Naltrexone is a competitive antagonist of μ, δ, and κ opioid receptors. Naltrexone has been investigated for use an as anti-obesity agent in both the general population and in patients with severe mental illness, including schizophrenia. In patients with schizophrenia, however, potential psychotic symptoms due to adverse effects of naltrexone have not been investigated. Our case study, a relevant case report, and some related articles suggest that naltrexone might be associated with the emergence of visual hallucinations, which clinicians should be aware of.
Drug-Related Side Effects and Adverse Reactions ; Hallucinations ; Humans ; Naltrexone ; Narcotic Antagonists ; Receptors, Opioid ; Schizophrenia

The Korean Ministry of Food and Drug Safety has approved three anti-obesity drugs for long-term management in the past decade. In addition, since 2019, bariatric surgery has been financially supported by National Health Insurance Service in Korea. In this review, the mechanisms of action and the clinical implications of the recently approved anti-obesity drugs, lorcaserin, naltrexone/bupropion, and liraglutide are explained. Lorcaserin stimulates proopiomelanocortin (POMC)/cocaine- and amphetamine-regulated transcript (CART) neurons and inhibits neuropeptide Y (NPY)/agouti-related peptide (AgRP) neurons, which results in the activation of melanocortin 3/4 receptors. Naltrexone/bupropion stimulates POMC neurons through bupropion; this stimulation is augmented by blocking the autoinhibitory mechanism of POMC with naltrexone. The hypophagic effect of liraglutide is mediated through the direct activation of POMC/CART neurons and the indirect suppression of NPY/AgRP neurons through γ-aminobutyric acid-dependent signaling, with adjunctive suppression of the mesolimbic dopamine reward system. In addition to liraglutide, another glucagon-like peptide-1 receptor agonist, semaglutide, is expected to be added to the list of anti-obesity drugs in the near future. In patients with obesity and high cardiovascular risk, lorcaserin was considered neutral and liraglutide was considered favorable, whereas inconclusive results were obtained for naltrexone/bupropion.
Anti-Obesity Agents ; Bariatric Surgery ; Bupropion ; Dopamine ; Glucagon-Like Peptide-1 Receptor ; Humans ; Korea ; Liraglutide ; Naltrexone ; National Health Programs ; Neurons ; Neuropeptide Y ; Obesity ; Pro-Opiomelanocortin ; Reward

OBJECTIVES: The current study covers a secondary revision of the guidelines for the pharmacotherapy of schizophrenia issued by the Korean Medication Algorithm for Schizophrenia (KMAP-SCZ) 2001, specifically for co-existing symptoms and antipsychotics-related side-effects in schizophrenia patients. METHODS: An expert consensus regarding the strategies of pharmacotherapy for positive symptoms of schizophrenia, co-existing symptoms of schizophrenia, and side-effect of antipsychotics in patients with schizophrenia was retrieved by responses obtained using a 30-item questionnaire. RESULTS: For the co-existing symptoms, agitation could be treated with oral or intramuscular injection of benzodiazepine or antipsychotics; depressive symptoms with atypical antipsychotics and adjunctive use of antidepressant; obsessive-compulsive symptoms with selective serotonin reuptake inhibitors and antipsychotics other than clozapine and olanzapine; negative symptoms with atypical antipsychotics or antidepressants; higher risk of suicide with clozapine; comorbid substance abuse with use of naltrexone or bupropion/ varenicline, respectively. For the antipsychotics-related side effects, anticholinergics (extrapyramidal symptom), propranolol and benzodiazepine (akathisia), topiramate or metformin (weight gain), change of antipsychotics to aripiprazole (hyperprolactinemia and prolonged QTc) or clozapine (tardive dyskinesia) could be used. CONCLUSION: Updated pharmacotherapy strategies for co-existing symptoms and antipsychotics-related side effects in schizophrenia patients as presented in KMAP-SCZ 2019 could help effective clinical decision making of psychiatrists as a preferable option.
Antidepressive Agents ; Antipsychotic Agents ; Aripiprazole ; Benzodiazepines ; Cholinergic Antagonists ; Clinical Decision-Making ; Clozapine ; Consensus ; Depression ; Dihydroergotamine ; Drug Therapy ; Humans ; Injections, Intramuscular ; Metformin ; Naltrexone ; Propranolol ; Psychiatry ; Schizophrenia ; Serotonin Uptake Inhibitors ; Substance-Related Disorders ; Suicide ; Varenicline

