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Clin Toxicol (Phila). 2016 Jun;54(5):434-40. doi: 10.3109/15563650.2016.1148720. Epub 2016 Feb 26.

Trends in analgesic exposures reported to Texas Poison Centers following increased regulation of hydrocodone.

Author information

a Emergency Medicine/Division of Toxicology , University of Texas Southwestern , Dallas , TX , USA ;
b Texas Department of State Health Services , Austin , TX , USA.



In October 2014, the Drug Enforcement Administration reclassified hydrocodone to schedule II, increasing regulations on use. The impact of rescheduling hydrocodone on opioid exposures is unclear, especially in states with special restrictions required for prescribing schedule II agents.


To assess whether changes in exposures to prescription opioid analgesics and heroin as reported to poison centers occurred in the 6 months after hydrocodone rescheduling. We hypothesized that hydrocodone exposures would decrease, while less tightly regulated opioids, such as codeine and tramadol, would increase.


This study compares opioid analgesic exposures reported to Texas Poison Centers before and after this change in a state that requires special prescription pads for Schedule II agents. Cases included all opioid analgesic exposures reported to a statewide poison center network, comparing exposures from 6 months before to 6 months after heightened regulations. Specific opioids with large changes in reported exposures were further characterized by patient age and exposure intent.


Hydrocodone exposures decreased from 1567 to 1135 (28%, p = 0.00017), decreasing for all ages. Codeine exposures increased significantly from 189 to 522 (176%, p = 0.00014), including a 263% increase for age >20 years. Codeine misuse increased 443% and adverse drug events 327%. Oxycodone exposures increased from 134 to 189 (39%, p = 0.0143), increasing only among patients age >20 years. Reported heroin exposures increased from 156 to 179 (15%, p = 0.2286) and tramadol from 666 to 708 (6%, p = 0.0193). Other opioid exposures changed little or had limited reports.


The increased regulation of hydrocodone was followed temporally by a decrease in reported hydrocodone exposures, but also increases in codeine, oxycodone and tramadol exposures. This may reflect a shift in prescribing practices, changes in street availability of hydrocodone or decreased drug diversion.


The increased regulation was temporally associated with decreased hydrocodone exposures reported to Texas Poison Centers.


Analgesics; codeine; drug and narcotic control; drug exposure patterns/trends; hydrocodone; opioid

[Indexed for MEDLINE]

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