What urologists need to know about ketamine-induced uropathy: A systematic review

British Association of Urological Surgeons Consensus statements on the management of ketamine uropathy

OBJECTIVES

To provide guidance in the form of consensus statement in the management of ketamine uropathy.

METHODS

A literature review of ketamine uropathy was performed. The consensus method was of a modified nominal group technique and has been use in the previous British Association of Urological Surgeons (BAUS) consensus documents and was led by the Female, Neurological and Urodynamic Urology Section of the BAUS.

RESULTS

A number of consensus statements detailing the assessment and management of urological complications relate to the recreational use of ketamine (ketamine uropathy) in both elective and emergency urology settings.

CONCLUSION

Comprehensive management pathway for ketamine-related urinary tract dysfunction and uropathy has been detailed.

Hourglass Bladder Deformity Induced by Chronic Ketamine Abuse

Regular and chronic use of ketamine causes inflammatory changes in the urinary tract. Imaging has a crucial role in the assessment of this pathology. A particular imaging characteristic of an hourglass-shaped bladder is highlighted in three cases of ketamine intoxication. Teaching point: Three cases of ketamine intoxication with a characteristic bladder deformation are reported.

Newer therapies and surgical management of ketamine-induced uropathy: A review

BACKGROUND AND AIMS

Ketamine use as a recreational drug is becoming more popular nowadays. Ketamine-induced uropathy (KIU) is a late finding observed with long-term use of ketamine. A systematic review of Ketamine-Induced Uropathy was performed to emphasise its key clinical manifestations, mechanism of action and establish an effective treatment pathway.

METHODS AND RESULTS

A literature search was conducted in MEDLINE via Pubmed and Cochrane using the keywords ketamine and bladder, ketamine and uropathy, and ketamine and epidemiology. The search strategy was limited to articles published from 2000 to 2023. Both animal and human studies were included. A total of 101 papers were reviewed based on topic relevance from the title and abstracts available. While ketamine is a controlled drug in the United Kingdom (UK) and other countries, 283 ketamine-related deaths have been reported in the UK. There is no definite pathogenesis but multiple potential mechanisms that cause KIU and its related symptoms. KIU involves chronic inflammation of the bladder, ureteral wall thickening, hydronephrosis and finally, chronic renal failure. A multidisciplinary approach is paramount when managing these patients to break the vicious cycle. The mainstay of medical and surgical treatment pathways is continued abstinence to prevent symptom relapse. This review included the pathophysiology, novel medical treatments and surgical management of KIU.

CONCLUSION

KIU is a rare but significantly disabling condition often seen among ketamine abusers. With the rising trend in drug addiction, KIU is expected to be more common. Unfortunately, it is a late complication in chronic ketamine abusers and is only partially reversible even with abstinence. This review discusses this rare entity's newer medical treatments and surgical options.

Ketamine's acute effects on negative brain states are mediated through distinct altered states of consciousness in humans

Ketamine commonly and rapidly induces dissociative and other altered states of consciousness (ASCs) in humans. However, the neural mechanisms that contribute to these experiences remain unknown. We used functional neuroimaging to engage key regions of the brain's affective circuits during acute ketamine-induced ASCs within a randomized, multi-modal, placebo-controlled design examining placebo, 0.05 mg/kg ketamine, and 0.5 mg/kg ketamine in nonclinical adult participants (NCT03475277). Licensed clinicians monitored infusions for safety. Linear mixed effects models, analysis of variance, t-tests, and mediation models were used for statistical analyses. Our design enabled us to test our pre-specified primary and secondary endpoints, which were met: effects of ketamine across dose conditions on (1) emotional task-evoked brain activity, and (2) sub-components of dissociation and other ASCs. With this design, we also could disentangle which ketamine-induced affective brain states are dependent upon specific aspects of ASCs. Differently valenced ketamine-induced ASCs mediated opposing effects on right anterior insula activity. Participants experiencing relatively higher depersonalization induced by 0.5 mg/kg of ketamine showed relief from negative brain states (reduced task-evoked right anterior insula activity, 0.39 SD). In contrast, participants experiencing dissociative amnesia showed an exacerbation of insula activity (0.32 SD). These results in nonclinical participants may shed light on the mechanisms by which specific dissociative states predict response to ketamine in depressed individuals.

