Urothelial toxicity of esketamine in the treatment of depression

Effect of esketamine on serum neurotransmitters in patients with postpartum depression: a randomized controlled trial

BACKGROUND

The development of postpartum depression has been linked to fluctuations in the levels of neurotransmitters in the human body, such as 5-hydroxytryptamine (5-HT), dopamine (DA), noradrenaline (Norepinephrine, NE), and brain derived neurotrophic factor (BDNF). Research has indicated that the antidepressant effect of esketamine are mediated by monoamine transmitters and neurotrophic factors. Therefore, we postulate that intravenous administration of esketamine in patients with postpartum depression may alter the serum concentrations of these neurotransmitters.

METHODS

Three hundred fifteen patients with postpartum depression were selected and divided into two groups based on randomized numerical expression: esketamine (E) group (0. 25 mg/kg esketamine) and control (C) group (a same volume of 0.9% saline), all the drugs were pumped for 40 min. After the end of drug pumping, all patients were continuously observed for 2 h. Changes in serum levels of 5-HT, DA, NE, BDNF were recorded before drug administration and on the 3rd day after drug administration. The scores of Edinburgh Postnatal Depression Scale (EPDS) were calculated before drug administration, and on the 3rd day and on the 30th day after drug administration. Dizziness, headache, nausea, vomiting, drowsiness, and feeling of detachment occurred were recorded within 2 h after drug administration.

RESULTS

Before drug administration, the serum concentrations of 5-HT,DA,BDNF,NE in Group E and Group C were namely (0. 91 ± 0. 19 vs. 0. 98 ± 0. 21, P = 0. 181), (2. 38 ± 0. 35 vs. 2. 32 ± 0. 32, P = 0. 491), (3. 07 ± 0. 89 vs 3. 02 ± 0. 88, P = 0. 828), (39. 79 ± 7. 78 vs 41. 34 ± 10. 03, P = 0. 506). On the third day post-medication, the serum concentrations of 5-HT,DA,BDNF,NE in Group E and Group C were namely (1. 42 ± 0. 35 vs. 0. 96 ± 0. 24, P < 0. 001), (3. 99 ± 0. 17 vs. 2. 41 ± 0. 28, P < 0. 001),(5. 45 ± 0. 81 vs 3. 22 ± 0. 76, P < 0. 001),(44. 36 ± 9. 98 vs 40. 69 ± 11. 75, P = 0. 198). Before medication, the EPDS scores were (16. 15 ± 3. 02 vs 17. 85 ± 3. 89, P = 0. 064). on the third day after medication, the Group E had significantly reduced scores (12. 98 ± 2. 39 vs 16. 73 ± 3. 52, P < 0. 001). On the 30rd day after medication, EPDS scores between the two groups were (16. 34 ± 3. 43 vs 16. 91 ± 4. 02, p = 0. 203). Within 2 h of medication, the rate of adverse events was similar between the two groups.

CONCLUSIONS

Small doses of esketamine can increase the serum concentration of 5-HT,DA,BDNF, and in the short term, decrease EPDS scores, and improve postpartum depressive symptoms.

TRIAL REGISTRATION

Retrospectively registered in the Chinese Clinical Trial Registry (ChiCTR2300078343, 2023/12/05).

A randomized controlled pilot study of daily intravenous ketamine over three days for treatment-resistant depression

BACKGROUND

Studies have confirmed the rapid antidepressant action of ketamine in depressive episodes. Nevertheless, a standardized procedure for the delivery of ketamine infusion in individuals suffering from treatment-resistant depression, particularly in terms of infusion frequency and total dosage, remains undetermined. In addition, an efficacious ketamine regimen for persistent pain management involved a continuous 10-day infusion period with no notable adverse effects. Consequently, the primary objective of this study was to evaluate the antidepressant capacity of consecutive ketamine infusions spanning over three successive days, the duration of therapeutic response, and the overall safety profile of the treatment.

METHODS

In this randomized controlled trial, participants aged 18-64 with treatment-resistant depression were randomized to receive either intravenous ketamine or midazolam (used as an active placebo) for 40 min daily over three consecutive days. Statistical analysis using repeated measures ANOVA was employed to assess the changes in the total score of the Montgomery-Åsberg Depression Rating Scale (MADRS) and the clinical global impression-Severity from the initial assessment to 10 and 31 days post-infusion. Additionally, the duration of response and remission was evaluated using Kaplan-Meier survival analysis.

