Efficacy and Safety of Oxycodone Injection for Relieving Cancer Pain: A Study in Japan Consisting of Two Open Trials for Intravenous and Subcutaneous Administration.

Pure oxycodone injection became increasingly necessary after oral oxycodone was launched in Japan in 2003. However, trials clarifying the efficacy and safety of injection are rare. Therefore, a multicenter open study on injection was designed and carried out in 2010, resulting in the launch of injection therapy in 2012. As published domestic case reports on efficacy already show widespread prescription, this study aimed to provide useful information for cancer pain relief in Japan and other countries. Our oxycodone injection study consisted of two trials, one of intravenous (S#9131) and the other of subcutaneous (S#9132) administration. The minimum required number of enrolled patients suffering cancer pain was determined to be 70 in S#9131 and 20 in S#9132. These studies had the same dose-titration protocol as the main endpoint, i.e., pain relief rate (PRR) defined as the rate of achieving adequate pain control (APC), as in prior oral oxycodone trials in Japan. In S#9131, PRR was 81.4% (95% confidence interval: 70.3-89.7%), therefore, the null hypothesis of PRR<70% was rejected using the binominal one-sided test (p=0.0217). In S#9132, PRR was 73.7% also surpassing 70%. Safety was also assessed in the same way as in prior trials. The majority of adverse effects were moderate or mild and recovered with no sequelae. As shown above, the injection was considered to be effective and safe in cancer pain treatment. The details of these trials, particularly the dose-titration protocol for achieving APC and route switching information, are expected to enhance injection convenience for prescribers.

Breakthrough pain management using fentanyl buccal tablet (FBT) in combination with around-the-clock (ATC) opioids based on the efficacy and safety of FBT, and its relationship with ATC opioids: results from an open-label, multi-center study in Japanese cancer patients with detailed evaluation.

OBJECTIVE: Rapid analgesic onset opioids, particularly fentanyl buccal tablet, is preferable for managing breakthrough pain. The efficacy and safety of fentanyl buccal tablet and its association with around-the-clock opioids needs to be explored with an option of dose adjustments, more closely reflecting administration in clinical practice. The aim of the study was to assess the safety and efficacy of fentanyl buccal tablet in breakthrough pain management in combination with around-the-clock opioids with the dose adjustment option, and explore the dose adjustment's influence on breakthrough pain management using detailed evaluation. METHODS: The 12-week open-label, multi-center study was conducted throughout Japan. Cancer patients aged 20 years or older, experiencing persistent pain controlled with around-the-clock opioids and breakthrough pain with supplemental medications were enrolled. Fentanyl buccal tablet and around-the-clock opioid doses could be adjusted under protocol-specified conditions. Efficacy variables were assessed at each fentanyl buccal tablet administration. Safety was assessed mainly by adverse events. RESULTS: All efficacy variables showed sustained analgesic effect. Nearly half the patients stayed on the same dose; most fentanyl buccal tablet administrations did not require additional supplemental medications. Dose increase of fentanyl buccal tablet and around-the-clock opioids seemed to improve breakthrough pain intensity and frequency, respectively. Fentanyl buccal tablet and around-the-clock opioid doses were not strongly associated. Treatment-related adverse events were all common with opioid treatment and did not increase over time. CONCLUSIONS: Fentanyl buccal tablet can stably and safely manage breakthrough pain in cancer patients with independent dose adjustment based on detailed evaluation of each patient's condition. Breakthrough pain management using fentanyl buccal tablet with around-the-clock opioids at optimal doses may be an important factor in palliative care for cancer patients with breakthrough pain.

Baclofen as an adjuvant analgesic for cancer pain.

PURPOSE: Baclofen is a g-aminobutyric acid receptor agonist commonly used for managing many types of neuropathic pain. The effect of baclofen on cancer pain has not previously been studied. This retrospective study evaluated the efficacy of baclofen in patients with cancer pain. METHODS: We reviewed the medical records of all patients given baclofen orally as an analgesic for cancer at 5 institutions. RESULT: Twenty-five patients received 10 to 40 mg of baclofen for cancer pain relief. Twenty patients have undergone neuropathic pain such as paroxysmal or lancing, sharp, or like an electric shock. Baclofen was effective in 21 of 25 patients and significantly reduced Numeric Rating Scale (pain score, 0-10; P < .0001). Nine patients reported mild adverse events: none of these 9 patients had to discontinue baclofen due to adverse events. CONCLUSION: Our findings suggest that baclofen may be a useful adjuvant analgesic in the treatment of cancer pain.