Ketamine-induced uropathy: A narrative systemic review of surgical outcomes of reconstructive surgery

Aims

Refractory ketamine-induced uropathy (KU) (RKU) has devastating effects on the lower urinary tract leading to ureteral obstruction and even renal failure. The only effective treatment for RKU is major surgical reconstruction or urinary diversion. Nevertheless, there is a paucity of awareness about this destructive condition; the aim of this study is to conduct a narrative systemic review of all surgical outcomes of RKU.

Methods

This is an English language literature review of surgical outcomes in KU patients who underwent reconstructive lower urinary tract surgery or urinary diversion through 5 August 2022. Two independent researchers assessed the relevance of each paper and disputes were settled by a third party. In-vitro, animal studies, letters to the editor and papers that did not evaluate surgical outcomes were excluded.

Results

Of the 50 763 identified articles, 622 were relevant based on title, 150 based on abstract, but only 23 papers were relevant by content. In all, 875 patients were documented as having KU, of whom 193 (22%) underwent reconstructive surgery. The data were disconcerting, as the apparent rapid progression from the beginning of KU to end-stage bladder was only a 1-year difference of ketamine abuse between those patients who required surgery (4.4 years) and those that did not (3.4 years).

Conclusions

The data suggest that the time interval from the beginning of ketamine-induced uropathy to the end-stage bladder may be measured in months, confounding decision making. There is a dearth of literature about KU, and more research is needed to better understand this pathology.

Efficacy and adverse effects of ketamine versus electroconvulsive therapy for major depressive disorder: A systematic review and meta-analysis

BACKGROUND

ECT is considered the fastest and most effective treatment for TRD. Ketamine seems to be an attractive alternative due to its rapid-onset antidepressant effects and impact on suicidal thoughts. This study aimed to compare efficacy and tolerability of ECT and ketamine for different depression outcomes (PROSPERO/CRD42022349220).

METHODS

We searched MEDLINE, Web of Science, Embase, PsycINFO, Google Scholar, Cochrane Library and trial registries, which were the ClinicalTrials.gov and the World Health Organization's International Clinical Trials Registry Platform, without restrictions on publication date.

SELECTION CRITERIA

randomized controlled trials or cohorts comparing ketamine versus ECT in patients with TRD.

RESULTS

Eight studies met the inclusion criteria (of 2875 retrieved). Random-effects models comparing ketamine and ECT regarding the following outcomes were conducted: a) reduction of depressive symptoms severity through scales, g = -0.12, p = 0.68; b) response to therapy, RR = 0.89, p = 0.51; c) reported side-effects: dissociative symptoms, RR = 5.41, p = 0.06; nausea, RR = 0.73, p = 0.47; muscle pain, RR = 0.25, p = 0.02; and headache, RR = 0.39, p = 0.08. Influential & subgroup analyses were performed.

LIMITATIONS

Methodological issues with high risk of bias in some of the source material, reduced number of eligible studies with high in-between heterogeneity and small sample sizes.

CONCLUSION

Our study showed no evidence to support the superiority of ketamine over ECT for severity of depressive symptoms and response to therapy. Regarding side effects, there was a statistically significant decreased risk of muscle pain in patients treated with ketamine compared to ECT.

