Developments in combined analgesic regimens for improved safety in postoperative pain management

Using Clinical-based Discharge Criteria to Discharge Patients After Endoscopy Procedures Under Drug-induced Intravenous Sedation in the Outpatient Care Unit: An Observational Study

PURPOSE

To verify the feasibility of clinical-based discharge (CBD) criteria and to find out the reasons for the delayed discharge of outpatients after endoscopy procedures under drug-induced intravenous sedation.

DESIGN

A prospectively observational study conducted at a tertiary endoscopy center.

METHODS

Medical records were collected from outpatients admitted for endoscopy procedures under drug-induced intravenous sedation from June 1, 2021 to December 30, 2021. Patients were scheduled to discharge at least 30 minutes based on the time-based discharge (TBD) method. Postanesthetic discharge scoring system in the outpatient post-anesthesia care unit (PACU) recorded the time of patients discharged home on the CBD criteria. Postoperative complications were recorded in the PACU and within 24 hours after discharge. Multivariate analysis was applied to identify the factors relating to late discharges.

FINDINGS

10,597 patients were safely and successfully discharged home, and we were informed of no serious emergency or accidental readmissions to the hospital. The mean CBD time (21.77 ± 11.35 minutes) was compared with the TBD time (30 minutes) and actual TBD discharge time (61.56 ± 4.93 minutes), which were statistically significant, without changes in the patient's vital signs (P < .01). Primarily, further univariate and multivariate analyses showed that abdominal pain and fatigue were key factors accountable for delay in PACU discharge (P < .05).

CONCLUSIONS

The study concluded that in patients undergoing ambulatory endoscopy procedures with drug-induced intravenous sedation, discharge times based on physiological scoring systems can efficiently and safely guide ambulatory patient discharge as compared to the traditional TBD method. Postoperative fatigue and pain were the main factors affecting patients discharge associated with a relatively long PACU length of stay.

The Impact of P-Glycoprotein on Opioid Analgesics: What's the Real Meaning in Pain Management and Palliative Care?

Opioids are widely used in cancer and non-cancer pain management. However, many transporters at the blood-brain barrier (BBB), such as P-glycoprotein (P-gp, ABCB1/MDR1), may impair their delivery to the brain, thus leading to opioid tolerance. Nonetheless, opioids may regulate P-gp expression, thus altering the transport of other compounds, namely chemotherapeutic agents, resulting in pharmacoresistance. Other kinds of painkillers (e.g., acetaminophen, dexamethasone) and adjuvant drugs used for neuropathic pain may act as P-gp substrates and modulate its expression, thus making pain management challenging. Inflammatory conditions are also believed to upregulate P-gp. The role of P-gp in drug-drug interactions is currently under investigation, since many P-gp substrates may also act as substrates for the cytochrome P450 enzymes, which metabolize a wide range of xenobiotics and endobiotics. Genetic variability of the ABCB1/MDR1 gene may be accountable for inter-individual variation in opioid-induced analgesia. P-gp also plays a role in the management of opioid-induced adverse effects, such as constipation. Peripherally acting mu-opioid receptors antagonists (PAMORAs), such as naloxegol and naldemedine, are substrates of P-gp, which prevent their penetration in the central nervous system. In our review, we explore the interactions between P-gp and opioidergic drugs, with their implications in clinical practice.

Current and Future Therapeutic Options in Pain Management: Multi-mechanistic Opioids Involving Both MOR and NOP Receptor Activation

Opioids are widely used in chronic pain management, despite major concerns about their risk of adverse events, particularly abuse, misuse, and respiratory depression from overdose. Multi-mechanistic opioids, such as tapentadol and buprenorphine, have been widely studied as a valid alternative to traditional opioids for their safer profile. Special interest was focused on the role of the nociceptin opioid peptide (NOP) receptor in terms of analgesia and improved tolerability. Nociceptin opioid peptide receptor agonists were shown to reinforce the antinociceptive effect of mu opioid receptor (MOR) agonists and modulate some of their adverse effects. Therefore, multi-mechanistic opioids involving both MOR and NOP receptor activation became a major field of pharmaceutical and clinical investigations. Buprenorphine was re-discovered in a new perspective, as an atypical analgesic and as a substitution therapy for opioid use disorders; and buprenorphine derivatives have been tested in animal models of nociceptive and neuropathic pain. Similarly, cebranopadol, a full MOR/NOP receptor agonist, has been clinically evaluated for its potent analgesic efficacy and better tolerability profile, compared with traditional opioids. This review overviews pharmacological mechanisms of the NOP receptor system, including its role in pain management and in the development of opioid tolerance. Clinical data on buprenorphine suggest its role as a safer alternative to traditional opioids, particularly in patients with non-cancer pain; while data on cebranopadol still require phase III study results to approve its introduction on the market. Other bifunctional MOR/NOP receptor ligands, such as BU08028, BU10038, and AT-121, are currently under pharmacological investigations and could represent promising analgesic agents for the future.