Search

Olanzapine is a commonly used drug in the treatment of schizophrenia, but its clinical application has been restricted by metabolic-related side effects. In order to mitigate the weight gain side effects caused by olanzapine, other drugs with different targets were selected for combined use and evaluated in animal models of schizophrenia. SEP-363856 is a novel psychotropic agent which is under phase III clinical trials for schizophrenia treatment. The aim of the research was to evaluate whether co-administration of olanzapine and SEP-363856 exerts synergistic anti-schizophrenic effects in the apomorphine (APO)-induced climbing test, the MK-801-induced hyperactivity test, and the Morris water maze test, and therefore reduces the weight gain side effects induced by olanzapine. Through isobolographic analysis, the results showed a synergistic interaction in the climbing test; the experimental ED30 (3 mg/kg) was significantly smaller (p < 0.05) than the theoretical ED30 (5 mg/kg). Additionally, such potentiating effects appeared additive in the MK-801 challenge experiment. Co-treatment with an effective dose of olanzapine and a low dose of SEP-363856 reversed MK-801-induced cognitive impairment symptoms in mice. Moreover, combination treatment with olanzapine and SEP-363856 controls sustained weight gain in mice with chronic exposure to olanzapine. These results support further clinical trials to test the effectiveness of co-treatment of olanzapine and SEP-363856 for controlling symptoms and weight gain in patients with schizophrenia during antipsychotic treatments. [ABSTRACT FROM AUTHOR]

To develop safer and potent analgesics, we designed, synthesized, and evaluated a new series of benzylaminofentanyl derivates as bifunctional μ opioid receptor (MOR) and σ 1 receptor (σ 1 R) ligands. Compound 68 (Tao-191) showed desirable MOR agonism (K i = 6.5 nΜ; EC 50 = 48.5 nΜ, E max = 66.3%) and σ 1 R antagonism (K i = 35.7 nM) in vitro , and exerted powerful analgesic effects in the abdominal constriction test (ED 50 = 0.32 mg/kg, in mice), formalin-induced pain test (phase II, ED 50 = 2.26 mg/kg, in rats), and paclitaxel-induced neuropathic pain model (ED 50 = 0.30 mg/kg, in mice). The contributions of MOR and σ 1 R to its antinociceptive effect were verified by combined administration with the MOR antagonist naloxone and the σ 1 R agonist PRE-084, respectively. At equianalgesic doses, compound 68 induced fewer MOR-related side effects—including physical and psychological dependence, respiratory depression, constipation, and acute hyperlocomotion—than fentanyl. The results provide a rationale for further exploration of the action and safety of dual MOR/σ 1 R ligands as a promising avenue for the development of potent and safe analgesics. [Display omitted] • A series of benzylaminofentanyl derivates were synthesized as bifunctional MOR/σ 1 R ligands to develop safer analgesics. • Compound 68 showed desirable MOR agonism (EC 50 = 48.5 nΜ, E max = 66.3%) and σ 1 R antagonism (K i = 35.7 nM) in vitro. • Compound 68 exerted powerful analgesic effects in abdominal constriction test and formalin-induced pain test in rodents. • At equianalgesic doses, compound 68 induced fewer MOR-related side effects than fentanyl in mice. [ABSTRACT FROM AUTHOR]

Opioid analgesics are highly effective painkillers for the treatment of moderate or severe pain, but they are associated with a number of undesirable adverse effects, including the development of tolerance, addiction, constipation and life-threatening respiratory depression. The development of new and safer analgesics with innovative mechanisms of action, which can enhance the efficacy in comparison to available treatments and reduce their side effects, is urgently needed. The sigma-1 receptor (σ 1 R), a unique Ca2+-sensing chaperone protein, is expressed throughout pain-modulating tissues and affects neurotransmission by interacting with different protein partners, including molecular targets that participate in nociceptive signalling, such as the μ-opioid receptor (MOR), N -methyl- d - aspartate receptor (NMDAR) and cannabinoid 1 receptor (CB 1 R). Overwhelming pharmacological and genetic evidence indicates that σ 1 R antagonists induce anti-hypersensitive effects in sensitising pain conditions (e.g. chemically induced, inflammatory and neuropathic pain) and enhance opioid analgesia but not opioid-mediated detrimental effects. It has been suggested that balanced modulation of MORs and σ 1 Rs may improve both the therapeutic efficacy and safety of opioids. This review summarises the functional profiles of ligands with mixed MOR agonist and σ 1 R antagonist activities and highlights their therapeutic potentials for pain management. Dual MOR agonism/σ 1 R antagonism represents a promising avenue for the development of potent and safer analgesics. [Display omitted] • σ 1 R antagonists exhibit anti-hypersensitive effects in sensitising pain conditions. • σ 1 R antagonists enhance opioid analgesia but not opioid-mediated unwanted effects. • Bifunctional MOR and σ 1 R ligands possess wider therapeutic window with fewer adverse effects. • Representative ligands with MOR agonist and σ 1 R antagonist activities were summarised. • Dual MOR-agonism/σ 1 R-antagonism represents a promising avenue for the development of potent and safer analgesics. [ABSTRACT FROM AUTHOR]