Ketamine-Induced Cystitis: A Comprehensive Review of the Urologic Effects of This Psychoactive Drug

Ketamine is a common medical anesthetic and analgesic but is becoming more widely used as a recreational drug. Significant side effects on the urinary tract are associated with frequent recreational ketamine use most notably ketamine-induced cystitis (KIC). Regular ketamine consumption has been shown to increase the risk of cystitis symptoms by 3- to 4-fold, and cessation of ketamine use is usually associated with improvement of symptoms. Common KIC-related problems are urinary pain and discomfort, bladder epithelial barrier damage, reduced bladder storage and increased pressure, ureter stenosis, and kidney failure, all of which significantly impact patients' quality of life. Furthermore, it becomes a vicious cycle when KIC patients attempt to manage their urinary pain with increased ketamine use. The precise pathophysiology of KIC is still unknown but several theories exist, most of which highlight the inflammatory signaling pathways leading to bladder epithelium damage due to presence of ketamine in the urine. Empirical treatment options for KIC are available and consist of ketamine cessation, noninvasive therapies, and surgery, and should be decided upon based on the time course and severity of the disease. Of note, cessation of use is strongly recommended for all KIC patients, and should be supplemented with motivational interviews and psychological and social support. It is crucial for clinicians to be familiar with KIC diagnosis and treatment, and to be prepared to have informed discussions with ketamine-using patients about the potential health consequences of ketamine.

Molecular Pathophysiology and Potential Therapeutic Strategies of Ketamine-Related Cystitis

Ketamine was first synthesized as a clinical medicine for anesthesia in 1970. It has been used as a recreational drug because of its low cost and hallucination effect in the past decade. Part of ketamine abusers may experience ketamine-related cystitis (KC) and suffer from lower urinary tract symptoms, including urinary frequency, urgency, and severe bladder pain. As the disease progression, a contracted bladder, petechial hemorrhage of the bladder mucosa, and ureteral stricture with hydronephrosis may occur. The pathophysiology of KC is still uncertain, although several hypotheses have been raised. Cessation of ketamine abuse is critical for the management of KC to prevent progressive disease, and effective treatment has not been established. Research has provided some theoretical bases for developing in vitro experiments, animal models, and clinical trials. This review summarized evidence of molecular mechanisms of KC and potential treatment strategies for KC. Further basic and clinical studies will help us better understand the mechanism and develop an effective treatment for KC.

Temporal Trends and Variability in Ketamine Use for Mechanically Ventilated Adults in the United States

Rationale The epidemiology of continuous ketamine use in the management of critically ill adults receiving invasive mechanical ventilation (MV) in the U.S. is unknown. Objective To quantify the temporal trends and variation across U.S. hospitals in continuous ketamine use. Methods We performed a retrospective cohort study of adults (age ≥18) receiving MV who were discharged (alive or dead) from U.S. hospitals contributing data to the Premier Healthcare Database between January 2008 and September 2018. We used mixed effects multivariable logistic regression modeling (fixed effects: patient and hospital characteristics; random effect: discharge hospital) to evaluate the associations of discharge quarter and discharge hospital with continuous ketamine use (defined as a charge for intravenous ketamine on ≥2 consecutive calendar days). Results We identified 2,059,599 MV adults across 842 hospitals; of these, 7,927 (0.4%) received continuous ketamine. Ketamine use increased over time from 0.07% of all patients in quarter 1 2008 to 1.1% of all patients in quarter 3 2018. After adjustment, the odds of receiving continuous ketamine were consistently increased starting in quarter 4 2011 (odds ratio [95% confidence interval]: 1.83 [1.09-3.06] vs quarter 1 2008, p=0.023) with >10-fold increased odds starting in quarter 2 2017. Out of 842 hospitals, 486 (57.7%) used continuous ketamine on at least one cohort patient during the study period. Across these hospitals ever using ketamine, median use was 0.2% (IQR 0.08%-0.5%) with 5 hospitals using continuous ketamine in >5% of patients. The adjusted median odds ratio for discharge hospital was 3.72 (95% confidence interval: 3.37-4.13) which was higher than the odds ratio for any patient or hospital covariable other than discharge quarter. Conclusions In U.S. hospitals, use of continuous infusion ketamine increased markedly over time in critically ill patients receiving MV, with substantial variability between hospitals. Given the unique properties of ketamine as a sedative, further research is needed to assess its safety and utility in critically ill populations.

