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Background Oliceridine is a biased ligand at the μ-opioid receptor recently approved for the treatment of acute pain. In a thorough QT study, corrected QT (QTc) prolongation displayed peaks at 2.5 and 60 minutes after a supratherapeutic dose. The mean plasma concentration peaked at 5 minutes, declining rapidly thereafter. Objective The purpose of this study was to examine the basis for the delayed effect of oliceridine to prolong the QTc interval. Methods Repolarization parameters and tissue accumulation of oliceridine were evaluated in rabbit left ventricular wedge preparations over a period of 5 hours. The effects of oliceridine on ion channel currents were evaluated in human embryonic kidney and Chinese hamster ovary cells. Quinidine was used as a control. Results Oliceridine and quinidine produced a progressive prolongation of the QTc interval and action potential duration over a period of 5 hours, paralleling slow progressive tissue uptake of the drugs. Oliceridine caused modest prolongation of these parameters, whereas quinidine produced a prominent prolongation of action potential duration and QTc interval as well as development of early afterdepolarization (after 2 hours), resulting in a high torsades de pointes score. The 50% inhibitory concentration values for the oliceridine inhibition of the rapidly activating delayed rectifier current (human ether a-go-go current) and late sodium channel current were 2.2 and 3.45 μM when assessed after traditional acute exposure but much lower after 3 hours of drug exposure. Conclusion Our findings suggest that a gradual increase of intracellular access of drugs to the hERG channels as a result of their intracellular uptake and accumulation can significantly delay effects on repolarization, thus confounding the assessment of QT interval prolongation and arrhythmic risk when studied acutely. The multi-ion channel effects of oliceridine, late sodium channel current inhibition in particular, point to a low risk of devloping torsades de pointes.

Background. Oliceridine, an investigational IV opioid, is a first-in-class G-protein selective agonist at the μ-opioid receptor. The G-protein selectivity results in potent analgesia with less recruitment of β-arrestin, a signaling pathway associated with opioid-related adverse events (ORAEs). In randomized controlled studies in both hard and soft tissue models yielding surgical pain, oliceridine provided effective analgesia with a potential for an improved safety and tolerability profile at equianalgesic doses to morphine. The phase 3, open-label, single-arm, multicenter ATHENA trial demonstrated the safety, tolerability, and effectiveness of oliceridine in moderate to severe acute pain in a broad range of patients undergoing surgery or with painful medical conditions warranting use of an IV opioid. This retrospective, observational chart review study compared respiratory depression events associated with oliceridine administration as found in the ATHENA trial to a control cohort treated with conventional opioids. Methods. Patients at 18 years of age or older, who underwent colorectal, orthopedic, cardiothoracic, bariatric, or general surgeries between June 2015 and May 2017 in 11 sites participating in the ATHENA trial who received postoperative analgesia either with IV oliceridine or with IV conventional opioids (e.g., morphine alone or in combination with other opioids) (CO cohort); and had a hospital stay >48 hours, were included in this retrospective analysis. Data from the ATHENA trial was used for the oliceridine cohort; and additional baseline characteristics were collected from medical charts. Data from medical charts were collected for all CO cohort patients. The two cohorts were balanced using an inverse probability weighting method. The primary outcome was the incidence of operationally defined opioid-induced respiratory depression (OIRD) in the two cohorts. Secondary outcomes included between-group comparison of the incidence of OIRD events among a subset of high-risk patients. Results. OIRD was significantly less in the oliceridine cohort compared to the CO cohort (8.0% vs. 30.7%; odds ratio: 0.139) (95% confidence interval [CI] 0.09–0.22; P < 0.0001 ). Likewise, the incidence of OIRD was lower among high-risk patients in the oliceridine cohort (9.1% vs. 34.7%; odds ratio: 0.136) (95% CI [0.09–0.22]; P < 0.0001 ) compared to the CO cohort. Conclusion. In this retrospective chart review study, patients receiving IV oliceridine for moderate to severe acute pain demonstrated a lower incidence of treatment emergent OIRD compared to patients who were treated with IV morphine either alone or with concomitant administration of other opioids.

Background Although transcranial magnetic stimulation (TMS) can be an effective acute antidepressant treatment, few studies systematically examine persistence of benefit. Objective We assessed the durability of antidepressant effect after acute response to TMS in patients with major depressive disorder (MDD) using protocol-specified maintenance antidepressant monotherapy. Methods Three hundred one patients were randomly assigned to active or sham TMS in a 6-week, controlled trial. Nonresponders could enroll in a second, 6-week, open-label study. Patients who met criteria for partial response (i.e., >25% decrease from the baseline HAMD 17) during either the sham-controlled or open-label study (n = 142) were tapered off TMS over 3 weeks, while simultaneously starting maintenance antidepressant monotherapy. Patients were then followed for 24 weeks in a naturalistic follow-up study examining the long-term durability of TMS. During this durability study, TMS was readministered if patients met prespecified criteria for symptom worsening (i.e., a change of at least one point on the CGI-S scale for 2 consecutive weeks). Relapse was the primary outcome measure. Results Ten of 99 (10%; Kaplan-Meier survival estimate=12.9%) patients relapsed . Thirty-eight (38.4%) patients met criteria for symptom worsening and 32/38 (84.2%) reachieved symptomatic benefit with adjunctive TMS. Safety and tolerability were similar to acute TMS monotherapy. Conclusions These initial data suggest that the therapeutic effects of TMS are durable and that TMS may be successfully used as an intermittent rescue strategy to preclude impending relapse.

Arginine-vasopressin (AVP) is regarded as a potent stimulator of pituitary adrenocorticotropin (ACTH) secretion and participates therefore in the regulation of the hypothalamic-pituitary-adrenal (HPA) axis function in concert with the physiological activator of the axis, hypothalamic corticotropin-releasing hormone (CRH). We examined the effects of AVP and/or three synthetic V1b receptor antagonists on the activity of the HPA axis in vivo and in vitro in the rat. AVP was injected intravenously to Sprague-Dawley rats (1 microgram/rat) through an indwelling jugular catheter. AVP stimulated ACTH release, with maximal effect 10 min after injection. Intravenous injection of three V1b antagonists, [1-(beta-mercapto-beta,beta-cyclopentamethylenepropionic acid), 2-O-ethyltyrosine, 4-valine] arginine vasopressin (d(CH2)5[Tyr(Et2)]VAVP (WK 1-1), 9-desglycine[1-(beta-mercapto-beta,beta- cyclopentamethylenepropionic acid), 2-O-ethyltyrosine, 4-valine] arginine vasopressin desGly9d(CH2)5 [Tyr(Et2)]-VAVP (WK 3-6), and 9-desglycine [1-(beta-mercapto-beta,beta- cyclopentamethylenepropionic acid),2-D-(O-ethyl)tyrosine, 4-valine ] arginine vasopressin des Gly9d(CH2)5[D-Tyr(Et2)]VAVP (AO 3-21), prevented AVP-stimulated ACTH secretion. Explanted rat hypothalami incubated in vitro with graded concentrations of AVP (10(-14)-10(-5) M) secreted immunoreactive CRH (iCRH) in a concentration-dependent fashion. Maximal stimulatory effect occurred at the concentration of 10(-6) M. Incubation of hypothalami with WK 1-1, WK3-6, or AO 3-21 (10(-6) M) prevented AVP-stimulated iCRH secretion. Results suggest that AVP plays a relevant, multiple role in the activation of the HPA axis in the rat.(ABSTRACT TRUNCATED AT 250 WORDS)