Editing Oxycodone (section)

====Duration of action====
Oral oxycodone has a half-life of 4.5 hours.<ref name="Drugbank"/> It is available as a [[generic medication]].<ref name="AHFS2018" /> The manufacturer of OxyContin, a controlled-release preparation of oxycodone, [[Purdue Pharma]], claimed in their 1992 patent application that the duration of action of OxyContin is 12 hours in "90% of patients". It has never performed any clinical studies in which OxyContin was given at more frequent intervals. In a separate filing, Purdue claims that controlled-release oxycodone "provides pain relief in said patient for at least 12 hours after administration".<ref name="latimes2016">{{cite news |vauthors=Ryan H, Girion L, Glover S |title=You want a description of hell?' OxyContin's 12-hour problem |url=https://www.latimes.com/projects/oxycontin-part1/ |access-date=8 July 2018 |work=Los Angeles Times |date=7 July 2016 |archive-date=1 July 2018 |archive-url=https://web.archive.org/web/20180701135355/http://www.latimes.com/projects/oxycontin-part1/ |url-status=live }}</ref> However, in 2016 an investigation by the ''[[Los Angeles Times]]'' found that "the drug wears off hours early in many people", inducing symptoms of [[opiate withdrawal]] and intense cravings for OxyContin. One doctor, Lawrence Robbins, told journalists that over 70% of his patients would report that OxyContin would only provide 4–7 hours of relief. Doctors in the 1990s often would switch their patients to a dosing schedule of once every eight hours when they complained that the duration of action for OxyContin was too short to be taken only twice a day.<ref name="latimes2016"/><ref name="oxycontinfiles">{{cite news |title='Q12' Workshops, 2001 |url=http://documents.latimes.com/q12-workshops-2001/ |newspaper=Los Angeles Times |access-date=8 July 2018 |archive-date=21 April 2018 |archive-url=https://web.archive.org/web/20180421121121/http://documents.latimes.com/q12-workshops-2001/ |url-status=live }}</ref> Mean serum concentration of controlled-release oxycodone peaks at 78 ng/ml at 1 hour and drops to 20 ng/ml at 8 hours and under 10 ng/ml at 12 hours.<ref name="DDD13.8" />

Purdue strongly discouraged the practice: Purdue's medical director Robert Reder wrote to one doctor in 1995 that " OxyContin has been developed for [12-hour] dosing...I request that you not use a [8-hourly] dosing regimen." Purdue repeatedly released memos to its sales representatives ordering them to remind doctors not to deviate from a 12-hour dosing schedule. One such memo read, "There is no Q8 dosing with OxyContin... [8-hour dosing] needs to be nipped in the bud. NOW!!"<ref name="latimes2016"/> The journalists who covered the investigation argued that Purdue Pharma has insisted on a 12-hour duration of action for nearly all patients, despite evidence to the contrary, to protect the reputation of OxyContin as a 12-hour drug and the willingness of [[health insurance]] and [[managed care]] companies to cover OxyContin despite its high cost relative to generic opiates such as morphine.<ref name="latimes2016"/>

Purdue sales representatives were instructed to encourage doctors to write prescriptions for larger 12-hour doses instead of more frequent dosing. An August 1996 memo to Purdue sales representatives in Tennessee entitled "$$$$$$$$$$$$$ It's Bonus Time in the Neighborhood!" reminded the representatives that their commissions would dramatically increase if they were successful in convincing doctors to prescribe larger doses. ''Los Angeles Times'' journalists argue using interviews from opioid addiction experts that such high doses of OxyContin spaced 12 hours apart create a combination of agony during opiate withdrawal (lower lows) and a [[schedule of reinforcement]] that relieves this agony fostering addiction.<ref name="latimes2016"/>

As of 2024, the [[Medication package insert|prescribing information]] for OxyContin still specifies a controversial 12-hour dosing schedule - which experts say promotes addiction - as the only option;<ref name="Oxycontin FDA label" /><ref>{{Cite web |title=OxyContin Investigation |url=https://www.latimes.com/projects/la-me-oxycontin-full-coverage/ |access-date=2025-03-08 |website=www.latimes.com |language=en}}</ref> it also still states, "there are no well-controlled clinical studies evaluating the safety and efficacy with dosing more frequently than every 12 hours."<ref name="Oxycontin FDA label" />