Ketamine-induced uropathy: A diagnostic pitfall in an increasing healthcare issue in youngsters

Ketamine induced uropathy (KIU) is a urological condition increasing in prevalence, with similar symptoms to UTI, OAB syndrome or interstitial cystitis/bladder pain syndrome. We present the case of an 18-year old male who established severe LUTS and acute kidney injury due to KIU, in a short time-span of 6 months. Since cessation of ketamine is the cornerstone of treating KIU, correct and early diagnosis is essential. Physicians should therefore consider KIU as a differential diagnosis in storage LUTS, especially in younger patients with therapy-resistant LUTS.

Review of Animal Models to Study Urinary Bladder Function

Simple Summary

The treatment of urinary bladder dysfunction requires the knowledge of bladder function, which involves physiology, pathology, and even psychology. Several animal models are available to study a variety of bladder disorders. These models include animals from rodents, such as mice and rats, to nonhuman primates, such as rabbits, felines, canines, pigs, and mini pigs. This review adapted animal models to study bladder function according to facility, priority, and disease.

Abstract

The urinary bladder (UB) serves as a storage and elimination organ for urine. UB dysfunction can cause multiple symptoms of failure to store urine or empty the bladder, e.g., incontinence, frequent urination, and urinary retention. Treatment of these symptoms requires knowledge on bladder function, which involves physiology, pathology, and even psychology. There is no ideal animal model for the study of UB function to understand and treat associated disorders, as the complexity in humans differs from that of other species. However, several animal models are available to study a variety of other bladder disorders. Such models include animals from rodents to nonhuman primates, such as mice, rats, rabbits, felines, canines, pigs, and mini pigs. For incontinence, vaginal distention might mimic birth trauma and can be measured based on leak point pressure. Using peripheral and central models, inflammation, bladder outlet obstruction, and genetic models facilitated the study of overactive bladder. However, the larger the animal model, the more difficult the study is, due to the associated animal ethics issues, laboratory facility, and budget. This review aims at facilitating adapted animal models to study bladder function according to facility, priority, and disease.

Supplementation of Probiotic Butyricicoccus pullicaecorum Mediates Anticancer Effect on Bladder Urothelial Cells by Regulating Butyrate-Responsive Molecular Signatures

In bladder cancer, urothelial carcinoma is the most common histologic subtype, accounting for more than 90% of cases. Pathogenic effects due to the dysbiosis of gut microbiota are localized not only in the colon, but also in regulating bladder cancer distally. Butyrate, a short-chain fatty acid produced by gut microbial metabolism, is mainly studied in colon diseases. Therefore, the resolution of the anti-cancer effects of butyrate-producing microbes on bladder urothelial cells and knowledge of the butyrate-responsive molecules must have clinical significance. Here, we demonstrate a correlation between urothelial cancer of the bladder and Butyricicoccus pullicaecorum. This butyrate-producing microbe or their metabolite, butyrate, mediated anti-cancer effects on bladder urothelial cells by regulating cell cycle, cell growth, apoptosis, and gene expression. For example, a tumor suppressor against urothelial cancer of the bladder, bladder cancer-associated protein, was induced in butyrate-treated HT1376 cells, a human urinary bladder cancer cell line. In conclusion, urothelial cancer of the bladder is a significant health problem. To improve the health of bladder urothelial cells, supplementation of B. pullicaecorum may be necessary and can further regulate butyrate-responsive molecular signatures.

Should Ketamine Not Be Banned? A Scoping Review

OBJECTIVES

Although the importance of ketamine in clinical practice and in resource-poor settings and disaster zones, several attempts were made to reschedule it because of the issues around its misuse. Resisting future moves to reschedule ketamine is important for its continuous availability where needed. This scoping review addresses the question of whether ketamine should or should not be banned and the state of preparedness of low resource settings if ketamine petitions become successful in the future.

