Abuse potential of carbamazepine

Rising pregabalin use and misuse in Australia: trends in utilization and intentional poisonings

BACKGROUND AND AIMS

Pregabalin is a gamma-aminobutyric acid (GABA) analogue, used to treat neuropathic pain and epilepsy. Pregabalin was registered in Australia in 2005, and subsidized publically in 2013. We aimed to describe Australian patterns of pregabalin use and intentional poisoning, and identify people potentially at high risk of misuse.

DESIGN AND SETTING

Population-based retrospective cohort study of dispensings in the 10% sample of Australian Pharmaceutical Benefits Scheme (July 2012-February 2017); intentional poisoning calls to New South Wales Poisons Information Centre (NSWPIC) (2004-2016); intentional poisonings in two Australian toxicology service databases; and poisoning fatalities in NSW coronial records (2005-2016).

PARTICIPANTS

A total of 122 572 people dispensed pregabalin, people with intentional pregabalin overdoses managed by NSWPIC and the toxicology services and pregabalin-associated deaths referred to the NSW coroner.

MEASUREMENTS

Trends in dispensing, poisoning, death; demographics and patient characteristics, proportion of users at high risk of misuse (latent class analysis, LCA) and characteristics of high-risk users.

FINDINGS

Pregabalin dispensing increased by 73 424 per year [95% confidence interval (CI) = 61726-85 121 P < 0.001] between 2013 and 2016. NSWPIC received 1158 reports of intentional pregabalin poisonings, with a 53.8% increase per year, 2005-2016 (95% CI = 44.0-64.2%, P < 0.001). We identified 88 pregabalin-associated deaths, 57.8% yearly increase (95% CI = 30.0-91.6%, P < 0.001). Patients overdosing on pregabalin commonly co-ingested opioids, benzodiazepines and illicit drugs, and had high rates of psychiatric and substance use comorbidities; 14.7% of pregabalin users were classed by the LCA as at high risk of misuse, and were more likely to be younger, male, co-prescribed benzodiazepines or opioids, have more individual prescribers and higher pregabalin strengths dispensed.

CONCLUSIONS

There has been a dramatic increase in pregabalin use, poisonings and deaths in Australia since it became subsidized publicly in 2013. One in seven Australians dispensed pregabalin appears to be at high risk of misuse.

Psychoactive Medication Misadventuring in Correctional Health Care

Due to multiple factors, unprecedented numbers of individuals with mental health disorders and many with comorbid substance use disorders are now incarcerated in jails and prisons. This article details a variety of medication use and potential abuse/misuse/misadventuring topics that are unique to the correctional health care setting, with emphasis on how the large number of persons with psychiatric and/or substance use disorders affects these issues and methods that correctional systems commonly use to manage these inmate-patients. Also discussed are the potential for inmate feigning or malingering as a goal-directed behavior, potential for misadventuring/abuse of commonly used medications, urine drug screening/surveillance, and the effect of psychoactive medications on heat tolerance and environmental issues.

Effects of carbamazepine on morphine-induced behavioral sensitization in mice

Effects of carbamazepine on behavioral sensitization to morphine in mice has been investigated. Mice treated daily for 7 days with morphine (10 mg/kg) induced behavioral sensitization. Carbamazepine (10, 20, 40 mg/kg, i.p.) itself dose-dependently inhibited the locomotor activity of mice, but did not affect the acute morphine induced hyperactivity. Chronic treatment with carbamazepine had no effect on the development of morphine behavioral sensitization. Co-administration of carbamazepine 30 min prior to morphine had no significant effect on the development of behavioral sensitization. After the behavioral sensitization has been established, carbamazepine (10, 20, 40mg/kg, i.p.) did not affect the expression of morphine sensitization. However, carbamazepine (10, 20, 40mg/kg, i.p.) dose-dependently potentiated the transfer of morphine sensitization. The data of the present study implies that carbamazepine may influence the maintenance process of behavioral sensitization, which results in the enhancement of the transfer of behavioral sensitization. In clinic, the present results suggest that chronic use of carbamazepine might have abuse potential in opioid abusers.

Recreational overdosage of carbamazepine in Paisley drug abusers

Oral drug abuse is a major social and medical issue. Paisley, in the West of Scotland, has become infamous for its problem with oral temazepam abuse. With the crack down on the prescription of temazepam in our area and the resultant lack of its supply on the streets, drug abusers appear to be experimenting with new drugs for their psychotropic effects. We report five cases of recreational carbamazepine overdosage in young temazepam abusers.

Is carbamazepine a potential drug of abuse?

A case is reported of a 20-year-old female student who had been abusing carbamazepine with alcohol and described a resulting sense of euphoria. The literature is reviewed for evidence to support this claim, and possible mechanisms to account for the euphorigenic effect of alcohol and carbamazepine are discussed.

Prolonged treatment with carbamazepine increases the stimulatory effects of ethanol in mice

Carbamazepine (CBZ) has been used in the treatment of alcohol withdrawal (AW). However, cases of induction of euphoric feelings when mixed with alcohol have been reported. We verified whether CBZ could potentiate ethanol stimulatory effects in animals. Two groups of mice were injected with saline (group I) or 2 g/kg ethanol (group II) IP, for 20 days. On the next day, each group was divided into two subgroups that received either a single dose of CBZ (10 mg/kg) or vehicle IP, followed, 30 min later, by saline or ethanol injection. Locomotor activity was measured. Acute CBZ did not change locomotor activity of ethanol-treated mice. Treatment with CBZ or vehicle continued for 6 days. Finally, on the 28th day, 30 min after the last CBZ or vehicle injection, an ethanol challenge was given to group II and a saline injection to group I. The results showed a significant potentiation of ethanol stimulatory effects by chronic CBZ treatment. Data indicated that CBZ should be cautiously administered to alcohol-dependent patients.