RESULTS

Out of 33 randomized participants, 20 underwent the treatment as planned. By day 10th, the ketamine group had a mean reduction in MADRS score of 12.55 (95% CI = 6.70-18.09), whereas the midazolam group had a decrease of 17.22 (95% CI = 11.09-23.36). This pattern continued to day 31, with ketamine showing a mean score decrease of 13.73 (95% CI = 7.54-19.91) and midazolam a fall of 12.44 (95% CI = 5.61-19.28). Both treatments were well tolerated, with dissociative symptoms in the ketamine group being temporary and ceasing by the end of each infusion.

CONCLUSION

Intravenous ketamine given for three consecutive days did not show a notable antidepressant advantage when compared to the active placebo midazolam, highlighting the need for further research into effective treatments schedules for treatment-resistant depression.

TRIAL REGISTRATION

NCT05026203, ClinicalTrials.gov, registered on 24/08/2021.

Beyond therapeutic potential: a systematic investigation of ketamine misuse in patients with depressive disorders

Ketamine, a pharmacological agent that acts as an antagonist of the N-methyl-D-aspartate (NMDA) receptor, has garnered considerable interest because of its notable and expeditious antidepressant properties observed in individuals diagnosed with major depressive disorder (MDD) who exhibit resistance to conventional therapeutic interventions. A comprehensive and rigorous systematic review was undertaken to evaluate the prevalence of ketamine abuse undergoing ketamine treatment for depressive disorders. A comprehensive search was conducted across the electronic databases to identify pertinent studies published between 2021 and 2023. The present investigation incorporated a comprehensive range of studies encompassing the abuse or misuse of ketamine, including case reports, observational studies, and clinical trials. Data extraction and quality assessment were conducted in accordance with predetermined criteria. The findings of this systematic review demonstrate the importance of monitoring and addressing ketamine abuse in patients receiving ketamine treatment for depressive disorders like MDD. The wide range of reported prevalence rates highlights the need for standardized criteria and measures for defining and assessing ketamine abuse. This study presents a significant contribution to the field by introducing a novel screening questionnaire and assessment algorithm designed to identify and evaluate ketamine misuse among major depressive disorder (MDD) patients undergoing ketamine treatment. This innovative tool holds the potential to enhance clinical practice by providing healthcare professionals with a standardized approach to promptly detect and address ketamine misuse. The integration of this screening tool into routine care protocols can facilitate more effective monitoring and management of ketamine misuse in this population, ultimately leading to improved patient outcomes and safety.

Ketamine cystitis following ketamine therapy for treatment-resistant depression - case report

BACKGROUND

Ketamine is a novel and exciting putative antidepressant medication for patients with treatment-resistant depression. A complication commonly seen in frequent and heavy recreational use of ketamine is ulcerative cystitis, which presents with lower urinary tract symptoms (LUTS) and upper renal tract damage and can be seen in over 25% of regular users. Although Ketamine-induced cystitis (KIC) is a recognised complication in recreational use of ketamine, its occurrence in therapeutic use of ketamine in depression has so far not been reported. The exact pathogenesis of KIC is currently unknown, making treatment and prevention advice much more difficult. Early diagnosis of KIC and immediate cessation of ketamine has been shown to improve adverse urinary tract symptoms and prevent further damage.

CASE PRESENTATION

We present a case of a 28-year-old female who was started on ketamine treatment for depression, and who then developed symptoms of KIC, which was confirmed by urine microscopy, culture and analysis.

CONCLUSIONS

To our knowledge, this is the first reported case of KIC in a patient receiving treatment-dose ketamine as part of their antidepressant therapy.