METHODS

A search was performed using PubMed and Google Scholar to identify articles published in the English language from March 2015 to August 2020. The articles were searched with a wide range of priori search terms related to the research questions. The selection of articles was based on relevance and eligibility.

RESULTS

Seventy-five articles were selected and grouped into 4 ethical themes. The search revealed that several articles addressed the importance of ketamine, pharmacology, misuse, supply, and consequences of a ketamine ban; however, none addressed how resource-poor countries should prepare for a future without the overreliance of ketamine.

CONCLUSION

Four ketamine petitions in about 10 years are an indication that another may resurface soon; therefore, it is important to continue to study the clinical importance of ketamine while discouraging its overreliance for clinical practice.

miR-98-5p plays a critical role in depression and antidepressant effect of ketamine

Ketamine has been demonstrated to be a rapid-onset and long-lasting antidepressant, but its underlying molecular mechanisms remain unclear. Recent studies have emerged microRNAs as important modulators for depression treatment. In this study, we report that miR-98-5p is downregulated in the prefrontal cortex and hippocampus of mice subjected to chronic social stress, while overexpressing it by its agonist alleviates depression-like behaviors. More importantly, we demonstrate that miR-98-5p is upregulated by ketamine administration, while inhibition of it by its antagonist blocks the antidepressant effect of ketamine. Our data implicate a novel molecular mechanism underlying the antidepressant effect of ketamine, and that therapeutic strategies targeting miR-98-5p could exert beneficial effects for depression treatment.

Ketamine enhances autophagy and endoplasmic reticulum stress in rats and SV-HUC-1 cells via activating IRE1-TRAF2-ASK1-JNK pathway

Background Ketamine-related cystitis (KC) has been researched in many clinical studies, but its exact mechanism is ambiguous and needs further research. Methods We established a KC rat model and analyzed physiological, biochemical, and urodynamic parameters of ketamine (KET)-related bladder injury. Bladder histologic feature, reactive oxygen species (ROS), autophagy-, apoptosis-, and endoplasmic reticulum stress (ERS)-related markers were examined by hematoxylin and eosin staining, Masson staining, ROS kit, quantitative real-time polymerase chain reaction, and western blot. In vitro, effects of 0.01, 0.1, and 1 mM KET on cell vitality, apoptosis, ROS level, autophagy-, apoptosis-, and ERS-related markers were examined again. Effects of KET-1 and salubrinal on complex formation, autophagy-, apoptosis-, and ERS-related markers were examined by Co-Immunoprecipitation and western blot. After transfection with shIRE1, complex formation, cell biological behaviors, ROS level, autophagy-, apoptosis-, and ERS-related markers were examined again. Results KET induced bladder hyperactivity and injury. KET facilitated urinary frequency, ROS production, and induced bladder histologic injury by activating autophagy-, apoptosis-, and ERS-related markers in rats. In vitro, KET (0.01, 0.1, and 1 mM) restrained cell vitality and elevated apoptosis and ROS level via activating autophagy-, apoptosis-, and ERS-related markers. Moreover, salubrinal reversed the promotion of KET-1 on complex formation, autophagy-, apoptosis-, and ERS-related marker expressions. After transfection with shIRE1, shIRE1 weakened complex formation induced by KET-1, and the effects of KET-1 on cells were offset by shIRE1. Conclusion KET enhanced autophagy and ERS in vivo and in vitro via restraining IRE1-TRAF2-ASK1-JNK pathway.

Rodent models of ketamine-induced cystitis

AIMS

Long-term or recreational use of ketamine affects the urinary system and can result in ketamine-induced cystitis (KIC). Rodent models of KIC are important to study KIC pathophysiology and are paramount to the future development of therapies for this painful condition. This review aims to provide a summary of rodent models of KIC, focusing on disease induction, experimental methods, and pathological features of the model.