Clinical studies published over the past two decades have consistently demonstrated the therapeutic efficacy and safety of anti-craving medications. To use anti-craving agents more effectively in clinical settings, it is important to set clear treatment goals. Because alcoholic patients have lost control of drinking alcohol, it is recommended to set ‘abstinence’ as a goal rather than ‘controlled drinking’. Indeed, the therapeutic effects of anti-craving medication are higher when abstinence is set as the target. On the other hand, if abstinence is the sole criterion, it is difficult to elicit the motivation of a patient who lacks motivation in clinical practice. In the case of patients who have not yet gained insight, the initial goal might be set to gradually reduce the amount of alcohol consumed and prevent at-risk heavy drinking. Even in this case, anti-craving can help clinically. To increase the effectiveness of anti-craving medications, it is best to start at least four to seven days after the patient has stopped drinking. If the patient has alcohol withdrawal symptoms, they should be treated first.
Alcoholics ; Craving ; Drinking ; Hand ; Humans ; Motivation ; Naltrexone ; Substance Withdrawal Syndrome ; Therapeutic Uses

BACKGROUND: Severe pruritus is a challenging condition, and it is more difficult to deal with in older patients due to their limitations in taking oral medication because of underlying diseases, possible interaction with concurrent medications, and poor general condition. OBJECTIVE: We evaluated the efficacy and safety of naltrexone (Revia®), an opioid antagonist, in elderly patients with severe pruritus that was not easily controlled with conventional antipruritics. METHODS: Eighteen patients were enrolled, with a mean age of 73 years. They additionally received 50 mg of naltrexone per day for an average of 2 months. RESULTS: Using the visual analogue scale, 13 (72.2%) of 18 patients showed a "much improved" condition, reporting more than a 50% decrease in pruritus intensity. Sixteen (88.9%) showed symptomatic improvement, and only 2 (11.1%) had persistent pruritus. Five patients reported side effects including insomnia, fatigue, constipation, and anorexia. However, reactions were either limited to the first 2 weeks or well managed. CONCLUSION: Naltrexone could be an effective and safe alternative treatment option to control severe pruritus in older patients.
Aged ; Anorexia ; Antipruritics ; Constipation ; Fatigue ; Humans ; Naltrexone* ; Pruritus* ; Sleep Initiation and Maintenance Disorders

Autism spectrum disorder (ASD) is characterized by persistent deficits within two core symptom domains: social communication and restricted, repetitive behaviors. Although numerous studies have reported psychopharmacological treatment outcomes for the core symptom domains of ASD, there are not enough studies on fundamental treatments based on the etiological pathology of ASD. Studies on candidate medications related to the pathogenesis of ASD, such as naltrexone and secretin, were conducted, but the results were inconclusive. Oxytocin has been identified as having an important role in maternal behavior and attachment, and it has been recognized as a key factor in the social developmental deficit seen in ASD. Genetic studies have also identified associations between ASD and the oxytocin pathway. As ASD has its onset in infancy, parents are willing to try even experimental or unapproved treatments in an effort to avoid missing the critical period for diagnosis and treatment, which can place their child in an irreversible state. While therapeutic application of oxytocin for ASD is in its early stages, we have concluded that oxytocin would be a promising therapeutic substance via a thorough literature review focusing on the following: the relationship between oxytocin and sociality; single nucleotide polymorphisms as a biological marker of ASD; and validity verification of oxytocin treatment in humans. We also reviewed materials related to the mechanism of oxytocin action that may support its potential application in treating ASD.
Autistic Disorder* ; Child ; Autism Spectrum Disorder* ; Critical Period (Psychology) ; Diagnosis ; Humans ; Maternal Behavior ; Naltrexone ; Oxytocin* ; Parents ; Pathology ; Polymorphism, Single Nucleotide ; Secretin ; Social Change ; Biomarkers

Polydipsia in schizophrenic patients is not uncommon, but a frequently underdiagnosed condition. The etiology of polydipsia remains unclear, and its complications can be life-threatening, while often being difficult to manage it. We report a case of a successfully treated chronic schizophrenic patient with polydipsia. The patient was male, 47-year-old, suffering 27-years of residual schizophrenia who had been consuming more than 10 L of water per day, and is complicated by hyponatremia. He was treated with irbesarten 300 mg and naltrexone 50 mg in the setting of closed ward. He consumed less than 3.5 L of water per day and serum sodium levels seemed to be stable following discharge from the closed ward. We suggest that irbesartan and naltrexone may have beneficial effects for treating polydipsia, and future prospective and well-controlled studies are to be performed.
Humans ; Hyponatremia ; Male ; Middle Aged ; Naltrexone* ; Polydipsia* ; Prospective Studies ; Schizophrenia* ; Sodium ; Water