The Psychedelic Future of Post-Traumatic Stress Disorder Treatment

Post-traumatic stress disorder (PTSD) is a mental health condition that can occur following exposure to a traumatic experience. An estimated 12 million U.S. adults are presently affected by this disorder. Current treatments include psychological therapies (e.g., exposure-based interventions) and pharmacological treatments (e.g., selective serotonin reuptake inhibitors (SSRIs)). However, a significant proportion of patients receiving standard-of-care therapies for PTSD remain symptomatic, and new approaches for this and other trauma-related mental health conditions are greatly needed. Psychedelic compounds that alter cognition, perception, and mood are currently being examined for their efficacy in treating PTSD despite their current status as Drug Enforcement Administration (DEA)- scheduled substances. Initial clinical trials have demonstrated the potential value of psychedelicassisted therapy to treat PTSD and other psychiatric disorders. In this comprehensive review, we summarize the state of the science of PTSD clinical care, including current treatments and their shortcomings. We review clinical studies of psychedelic interventions to treat PTSD, trauma-related disorders, and common comorbidities. The classic psychedelics psilocybin, lysergic acid diethylamide (LSD), and N,N-dimethyltryptamine (DMT) and DMT-containing ayahuasca, as well as the entactogen 3,4-methylenedioxymethamphetamine (MDMA) and the dissociative anesthetic ketamine, are reviewed. For each drug, we present the history of use, psychological and somatic effects, pharmacology, and safety profile. The rationale and proposed mechanisms for use in treating PTSD and traumarelated disorders are discussed. This review concludes with an in-depth consideration of future directions for the psychiatric applications of psychedelics to maximize therapeutic benefit and minimize risk in individuals and communities impacted by trauma-related conditions.

Esketamine-A quick-acting novel antidepressant without the disadvantages of ketamine

Esketamine, which is an S-enantiomer of ketamine, is better than conventional antidepressants and even better than R-ketamine. This article discusses the mechanism of action of Esketamine, how different it is from other antidepressants, its side effect profile, indications for use, various routes of administration and the review of existing literature on Esketamine.

Effects of esketamine on analgesia and postpartum depression after cesarean section: A randomized, double-blinded controlled trial

BACKGROUND

The aim of this randomized double-blind placebo controlled clinical trial was to investigate the effects of different doses of esketamine combined with sufentanil for postoperative intravenous controlled analgesia after cesarean section and the incidence of postpartum depression.

METHODS

One hundred and sixty patients undergoing elective cesarean section, with a singleton term pregnancy and American Society of Anesthesiologists physical status II were selected. All patients were treated by a combined epidural with spinal anesthesia. They were randomly divided into 4 groups according to patient controlled intravenous analgesia formula. The consumption of sufentanil, times of effective press and remediate analgesia at 48 hours after cesarean section, incidence of postpartum depression (PPD) at 1 week and 6 weeks after the operation were recorded.

RESULTS

Comparison of cumulated dosage of sufentanil, times of effective press and rescue analgesia at 48 hours after operation: Group H was significantly lower than Group M, Group L, and Group C (P < .05), Group M significantly lower than group L and Group C (P < .05), and Group L significantly lower than Group C (P < .05). Comparison of the incidence of PPD at 1 week and 6 weeks later: Group H was significantly lower than Group M, Group L, and Group C (P < .01), Group M significantly lower than Group L and Group C (P < .01) and Group L significantly lower than Group C (P < .01). Compared with Group C, the incidence of nausea and vomiting was significantly reduced in Group H, Group M, and Group L (P < .05).

CONCLUSION

Esketamine combined with sufentanil used for patient controlled intravenous analgesia after elective cesarean section can reduce the consumption of sufentanil, improve postoperative analgesia, decrease the incidence of PPD at 1 week and 6 weeks and postoperative nausea and vomiting.

The antidepressant effect and safety of non-intranasal esketamine: A systematic review

BACKGROUND

The introduction of esketamine into the field of psychiatry comes on the heels of excitement from studies on racemic ketamine. While the intranasal route has been the most studied to date, other modes of administration of esketamine may also be of interest in the management of depression.

AIMS

To systematically review the literature on non-intranasal esketamine for depression in terms of its antidepressant effect and safety.

METHODS

We searched PubMed, Embase, the Cochrane Library, and Google Scholar from inception up to February 2021. Search terms included a combination of Medical Subject Headings and text words indicative of esketamine and depression. We selected both controlled and uncontrolled studies examining non-intranasal esketamine for the treatment of depression.

RESULTS

We identified four randomized controlled trials (RCTs) on intravenous esketamine and 15 open-label studies on intravenous (n = 80), subcutaneous (n = 73), and oral (n = 5) esketamine. We found intravenous, subcutaneous, and possibly oral administration of esketamine to be effective in reducing depressive symptoms in most patients with major depressive disorder, bipolar depression, and (severe) treatment-resistant depression. Clinical response to repeated administration of esketamine persisted over the course of treatment. Esketamine was well tolerated by most patients, but open-label data indicate marked psychotomimetic symptoms in exceptional cases. The overall quality of the controlled studies was considered high, the overall quality of the uncontrolled studies low to moderate.

