Oral transmucosal fentanyl citrate in cancer pain management: a practical application of nanotechnology

Stress reveals a specific behavioral phenotype for opioid abuse susceptibility

Susceptibility to stress has long been considered important for the development of substance use disorders. Nonetheless, behavioral and physiological responses to stress are highly variable, making it difficult to identify the individuals who are most likely to abuse drugs. In the present study, we employed a comprehensive battery of tests for negative valence behaviors and nociception to identify individuals predisposed to opioid seeking following oral opioid self-administration. Furthermore, we examined how this profile was affected by a history of stress. We observed that mice receiving foot shock stress failed to exhibit a preference for sucrose, showed increased immobility in the forced swim task, and exhibited mechanical hypersensitivity when compared to controls. When considering these behaviors in light of future fentanyl-seeking responses, we observed that heightened mechanical sensitivity corresponded to higher opioid preference in mice with a history of stress, but not controls. Moreover, we were surprised to discover that paradoxically high sucrose preferences predicted fentanyl preference in shock mice, while signs of anhedonia predicted fentanyl preference in controls. Taken together, these results indicate that stress can act as a physiological modulator, shifting profiles of opioid abuse susceptibility depending on an individual's history.

Nanotechnology: A Promising New Paradigm for the Control of Pain

Objective

The objective of this article is to critically review both preclinical and clinical studies that focus on the use of nanotechnology for both acute and chronic pain management, surveying both diagnostic and therapeutic applications. The article also provides information on nanotechnology for pain practitioners, so that they may better understand how this technology works and how it may be applied to their day-to-day clinical practice.

Study Design

Narrative review.

Methods

The Pubmed NCBI and EMBASE databases were utilized to review published reports of in vivo and clinical studies that focus on using nanotechnology for pain management applications in both the acute and chronic pain settings.

Results

Articles were screened by title, abstract, and full article review. They were then analyzed by specific clinical indications, and appropriate data were presented based on a critical analysis of those articles.

Conclusions

As the development of nanomedical applications in acute and chronic pain management continues, medical practitioners should consider their growing potential to enhance the care of patients who are consistently living with pain. Current barriers to implementation include manufacturing scale-up for commercial viability, long-term nanoparticle toxicity considerations, and high cost for successful passage through clinical trials. These challenges will need to be overcome with ongoing translational research efforts in collaboration with industry and government bodies such as the Food and Drug Administration (FDA).

Effect of Modulated Electrohyperthermia on the Pharmacokinetics of Oral Transmucosal Fentanyl Citrate in Healthy Volunteers

PURPOSE

This study aimed to determine whether changes occur in fentanyl absorption and disposition when administered in conjunction with modulated electrohyperthermia (mEHT) treatment.

METHODS

A randomized, single-dose, crossover, open-label study was used to investigate the effect of mEHT on the pharmacokinetic properties of fentanyl in 12 healthy volunteers. The 12 healthy volunteers were each administered a single dose of oral transmucosal fentanyl citrate (OTFC) or a single dose of OTFC with mEHT. mEHT was performed on the abdomen for 1 hour. Blood samples were collected for 24 hours after dosing. The temperature of the abdominal skin surface was assessed before dosing and at 10, 20, and 60 minutes after dosing.

FINDINGS

Geometric mean ratios (ratio of fentanyl with mEHT to fentanyl alone) for the C_max and AUC_0-last were 1.20 (90% CI, 1.09-1.32) and 1.15 (90% CI, 0.99-1.33), respectively. The mean temperature of the abdominal skin surface increased by approximately 4°C.

IMPLICATIONS

There was an increase in the overall exposure to the drug without implications of any clinical significance. OTFC can be administered without limitations in combination with mEHT, and it is not necessary to modify the dosing regimen. cris.nih.go,kr Identifier: KCT0001286.

Development of in vitro models to demonstrate the ability of PecSys®, an in situ nasal gelling technology, to reduce nasal run-off and drip

Many of the increasing number of intranasal products available for either local or systemic action can be considered sub-optimal, most notably where nasal drip or run-off give rise to discomfort/tolerability issues or reduced/variable efficacy. PecSys, an in situ gelling technology, contains low methoxy (LM) pectin which gels due to interaction with calcium ions present in nasal fluid. PecSys is designed to spray readily, only forming a gel on contact with the mucosal surface. The present study employed two in vitro models to confirm that gelling translates into a reduced potential for drip/run-off: (i) Using an inclined TLC plate treated with a simulated nasal electrolyte solution (SNES), mean drip length [±SD, n = 10] was consistently much shorter for PecSys (1.5 ± 0.4 cm) than non-gelling control (5.8 ± 1.6 cm); (ii) When PecSys was sprayed into a human nasal cavity cast model coated with a substrate containing a physiologically relevant concentration of calcium, PecSys solution was retained at the site of initial deposition with minimal redistribution, and no evidence of run-off/drip anteriorly or down the throat. In contrast, non-gelling control was significantly more mobile and consistently redistributed with run-off towards the throat.

Conclusion

In both models PecSys significantly reduced the potential for run-off/drip ensuring that more solution remained at the deposition site. In vivo, this enhancement of retention will provide optimum patient acceptability, modulate drug absorption and maximize the ability of drugs to be absorbed across the nasal mucosa and thus reduce variability in drug delivery.

Perioperative management of the child on long-term opioids

The strategies used to manage children exposed to long-term opioids are extrapolated from adult literature. Opioid consumption during the perioperative period is more than three times that observed in patients not taking chronic opioids. A sparing use of opioids in the perioperative period results in both poor pain management and withdrawal phenomena. The child's pre-existing opioid requirement should be maintained, and acute pain associated with operative procedures should be managed with additional analgesia. This usually comprises short-acting opioids, regional or local anesthesia, and adjuvant therapies. Long-acting opioids, transdermal opioid patches, and implantable pumps can be used to maintain the regular opioid requirement. Intravenous infusion, nurse controlled analgesia, patient-controlled analgesia, or oral formulations are invaluable for supplemental requirements postoperatively. Effective management requires more than simply increasing opioid dose during this time. Collaboration of the child, family, and all teams involved is necessary. While chronic pain or palliative care teams and other staff experienced with the care of children suffering chronic pain may have helpful input, many pediatric hospitals do not have chronic pain teams, and many patients receiving long-term opioids are not palliative. Acute pain services are appropriate to deal with those on long-term opioids in the perioperative setting and do so successfully in many centers. Staff caring for such children in the perioperative period should be aware of the challenges these children face and be educated before surgery about strategies for postoperative management and discharge planning.