Abuse Potential of IRO-A and IRO Tablets

Las Vegas—A single-center, randomized, double-blind study found that an immediate-release oxycodone hydrochloride formulation (IRO-A) had a lesser potential for abuse compared with commercially available immediate-release oxycodone hydrochloride (IRO) when crushed and administered intranasally in nondependent, recreational opioid users.

The results were presented at the AAPM meeting during a poster presentation titled Intranasal Abuse Potential of an IR Oxycodone Formulation. Although 91% of opioid prescriptions are immediate-release formulations, immediate-release formulations are responsible for more instances of misuse, abuse, and diversion compared with extended-release formulations, according to the authors. IRO-A is intended to reduce intranasal and intravenous abuse for patients with moderate-to-severe pain. Eligibility criteria included healthy patients between 18 and 55 years of age who had used opioids for nontherapeutic purposes ≥10 times in the previous year and ≥1 time in the 12 weeks before screening as well as opioids intranasally ≥3 times in the previous year. Of the 40 patients who received ≥1 dose of the study drug, the mean age was 35.7 years, while 80% of patients were males and 75% were white.

Each patient insufflated IRO, but 21 of 40 patients could not insufflate IRO-A because of blocked nasal passages, the drug falling from the nose after snorting, or vomiting. One patient was excluded from the evaluation phase after vomiting. During the 8-hour assessment period and the 3-hour post-dose period, patients taking IRO-A had a lower Drug Liking visual analog scale score compared with the IRO group. All 3 of the primary end points (Drug Liking visual analog scale score, Overall Drug Liking visual analog scale score, and Take Drug Again visual analog scale score) favored the IRO-A group (P<.0001 in each comparison).

Each end point was evaluated on a 0- to 100-point scale, with 0 indicating strong disliking and 100 indicating strong liking. For Drug Liking, the mean IRO-A score was 70.6, while the mean IRO score was 93.4. For Overall Drug Liking, the mean IRO-A score was 47.5, while the mean IRO score was 87.2. For Take Drug Again, the mean IRO-A score was 45.5, while the mean IRO score was 91.2. Of the adverse events reported, none were severe or serious. The authors said that the incidence of adverse events associated with intranasal insufflation was greater in the IRO-A group, including nasal discomfort, nasal congestion, rhinorrhea, throat irritation, increased lacrimation, and facial pain.

They added that no patient had a clinically significant change in laboratory test results or electrocardiogram, but 3 patients had clinically significant out-of-range vital signs when receiving treatment. This study was sponsored by King Pharmaceuticals.