CONCLUSIONS

Intravenous, subcutaneous, and possibly oral esketamine may offer an effective and safe addition to the depression treatment armamentarium. However, as most included studies lacked a control group and had small sample sizes, the quality of our results is limited. Different types and formulations of ketamine remain to be compared directly.

Key considerations for the use of ketamine and esketamine for the treatment of depression: focusing on administration, safety, and tolerability

INTRODUCTION

Racemic ketamine, a derivative of phencyclidine, has been used as a dissociative anesthetic since 1970. In 2000, the first randomized controlled trial showed a rapid relief of depressive symptoms. Since then, intravenous ketamine and intranasal S-ketamine have been validated for the treatment of depression and suicidal ideation following dose-response and double-blind placebo-controlled clinical trials. In clinical practice, after dose titration and with repeated treatments, patients may experience approximately 2-3 weeks of symptomatic relief from depression.

AREAS COVERED

Areas covered in this narrative review include mechanism of action, dosing, safety, and tolerability. Some attention is paid to the possibility of R-ketamine as a future antidepressant.

EXPERT OPINION

We recommend further investigation into treatment dosing and frequency strategies as well as approaches that prolong the therapeutic effects. The current fixed dosing of esketamine for obese individuals may be insufficient. Additional investigation into co-administration with somatic and neuromodulation treatments needs investigation. Finally, continuing to monitor research subjects and patients long-term for the emergence of adverse effects on cognition or other organ systems is critical.

Long-term safety of ketamine and esketamine in treatment of depression

INTRODUCTION

Ketamine is an NMDA receptor antagonist that can produce rapid-acting antidepressant effects. Esketamine (Spravato), the S-enantiomer of racemic ketamine, was approved by the FDA for treatment-resistant depression in 2019. Here we review what is known about the long-term safety of both racemic ketamine and esketamine as therapies for psychiatric disorders.

AREAS COVERED

In this article, we conducted a safety review of ketamine and esketamine. In looking at ketamine and esketamine long-term safety effects, we considered data available from experimental studies and several phase-three clinical trials.

EXPERT OPINION

Based on available data, the most common side effects of ketamine/esketamine are generally transient, mild, and self-limited. These include dissociation, nausea, headache, elevated heart rate, and blood pressure. Treatment with esketamine may lead to an increased risk of lower urinary tract symptoms, such as dysuria or urgency. However, severe bladder pathology has not been reported among patients receiving doses of esketamine/ketamine in line with prescribing guidelines for depression. There is considerable data that ketamine at high doses can lead to long-term impairments in cognition. However, the esketamine clinical trials found that cognition generally remains stable or improves over time, suggesting that when used appropriately, there is no increased risk of cognitive impairment.

Research advances in the clinical application of esketamine

Esketamine is dextrorotatory ketamine, which is an enantiomer of ketamine. Compared with ketamine, it has the advantages of a fast metabolism, fewer side effects, and strong pharmacological effects, so it is more suitable for clinical use. Esketamine has a powerful analgesic effect and has little effect on breathing. It has a wide range of applications in the fields of pediatric anesthesia, conscious sedation anesthesia, and emergency analgesia. In addition, it is also used for pain that is difficult to relieve with conventional drugs and to prevent postoperative pain. Various routes of administration are also suitable for patients who need short-term analgesia and sedation. As a drug, esketamine inevitably brings some side effects when it is used clinically. In this article, by introducing the mechanism of action and pharmacological characteristics of esketamine, its clinical application is reviewed, and it provides a reference for the more reasonable and safe clinical application of esketamine.

[Practical aspects of ketamine treatment-Safety, combination treatment and comorbidities]

BACKGROUND

Although multiple studies and meta-analyses have documented the rapid antidepressive efficacy of ketamine, there are numerous questions regarding the practical use in the clinical routine that are still unanswered.

OBJECTIVE

Based on personal clinical experience, by comparison and supplementation of the current data situation, answers are given to questions regarding the practical use of ketamine for depression that have not yet been satisfactorily clarified.

MATERIAL AND METHODS

The clinical experiences with antidepressive treatment using ketamine over more than 5 years were evaluated with respect to the questions at hand. This was followed by a qualitative comparison of these results with those of a narrative literature search.