The purpose of this study was to investigate the differences in subjective acute effects of alcohol and naltrexone among those who prefer spicy food to varying degrees. Acute biphasic alcohol effects scale (BAES), visual analogue scale for craving (VAS-C), blood alcohol concentration (BAC) and food preference scale were measured in 26 men. Repeated measures ANOVA (2 preference groupsx4 time blocks) on the stimulative subscale of BAES revealed a significant group by block interaction in naltrexone condition (N+) (P<0.001), but not in non-naltrexone condition (N-). Furthermore, repeated measures ANOVA (2 drug groupsx4 time blocks) on the stimulative subscale of BAES revealed a significant group by block interaction in strong preference for spicy food (SP) (P<0.001), but not in lesser preference for spicy food (LP). The paired t-test revealed that significant suppression of the stimulative subscale of BAES was observed at 15 min (P<0.001) and 30 min (P<0.001) after drinking when N+ compared with N- in SP. For those who prefer spicy food, the stimulative effect of acute alcohol administration was suppressed by naltrexone. This result suggests that the effect of naltrexone may vary according to spicy food preference.
Adult ; Alcohol Drinking/*adverse effects ; Alcoholism/*drug therapy ; Capsaicin/pharmacology ; Food Preferences/*drug effects ; Humans ; Male ; Naltrexone/adverse effects/*therapeutic use ; Narcotic Antagonists/adverse effects/*therapeutic use ; Questionnaires ; Sensory System Agents/pharmacology ; Young Adult

Sexual violence crime causes severe trauma to victim's family as well as the victim, and its aftereffect which is hard to be healed can last for the entire lifetime. And thus plenty of social cost is incurred due to the crime. It has long been reported that paraphilia is associated with sexual offenders and sexual violence. In this study, the previous foreign data on the psychiatric medication used for sexual offender or paraphilia were summarized for the first time in Korea, and the possibility of medication in Korea was examined. As for the drugs used for sexual offender or paraphilia, SSRI was most frequently reported and besides that, tricyclic antidepressant, antipsychotics, antiepileptic drugs, mirtazapine, and naltrexone were reported.
Anticonvulsants ; Antipsychotic Agents ; Crime ; Criminals ; Humans ; Korea ; Mianserin ; Naltrexone ; Paraphilic Disorders ; Sex Offenses

PURPOSE: Nociceptin/orphanin FQ (N/OFQ) as an endogeneous hexadecapeptide is known to exert antinociceptive effects spinally. The aims of this study were to demonstrate the antinociceptive effects of i.t. N/OFQ and to investigate the possible interaction between N/OFQ and endogenous opioid systems using selective opioid receptor antagonists in rat formalin tests. MATERIALS AND METHODS: I.t. N/OFQ was injected in different doses (1-10 nmol) via a lumbar catheter prior to a 50 microL injection of 5% formalin into the right hindpaw of rats. Flinching responses were measured from 0-10 min (phase I, an initial acute state) and 11-60 min (phase II, a prolonged tonic state). To observe which opioid receptors are involved in the anti-nociceptive effect of i.t. N/OFQ in the rat-formalin tests, naltrindole (5-20 nmol), beta-funaltrexamine (1-10 nmol), and norbinaltorphimine (10 nmol), selective delta-, micro- and kappa-opioid receptor antagonists, respectively, were administered intrathecally 5 min after i.t. N/OFQ. RESULTS: I.t. N/OFQ attenuated the formalin-induced flinching responses in a dose-dependent manner in both phases I and II. I.t. administration of naltrindole and beta-funaltrexamine dose-dependently reversed the N/OFQ-induced attenuation of flinching responses in both phases; however, norbinaltorphimine did not. CONCLUSION: I.t. N/OFQ exerted an antinociceptive effect in both phases of the rat-formalin test through the nociceptin opioid peptide receptor. In addition, the results suggested that delta- and micro-opioid receptors, but not kappa-opioid receptors, are involved in the antinociceptive effects of N/OFQ in the spinal cord of rats.
Analgesics/administration & dosage/*pharmacology ; Animals ; Formaldehyde/toxicity ; Injections, Spinal ; Male ; Naltrexone/administration & dosage/analogs & derivatives/pharmacology ; Narcotic Antagonists/administration & dosage/*pharmacology ; Opioid Peptides/administration & dosage/*pharmacology ; Pain Measurement ; Rats ; Rats, Sprague-Dawley ; Receptors, Opioid/*agonists/drug effects