Abuse-Deterrent Formulations of Opioid Analgesics

A Review of the Opioid Epidemic: What Do We Do About It?

The opioid epidemic, with its noticeable increase in opioid prescriptions and related misuse, abuse and resultant deaths in the previous 12 years, is a particularly North American phenomenon. Europe, and particularly low- and middle-income countries, appear to be less influenced by this problem. There is undisputable value in using opioids not only in the treatment of acute pain, but in cancer pain as well. However, opioids are progressively being prescribed more and more for chronic non-cancer pain, despite inadequate data on their efficacy. In this paper, we describe the current prevalence of opioid misuse in a number of countries and the rationale for the commencement of opioid therapy. The safe initiation and monitoring of opioid therapy as well as the need for concurrent use of interdisciplinary multimodal therapy is discussed. The possible consequences of long-term use and predictors of high opioid use and overdose are presented. In particular, the management of opioid use disorders and the prevention of opioid abuse and dependence in the young, the old and the pregnant are discussed. Measures to prevent overprescribing and to alleviate risk are described, including the tapering of opioids and the use of opioid deterrents. Finally, the paper looks at the future development of pioneering medications and technologies to potentially treat abuse. In those parts of the world with an opioid epidemic, coroners and medical examiners, private and public health agencies, and agencies that enforce the law need to cooperate in an effort to slow down and reverse the indiscriminate use of prescribing opioids in the long-term for chronic non-cancer pain. Ongoing research is needed to create ways to minimise risks of opioid use, and to provide evidence for effective strategies for treating chronic pain.

Tapentadol Extended Release in the Treatment of Severe Chronic Low Back Pain and Osteoarthritis Pain

Tapentadol is a novel pain reliever with apparently synergistic dual mechanisms of action, capable of addressing both nociceptive and neuropathic components of chronic pain. As an effective analgesic with good tolerability, tapentadol may be appropriate for patients suffering from severe chronic pain associated with low back pain (LBP) or osteoarthritis (OA). Efficacy studies of tapentadol in populations of patients with severe chronic LBP or OA pain suggest that tapentadol is non-inferior to oxycodone. Its tolerability, especially with respect to gastrointestinal (GI) side effects, may be better than that of other strong opioids in clinical trials and analyses of multiple trials. Patient satisfaction with tapentadol extended release for chronic noncancer pain syndromes is good. Although tapentadol has an opioid component with abuse liability, it appears to be a difficult opioid for tampering with less appeal to abusers than other opioids. For patients with severe LBP and OA pain, tapentadol appears to hold promise as a safe, effective therapeutic option.

The Basic Pharmacology of Opioids Informs the Opioid Discourse about Misuse and Abuse: A Review

Morphine and other opioids are widely used to manage moderate to severe acute pain syndromes, such as pain associated with trauma or postoperative pain, and they have been used to manage chronic pain, even chronic nonmalignant pain. However, recent years have seen a renewed recognition of the potential for overuse, misuse, and abuse of opioids. Therefore, prescribing opioids is challenging for healthcare providers in that clinical effectiveness must be balanced against negative outcomes-with the possibility that neither are achieved perfectly. The current discourse about the dual 'epidemics' of under-treatment of legitimate pain and the over-prescription of opioids is clouded by inadequate or inaccurate understanding of opioid drugs and the endogenous pain pathways with which they interact. An understanding of the basic pharmacology of opioids helps inform the clinician and other stakeholders about these simultaneously under- and over-used agents.

Decreased diversion by doctor-shopping for a reformulated extended release oxycodone product (OxyContin)

BACKGROUND

Doctor-shopping (obtaining prescriptions from multiple prescribers/pharmacies) for opioid analgesics produces a supply for diversion and abuse, and represents a major public health issue.

METHODS

An open cohort study assessed changes in doctor-shopping in the U.S. for a brand extended release (ER) oxycodone product (OxyContin) and comparator opioids before (July, 2009 to June, 2010) versus after (January, 2011 to June, 2013) introduction of reformulated brand ER oxycodone with abuse-deterrent properties, using IMS LRx longitudinal data covering >150 million patients and 65% of retail U.S. prescriptions.

RESULTS

After its reformulation, the rate of doctor-shopping decreased 50% (for 2+ prescribers/3+ pharmacies) for brand ER oxycodone, but not for comparators. The largest decreases in rates occurred among young adults (73%), those paying with cash (61%) and those receiving the highest available dose (62%), with a 90% decrease when stratifying by all three characteristics. The magnitude of doctor-shopping reductions increased with increasing number of prescribers/pharmacies (e.g., 75% reduction for ≥2 prescribers/≥4 pharmacies).

CONCLUSIONS

The rate of doctor-shopping for brand ER oxycodone decreased substantially after its reformulation, which did not occur for other prescription opioids. The largest reductions in doctor-shopping occurred with characteristics associated with higher abuse risk such as youth, cash payment and high dose, and with more specific thresholds of doctor-shopping. A higher prescriber and/or pharmacy threshold also increased the magnitude of the decrease, suggesting that it better captured the effect of the reformulation on actual doctor-shoppers.

The Potential Role of an Extended-Release, Abuse-Deterrent Oxycodone/Acetaminophen Fixed-Dose Combination Product for the Treatment of Acute Pain

Acute pain, prevalent as part of postoperative and traumatic pain, is often sub-optimally or inadequately treated. Fixed-dose combination analgesic products that combine a reduced amount of opioid with a nonopioid analgesic such as acetaminophen (paracetamol) in a single tablet offer potential pharmacodynamic and/or pharmacokinetic benefits, and may also result in an opioid-sparing effect. A new analgesic product (XARTEMIS™ XR, Mallinckrodt Brand Pharmaceuticals, Dublin, Ireland) combines oxycodone (7.5 mg) with acetaminophen (325 mg) in an immediate-release/extended-release (ER) formulation that is indicated for the treatment of acute pain. The ER formulation of this product provides stable serum drug concentrations that in this case lasts 12 h. Oxycodone/acetaminophen is a drug combination that offers safe and effective pain relief in a variety of acute pain syndromes such as postoperative pain. The combination formulation allows a smaller amount of oxycodone per tablet and the biphasic-layered matrix of the pill for ER may present obstacles to potential abusers. No opioid is totally abuse resistant, but the lower opioid content and tamper-resistant formulation of this product might discourage abuse. Clinicians must still be mindful of the acetaminophen part of this product in the patient’s overall daily intake (in light of acetaminophen hepatotoxicity). The new product appears to provide an important new choice in the armamentarium against acute pain.