RESULTS

A total of 72 patients (unipolar depression n = 53, bipolar depression n = 16, schizoaffective depression n = 3) were included in the analysis of this cohort. A statistically significant reduction of depressive symptoms and suicidal ideation after S-ketamine treatment was found. Of the patients 61% suffered from at least one secondary diagnosis. A dose of 0.5 mg/kg body weight of S‑ketamine at a frequency of three times per week was shown to be effective. The treatment appears to be safe with respect to urotoxic side effects, combination treatment with tranylcypromine and in comorbid posttraumatic stress disorder.

CONCLUSION

Ketamine appears to be a safe and effective option for the treatment of unipolar and bipolar depression.

Non-parenteral Ketamine for Depression: A Practical Discussion on Addiction Potential and Recommendations for Judicious Prescribing

Intravenous (IV) ketamine is increasingly used off-label at subanesthetic doses for its rapid antidepressant effect, and intranasal (IN) esketamine has been recently approved in several countries for treating depression. The clinical utility of these treatments is limited by a paucity of publicly funded IV ketamine and IN esketamine programs and cost barriers to private treatment programs, as well as the drug cost for IN esketamine itself, which makes generic ketamine alternatives an attractive option. Though evidence is limited, use of non-parenteral racemic ketamine formulations (oral, sublingual, and IN) may offer more realistic access in less rigidly supervised settings, both for acute and maintenance treatment in select cases. However, the psychiatric literature has repeatedly cautioned on the addictive potential of ketamine and raised caution for both less supervised and longer-term use of ketamine. To date, these concerns have not been discussed in view of available evidence, nor have they been discussed within a broader clinical context. This paper examines the available relevant literature and suggests that ketamine misuse risks appear not dissimilar to those of other well-established and commonly prescribed agents with abuse potential, such as stimulants or benzodiazepines. As such, ketamine prescribing should be considered in a similar risk/benefit context to balance patient access and need for treatment with concern for potential substance misuse. Our consortium of mood disorder specialists with significant ketamine prescribing experience considers prescribing of non-parenteral ketamine a reasonable clinical treatment option in select cases of treatment-resistant depression. This paper outlines where this may be appropriate and makes practical recommendations for clinicians in judicious prescribing of non-parenteral ketamine.

Ketamine for Depression: Advances in Clinical Treatment, Rapid Antidepressant Mechanisms of Action, and a Contrast with Serotonergic Psychedelics

The approval of ketamine for treatment-resistant depression has created a model for a novel class of rapid-acting glutamatergic antidepressants. Recent research into other novel rapid-acting antidepressants - most notably serotonergic psychedelics (SPs) - has also proven promising. Presently, the mechanisms of action of these substances are under investigation to improve these novel treatments, which also exhibit considerable side effects such as dissociation. This chapter lays out the historical development of ketamine as an antidepressant, outlines its efficacy and safety profile, reviews the evidence for ketamine's molecular mechanism of action, and compares it to the proposed mechanism of SPs. The evidence suggests that although ketamine and SPs act on distinct primary targets, both may lead to rapid restoration of synaptic deficits and downstream network reconfiguration. In both classes of drugs, a glutamate surge activates α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) throughput and increases in brain-derived neurotrophic factor (BDNF) levels. Taken together, these novel antidepressant mechanisms may serve as a framework to explain the rapid and sustained antidepressant effects of ketamine and may be crucial for developing new rapid-acting antidepressants with an improved side effect profile.

The rapid anti-suicidal ideation effect of ketamine: A systematic review

In many countries suicide rates have been trending upwards for close to twenty years-presenting a public health crisis. Most suicide attempts and deaths are associated with psychiatric illness, usually a depressive disorder. Subanesthetic ketamine is the only FDA-approved antidepressant that works in hours not weeks-thus potentially transforming treatment of suicidal patients. We reviewed all randomized controlled trials of the effect of ketamine on suicidal ideation to determine if ketamine rapidly reduces suicidal ideation [SI] in depressed patients and how long the benefit persists after one dose and if the route of administration or dose affects the outcome. A systematic review was conducted as per PRISMA [preferred reporting items for systematic reviews and meta-analyses] criteria. PubMed search inclusive of "ketamine" and "suicide" yielded 358 results. Papers (N = 354) were then read by at least two authors, identifying 12 meeting eligibility requirements and eleven RCTs examining whether ketamine treatment ameliorated SI. Four of five RCTs examined racemic ketamine (0.5 mg/kg) given intravenously and found an advantage for ketamine over control for rapid reduction in SI in acutely depressed patients. Two studies examined intranasal esketamine in depressed suicidal patients and found no advantage over saline. One study examined outcome six weeks after a single intravenous dose of ketamine and found benefit for SI sustained relative to 24 h post-dose. Further research is warranted into: optimal dosing strategy, including number and frequency; and long-term efficacy and safety. Ultimately, it remains to be shown that ketamine's benefit for SI translates into prevention of suicidal behavior.

