Prevalence and associations of quetiapine fumarate misuse among an Australian national city sample of people who regularly inject drugs

Abstract

Aims To estimate the prevalence of self-reported misuse of the antipsychotic quetiapine fumarate (quetiapine) among a sample of urban Australian people who inject drugs (PWID), and correlates of reported misuse in health and social domains. Design, setting and participants Data were obtained from a national cross-sectional convenience sample survey of 868 urban PWID. Measurements Self-reported life-time and recent (past 6-month) use, and mode of use, of prescribed and non-prescribed quetiapine. 'Misuse' calculated on non-oral use of the prescribed drug or non-prescribed use. Self-reported potential correlates of quetiapine misuse including socio-demographic, drug use and health and social characteristics. Findings Thirty-one per cent of the sample [95% confidence interval (CI) = 28-34%] reported ever misusing quetiapine, 15% (95% CI = 13-17%) in the preceding 6 months. Multivariate logistic analysis showed that participants reporting any recent quetiapine misuse were more likely to be from jurisdictions with higher population prescription rates. They were also more likely to report violent crime in the preceding month [odds ratio (OR) = 1.96, 95% CI = 1.17-3.29] and non-heroin drug overdose in the preceding 12 months (OR = 3.52, 95% CI = 1.39-8.91). Recent quetiapine misuse was also significantly associated with non-prescribed benzodiazepine use (OR = 4.26, 95% CI = 2.06-8.82), non-prescribed pharmaceutical opioid use (OR = 2.76 95% CI 1. 47-5.19) and amphetamine use (OR = 2.08, 95% CI = 1.02-4.22) in the previous 6 months. Conclusions Quetiapine misuse appears to be common in PWID in urban Australia. Recent misuse is associated with localities reporting a higher rate of prescriptions and among individuals with a history of non-heroin drug overdose, violent crime and use of nonprescribed benzodiazepines and pharmaceutical opioids as well as amphetamines. Awareness of the potential for quetiapine misuse is important, as the drug is prescribed increasingly in a broader range of approved and 'off-label' clinical contexts.

Quetiapine and olanzapine misuse prevalence in a US general population sample

“…This pattern is in line with previous studies that have also identified SGA misuse commonly occurring in conjunction with other substances, such as opioids, anxiolytics, sedatives, antidepressants, or stimulants. 8 , 10 , 23 , 28 , 30 Despite the tendency to misuse in conjunction with other CNS depressants, in the present study, most participants reported misuse no more frequently than monthly; this infrequent misuse pattern of quetiapine specifically has been previously reported among a sample of persons who regularly inject drugs. 30 …”

“…Other studies have assessed healthcare use 6 , 8 , 10 or postmortem toxicology data; 6 , 22 these select mainly patients experiencing harm associated with their misuse. Finally, studies have also estimated misuse within specific subpopulations, such as individuals with known use disorders, 3 , 4 , 23 individuals receiving psychiatric care in the hospital, 24 or incarcerated populations. 25 While such individuals are more likely to engage in SGA use, their sampling doesn't enhance understanding of the generalized scope of misuse.…”

Quetiapine Abuse in Illicit Drug Users or Sellers: To Screen or Not to Screen?

“…In 2014, Reddel et al (22) In a recent prevalence study based on quetiapine abuse among users of illicit substances, 15% of quetiapine users have been identified. In addition, quetiapine-related deaths have generally occurred in cases of multiple drug use (23,24).…”

Extra‐medical use of antipsychotics: what can be learnt from experiences with other prescription medicines?

“…Reports of increased extra‐medical use (i.e. use outside the bounds of a doctor's prescription) of SGAs—most commonly quetiapine, followed by olanzapine —have surfaced, with evidence of potential harms such as non‐fatal and fatal overdose . Increased availability of SGAs from off‐label prescribing may have contributed to their extra‐medical use.…”

“…Most reports of extra‐medical use of SGAs come from populations typically at higher risk of such use (e.g. people who are incarcerated, in alcohol and drug treatment services or use illicit drugs) . These studies indicate that motives for use mainly relate to: self‐medication of anxiety, sleep disturbance, insomnia and depression; attenuation of negative effects of consuming or withdrawing from other substances; and enhancement of pleasurable effects through the co‐ingestion of other substances .…”