METHOD

A literature search was performed using the National Center for Biotechnology Information (NCBI) Pubmed database up to March 2021. 20 articles met the inclusion criteria and were finally selected.

RESULTS

There are considerable variations in the rodent models used for studying KIC in terms of the strain of the animal being used; dose, duration, and route of ketamine administration to induce KIC, and assessment of pathological features.

CONCLUSION

KIC remains difficult to fully recapitulate in humans. Improved characterization of KIC models and the experimental parameters and meticulous discussion on translational limitations are required to improve the translational value of research using rodent models of KIC.

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.

Investigation of urinary components in rat model of ketamine-induced bladder fibrosis based on metabolomics

Background

Ketamine abuse has been linked to the system's damage, presenting with lower urinary tract symptoms (LUTS). While the pathogenesis of ketamine-induced urinary damage is not fully understood, fibrosis is believed to be a potential mechanism. A metabolomic investigation of the urinary metabolites in ketamine abuse was conducted to gain insights into its pathogenesis.

Methods

A rat model of ketamine induced bladder fibrosis was established through tail vein injection of ketamine hydrochloride and control group was established through tail vein injection of the equivalent normal saline. Hematoxylin and eosin (H&E) staining and Masson trichrome staining were performed to evaluated bladder pathology. Urinary components were detected based on a metabolomic approach using ultra-high performance liquid tandem chromatography quadrupole time of flight mass spectrometry (UHPLC-QTOFMS platform). Orthogonal projections analyzed the data to latent structures discriminant analysis (OPLS-DA) and bioinformatics analysis.

Results

The rat model of ketamine induced bladder fibrosis was confirmed through H&E and Masson trichrome staining. There were marked differences in the urinary metabolites between the experimental group and the control group. Compared to the control group, 16 kinds of differential metabolites were up-regulated and 102 differential metabolites were down-regulated in the urine samples of the ketamine group. Bioinformatics analysis revealed the related metabolic pathways.

Conclusions

Using a ketamine-induced bladder fibrosis rat model, this study identified the differential urinary metabolites expressed following ketamine treatment. These results provide vital clues for exploring the pathogenesis of ketamine-induced LUTS and may further contribute to the disease's diagnosis and treatment.

Is medicinal ketamine associated with urinary dysfunction issues? Assessment of both the European Medicines Agency (EMA) and the UK Yellow Card Scheme pharmacovigilance database-related reports

OBJECTIVE

A range of ketamine-induced uropathy (KIU) issues have been typically described in ketamine misusers. Conversely, more knowledge is needed in terms of medicinal ketamine-related urological disturbances, since ketamine prescribing is being increasingly considered for a range of medical and psychopathological conditions.

METHODS

To assess medicinal KIU issues, we aimed at analyzing both the 2005-2017 European Medicines Agency (EMA) and the 2006-2018 UK Yellow Card Scheme (YCS) pharmacovigilance databases.

RESULTS

A total number (eg, all categories) of 11 632 EMA ketamine-related adverse drug reaction (ADR) reports were here identified. Out of these, some 9971 ADRs (eg, 85.7% of the total) were judged as "suspect" and were here analyzed. Some 1758 ADRs (17.7% of 9971, corresponding to 194 individual patients) referred to urological issues, relating to either kidney/ureter (922 ADRs) or bladder/urethra (837 ADRs). Ketamine was the sole drug administered in 156/194 (80.4%) cases/patients. Although most cases occurred in the 1 month-1 year time frame following the start of ketamine prescribing, in 30 cases the ADR occurred within 48 hours. Most ADR-related cases resolved, although both sequelae (18 cases) and fatalities (79/1758; 4.5%) were recorded. Overall, YCS data were consistent with EMA findings, with some 50/217 (23%) ADRs referring to renal/urinary disorders.

CONCLUSIONS

Current data may only represent a gross underestimate of the KIU real prevalence issues. It is here suggested that chronic treatment involving higher doses/repeated exposure to ketamine be restricted to the context of controlled trials or clinical audits.