Ready for a "breakthrough" with ketamine? A look at recent pharmacological insights!

PURPOSE OF REVIEW

To update pharmacological insights on ketamine integrating information from different disciplines for developing steps to "breakthrough" approaches in clinical challenges.

RECENT FINDINGS

Pharmacokinetic/pharmacodynamic (PK/PD) models have incorporated recirculation, ketamine metabolites, drug-drug interaction, and covariates such as age. Ketamine-induced relief from treatment-resistant depression has been explained by "disinhibition" of gamma-aminobutyric acid-ergic interneurons and synaptogenic mechanisms requiring neurotrophic signals. Neuroimaging/electroencephalographic investigations have shown an increase in gamma spectral power in healthy volunteers and patients with depression, but also opposite changes in functional network connectivity after subanesthetic ketamine. Volunteer data may not be transferable to clinical conditions. Altered states of consciousness induced by subanesthetic ketamine have been described by disruption of resisting-state functional networks and frontoparietal connectivity with preservation of multisensory and sensor-motor networks. This has been interpreted as a "disconnected consciousness".

SUMMARY

More precise PK/PD models may improve the ketamine use regimen. The findings from research on depression are an important discovery because ketamine's impact on neuronal plasticity and synaptogenesis in human brain disease has directly been documented. Psychic adverse effects with subanesthetic ketamine are related to a "disconnected consciousness". Overall, progress has been made, but the "breakthrough" still has to come.

Synthesizing the Evidence for Ketamine and Esketamine in Treatment-Resistant Depression: An International Expert Opinion on the Available Evidence and Implementation

Replicated international studies have underscored the human and societal costs associated with major depressive disorder. Despite the proven efficacy of monoamine-based antidepressants in major depression, the majority of treated individuals fail to achieve full syndromal and functional recovery with the index and subsequent pharmacological treatments. Ketamine and esketamine represent pharmacologically novel treatment avenues for adults with treatment-resistant depression. In addition to providing hope to affected persons, these agents represent the first non-monoaminergic agents with proven rapid-onset efficacy in major depressive disorder. Nevertheless, concerns remain about the safety and tolerability of ketamine and esketamine in mood disorders. Moreover, there is uncertainty about the appropriate position of these agents in treatment algorithms, their comparative effectiveness, and the appropriate setting, infrastructure, and personnel required for their competent and safe implementation. In this article, an international group of mood disorder experts provides a synthesis of the literature with respect to the efficacy, safety, and tolerability of ketamine and esketamine in adults with treatment-resistant depression. The authors also provide guidance for the implementation of these agents in clinical practice, with particular attention to practice parameters at point of care. Areas of consensus and future research vistas are discussed.

Ketamine-induced urological toxicity: potential mechanisms and translation for adults with mood disorders receiving ketamine treatment

Intravenous (IV) ketamine has been shown to have rapid and robust antidepressant effects in adults with treatment-resistant depression (TRD). Urological toxicity has been observed in chronic ketamine abusers as evidenced by dysuria, urgency, and hematuria. The foregoing observation provides the basis for evaluating whether ketamine-induced urological toxicity (KIUT) is associated with sub-anesthetic doses of ketamine (0.5-1.0 mg/kg) in adults with mood disorders. The overarching objective of this article is to identify potential mechanisms of KIUT which appears to be dose and frequency dependent. Available research indicates that high-frequency ketamine is associated with disruption of the urothelial barrier as well as direct ketamine toxicity (i.e., decreased expression of junction proteins) in KIUT of the bladder. Chronic and high-frequency ketamine use is also associated with bladder inflammation mediated via neurogenic and IgE inflammation. Other non-mutually exclusive causes are nerve hyperplasia, hypersensitivity, cell apoptosis, microvascular damage, and overexpression of carcinogenic genes. Notwithstanding the evidence of KIUT in ketamine abusers, there is no evidence that ketamine and/or esketamine treatment in adults with mood disorders is associated with KIUT. However, all patients receiving ketamine/esketamine for mood disorder treatment should be queried about genitourinary symptoms during acute and, where applicable, maintenance dosing.