Trends in carisoprodol abuse and misuse after regulatory scheduling: a retrospective review of California poison control calls from 2008 to 2015

Examination of multiple drug arrests reported to the Maine Diversion Alert Program

PURPOSE

Much of the responsibility for the increasing drug overdoses in the US has been attributed to opioids but most opioid overdoses also involve another drug. The objective of this study was to identify the drugs involved in polysubstance arrests. The substances that were more likely to be found in conjunction with other substances, using the drug arrests reported to Maine's Diversion Alert Program (DAP) were examined.

METHODS

Single and multiple drug arrests were quantified (N = 9,216). Multiple drug arrest percentages were compared to single drug arrest percentages to create a Multiple-to-Single Ratio (MSR) specific to each drug family and each drug to identify over (MSR > 1) and under-representation (MSR < 1).

RESULTS

Over three-fifths (63.8%) of all arrests involved a single drug. Opioids accounted for over-half (53.5%) of single arrests, followed by stimulants (27.7%) and hallucinogens (7.7%). Similarly, nearly two-fifths (39.6%) of multiple arrests were for opioids, followed by stimulants (30.8%) and miscellaneous (13.0%). Miscellaneous psychoactive prescription substances (e.g. clonidine, gabapentin, cyclobenzaprine, hydroxyzine) had the highest (1.51) MSR of any drug family. Conversely, stimulants (0.63), opioids (0.42), and hallucinogens (0.35) were significantly underrepresented in polysubstance arrests. Carisoprodol (8.80), amitriptyline (6.34), and quetiapine (4.69) had the highest MSR. Bath-salts (0.34), methamphetamine (0.44), and oxycodone (0.54) had the lowest MSR.

CONCLUSION

The misuse of opioids, both alone and in conjunction with another drug, deserves continued surveillance. In addition, common prescription drugs with less appreciated misuse potential, especially carisoprodol, amitriptyline, and quetiapine, require greater attention for their ability to enhance the effects of other drugs.

The impact of codeine upscheduling on overdoses, Emergency Department presentations and mortality in Victoria, Australia

BACKGROUND AND AIMS

Prior to February 2018, codeine was available over-the-counter (OTC) in Australia as a pharmacist-only medicine (Schedule 3) in low-strength formulations when in combination with simple analgesics. In February 2018, The Advisory Committee on Medicines Scheduling (ACMS) upscheduled codeine-containing medicines (CCM) to Schedule 4 (prescription-only medicine). This study aimed to determine the impact of upscheduling on prescriptions, overdoses and deaths.

METHODS

This study used interrupted time series analysis, a quasi-experimental design, to retrospectively evaluate the impact of upscheduling on overdose poisoning calls to the Victorian Poisons Information Centre (VPIC), Emergency Department (ED) presentations to Austin Health, and deaths reported to the Victorian Coroner from 1 January 2013-31 December 2019.

RESULTS

There was a significant reduction in the trend of high-strength codeine poisoning calls by 0.36 (P = 0.03, 95 % CI = [-0.69, -0.04]). Low-strength codeine poisoning calls to the VPIC reduced by 13.31 (P <0.001, 95 % CI = [-16.80, 9.82]]) calls in February 2018, followed by continued reduction of 0.12 calls per month. High-strength codeine overdose ED presentations reduced in the first quarter of 2018 by 3.72 presentations (P = 0.004, 95 % CI = [-6.13, -1.31]). Low-strength codeine overdose ED presentations after the first quarter of 2018 by 0.33 (P = 0.03, 95 % CI = [-0.63, -0.03]) presentations per month. Codeine-related deaths reduced by 7.19 (P < 0.001, 95 % CI = [-9.44, -4.94]) deaths in February 2018.

CONCLUSIONS

Codeine upscheduling to prescription-only medicine has reduced codeine-related poisoning calls, overdoses and unnatural death in Victoria.

Outcomes associated with scheduling or up-scheduling controlled substances

BACKGROUND

Many nations place drugs into various "schedules" according to their risk of abuse and/or recognized medical value that vary in terms of their restrictions. To mitigate diversion or abuse, drugs sometimes get rescheduled or are scheduled for the first time. Until now, there have not been efforts to integrate lessons from across the range of such past events.

