000 and 2011, oxycodone, fentanyl, buprenorphine, tramadol and hydromorphone use increased markedly. Use of strong opioids, long‐acting and transdermal preparations also increased, largely following the subsidy of various opioids for noncancer pain. In 2011, the most dispensed opioids were codeine (41.1% of total opioid use), oxycodone (19.7%) and tramadol (16.1%); long‐acting formulations comprised approximately half, and strong opioids 40%, of opioid dispensing. Conclusions Opioid utilization in Australia is increasing, although these figures remain below levels reported in the US and Canada. The increased use of opioids was largely driven by the subsidy of long‐acting formulations and opioids for the treatment of noncancer pain.

ObjectivesTo examine the knowledge and attitudes of Australian general practitioners (GP) towards medicinal cannabis, including patient demand, GP perceptions of therapeutic effects and potential harms, perceived knowledge and willingness to prescribe.Design, setting and participantsA cross-sectional survey completed by 640 GPs (response rate=37%) attending multiple-topic educational seminars in five major Australian cities between August and November 2017.Main outcome measuresNumber of patients enquiring about medicinal cannabis, perceived knowledge of GPs, conditions where GPs perceived it to be beneficial, willingness to prescribe, preferred models of access, perceived adverse effects and safety relative to other prescription drugs.ResultsThe majority of GPs (61.5%) reported one or more patient enquiries about medicinal cannabis in the last three months. Most felt that their own knowledge was inadequate and only 28.8% felt comfortable discussing medicinal cannabis with patients. Over half (56.5%) supported availability on prescription, with the preferred access model involving trained GPs prescribing independently of specialists. Support for use of medicinal cannabis was condition-specific, with strong support for use in cancer pain, palliative care and epilepsy, and much lower support for use in depression and anxiety.ConclusionsThe majority of GPs are supportive or neutral with regards to medicinal cannabis use. Our results highlight the need for improved training of GPs around medicinal cannabis, and the discrepancy between GP-preferred models of access and the current specialist-led models.

CBD can potentiate the psychoactive and physiological effects of THC in rats, most likely by delaying the metabolism and elimination of THC through an action on the CYP450 enzymes that metabolise both drugs.

Dispensing of psychotropic medications increased markedly from 2009 to 2012, with notable age-specific trends. General adherence to treatment guidelines is apparent, yet concerns exist regarding rapid increases in serotonin noradrenaline reuptake inhibitor (SNRI) antidepressant prescribing, the likely overmedication of persons with mild psychological distress, and the increasing use of powerful psychotropic medications in younger populations despite uncertain risk-benefit profiles.

Mephedrone (4-methylmethcathinone, MMC) is a popular recreational drug, yet its potential harms are yet to be fully established. The current study examined the impact of single or repeated MMC exposure on various neurochemical and behavioral measures in rats. In Experiment 1 male adolescent Wistar rats received single or repeated (once a day for 10 days) injections of MMC (30 mg/kg) or the comparator drug methamphetamine (METH, 2.5 mg/kg). Both MMC and METH caused robust hyperactivity in the 1 h following injection although this effect did not tend to sensitize with repeated treatment. Striatal dopamine (DA) levels were increased 1 h following either METH or MMC while striatal and hippocampal serotonin (5-HT) levels were decreased 1 h following MMC but not METH. MMC caused greater increases in 5-HT metabolism and greater reductions in DA metabolism in rats that had been previously exposed to MMC. Autoradiographic analysis showed no signs of neuroinflammation ([125I]CLINDE ligand used as a marker for translocator protein (TSPO) expression) with repeated exposure to either MMC or METH. In Experiment 2, rats received repeated MMC (7.5, 15 or 30 mg/kg once a day for 10 days) and were examined for residual behavioral effects following treatment. Repeated high (30 mg/kg) dose MMC produced impaired novel object recognition 5 weeks after drug treatment. However, no residual changes in 5-HT or DA tissue levels were observed at 7 weeks post-treatment. Overall these results show that MMC causes acute but not lasting changes in DA and 5-HT tissue concentrations. MMC can also cause long-term memory impairment. Future studies of cognitive function in MMC users are clearly warranted.

ObjectivesTo characterise trends in self-poisoning and psychotropic medicine use in young Australians.DesignPopulation-based retrospective cohort study.SettingCalls taken by the New South Wales and Victorian Poisons Information Centres (2006–2016, accounting for 70% of Australian poisoning calls); medicine dispensings in the 10% sample of Australian Pharmaceutical Benefits Scheme data (July 2012 to June 2016).ParticipantsPeople aged 5–19 years.Main outcome measuresYearly trends in intentional poisoning exposure calls, substances taken in intentional poisonings, a prevalence of psychotropic use (dispensing of antidepressants, antipsychotics, benzodiazepines and medicines for attention deficit hyperactivity disorder (ADHD)).ResultsThere were 33 501 intentional poisonings in people aged 5–19 years, with an increase of 8.39% per year (95% CI 6.08% to 10.74%, p<0.0001), with a 98% increase overall, 2006–2016. This effect was driven by increased poisonings in those born after 1997, suggesting a birth cohort effect. Females outnumbered males 3:1. Substances most commonly taken in self-poisonings were paracetamol, ibuprofen, fluoxetine, ethanol, quetiapine, paracetamol/opioid combinations, sertraline and escitalopram. Psychotropic dispensing also increased, with selective serotonin reuptake inhibitors (SSRIs) increasing 40% and 35% July 2012 to June 2016 in those aged 5–14 and 15–19, respectively. Fluoxetine was the most dispensed SSRI. Antipsychotics increased by 13% and 10%, while ADHD medication dispensing increased by 16% and 10%, in those aged 5–14 and 15–19, respectively. Conversely, dispensing of benzodiazepines to these age groups decreased by 4% and 5%, respectively.ConclusionsOur results signal a generation that is increasingly engaging in self-harm and is increasingly prescribed psychotropic medications. These findings indicate growing mental distress in this cohort. Since people who self-harm are at increased risk of suicide later in life, these results may foretell future increases in suicide rates in Australia.