METHODS AND DATA

We searched for peer-reviewed evaluations of instances of (re-)scheduling drugs in the United States after 1969 and a comparably large set of instances from other countries. Those 109 articles were supplemented by 30 others found in other ways but not meeting those search criteria (e.g., because the information on rescheduling was a minor part of a more general article).

FINDINGS

Findings are reported for many outcomes and with diverse measures over different timelines, making standardization of outcomes difficult. For more than half of the events for which quantitative outcomes were reported, there were declines in use-related measures by at least 40 percent. It is common for there to be reports of increases in indicators pertaining to other substances, sometimes more dangerous but sometimes less dangerous; overall, substitution appears to occur, but be partial.

CONCLUSION

Scheduling and up-scheduling can - though does not always - have substantial effects on a range of outcomes. Substitution to other substances is a possibility and so should be anticipated.

Codeine use and harms in Australia: evaluating the effects of re-scheduling

BACKGROUND AND AIMS

Globally, codeine is the most-used opioid. In December 2016, Australia announced that low-strength codeine (≤ 15 mg) would be re-scheduled and no longer available for purchase over-the-counter; this was implemented in February 2018. We aimed to evaluate the effect of this scheduling change on codeine misuse and use and misuse of other opioids.

DESIGN AND SETTING

Interrupted time-series analysis of monthly opioid exposure calls to New South Wales Poisons Information Centre (NSWPIC, captures 50% of Australia's poisoning calls), January 2015- January 2019 and monthly national codeine sales, March 2015-March 2019. We incorporated a washout period (January 2017 - January 2018) between the announcement and implementation, when prescriber/consumer behaviour may have been influenced.

PARTICIPANTS

Intentional opioid overdoses resulting in a call to NSWPIC.

MEASUREMENTS

We used linear segmented regression to identify abrupt changes in level and slope of fitted lines. Codeine poisonings and sales were stratified into high strength (> 15 mg per dose unit) and low strength (≤ 15 mg). Only low-strength formulations were re-scheduled.

FINDINGS

We observed an abrupt -50.8 percentage [95% confidence interval (CI) = -79.0 to -22.6%] level change in monthly codeine-related poisonings and no change in slope in the 12 months after February 2018. There was no increase in calls to the NSWPIC for high-strength products, level change: -37.2% (95% CI = -82.3 to 8%) or non-codeine opioids, level change: -4.4% (95% CI = -33.3 to 24.4%). Overall, the re-scheduling resulted in a level change in opioid calls of -35.8% calls/month (95% CI = -51.2 to -20.4%). Low-strength codeine sales decreased by 87.3% (95% CI = -88.5 to -85.9%), with no increase in high-strength codeine sales in the 14 months following re-scheduling, -4.0% (95% CI = -19.6 to 14.6%).

CONCLUSIONS

Codeine re-scheduling in Australia appears to have reduced codeine misuse and sales.

Impact of Schedule IV controlled substance classification on carisoprodol utilization in the United States: An interrupted time series analysis

BACKGROUND

In January 2012, the Drug Enforcement Agency (DEA) classified carisoprodol as a Schedule IV controlled substance at the US federal level. We aimed to examine the effect of this policy on the use of carisoprodol in a commercially-insured population.

METHODS

This interrupted time series study included individuals with musculoskeletal disorders in the IBM MarketScan Commercial Database between December 2009 and February 2014. We used comparative segmented linear regression to assess changes in the proportions of patients who filled/newly filled carisoprodol each month.

RESULTS

A total of 13.3 million patients were included. 29 states with no scheduling prior to the DEA classification had lower baseline prevalence of carisoprodol use compared to 17 states that had scheduled carisoprodol individually before 2010 (11.0 vs. 21.1 patients with fills per 1000 patients). The federal scheduling was associated with an immediate decline (-1.12 per 1000 patients, p < 0.01) and decreasing trend in prevalence (-0.07 per 1000 patients per month, p = 0.02). This effect was not modified by existing state-level scheduling status. During the first, second, third, and fourth 6-month periods after federal scheduling, the relative difference between observed and predicted prevalence was 7.8%, 10.5%, 13.4%, and 19.8%. Similar patterns were observed for carisoprodol initiation. Overall, declining use was more pronounced among younger age groups and patients with injury.

CONCLUSIONS

Schedule IV controlled substance classification at the federal level was associated with a moderate reduction in the dispensing of carisoprodol regardless of whether scheduling was already present at the state level.