One‐stop clinic for ketamine‐associated uropathy: report on service delivery model, patients' characteristics and non‐invasive investigations at baseline by a cross‐sectional study in a prospective cohort of 318 teenagers and young adults

Abstract

ObjectiveTo describe a service delivery model and report the baseline characteristics of patients investigated by a non-invasive approach for ketamine-associated uropathy. Patients and MethodsThis was a cross-sectional study in a prospective cohort of patients who attended their first visit and underwent non-invasive investigations at a dedicated centre to treat ketamine-associated uropathy in Hong Kong from December 2011 to July 2013. Data on demographics, illicit ketamine use, symptoms scores and voiding function parameters at baseline were prospectively collected. Differences between active abusers and ex-abusers, and risk factors for the most symptomatic group were investigated by univariate and multivariate analysis. ResultsIn all, 318 patients completed the non-invasive assessment at their first visit and were eligible for inclusion. In all, 174 were female and the mean (SD) age of the entire cohort was 24.4 (3.1) years. Patients had used ketamine for a mean (SD) period of 81 (36) months. The mean (SD) ketamine use per week was 18.5 (15.8) g. In all, 214 patients were active abusers while 104 were ex-abusers but had persistent lower urinary tract symptoms. The mean (SD) voided volume, bladder capacity, and bladder emptying efficiency were 111.5 (110) mL, 152.5 (126) mL and 73.3 (26.9)%, respectively. The ex-abusers had a lower symptom score (19.3 vs 24.1; P < 0.001), a larger voided volume (126 vs 85 mL; P < 0.001), and a larger bladder capacity (204.8 vs 126.7 mL; P < 0.001) compared with active abusers. Multivariate analysis found female gender was associated with a higher symptom score (odds ratio [OR] 2.39; 95% confidence interval [CI] 1.35-4.23; P = 0.003) and a smaller voided volume (OR 1.9; 95% CI 1.1-3.3; P = 0.02). Ketamine taken (g/week) was another risk factor for a higher symptom score (OR 1.03; 95% CI 1.01-1.05; P = 0.002). Status of ex-abuser was the only protective factor associated with fewer symptoms, larger voided volume and bladder capacity. ConclusionsAn effective service model for recruiting patients with ketamine-associated uropathy is possible. With such a service model as a platform, further prospective studies are warranted to investigate the appropriate choice of treatment for this new clinical entity.

Population-based survey of the prevalence of lower urinary tract symptoms in adolescents with and without psychotropic substance abuse

“…This observation is in agreement with our previous findings and our postulation that females appear to be more susceptible to the chemically induced injury following illicit use of ketamine for unknown reasons. 25 Non-ketamine substance users also experienced more LUTSs than the control subjects in this study although the prevalence was not as high as that of ketamine users. Most recently Korean investigators have reported a 77% prevalence rate of LUTS among a group of young methamphetamine (also known as 'ice') users, and suggested that a pathological dopaminergic mechanism plays a predominant role in methamphetamine-associated LUTS.…”

“…We have recently reported that both the dose and frequency of ketamine use and female gender are associated with the severity of the LUTS at presentation among the young patients who sought urological treatment for ketamine-associated uropathy. 25 In the present study, female ketamine users were at a higher risk of developing LUTS than males. This observation is in agreement with our previous findings and our postulation that females appear to be more susceptible to the chemically induced injury following illicit use of ketamine for unknown reasons.…”

“…13 This chemically induced cystitis as a result of the urinary metabolites of ketamine is associated with severe LUTS with the possible consequence of irreversible bladder damage. 12,25 Little information is available in the medical literature about the prevalence of LUTS among ketamine users. An online survey conducted in the UK reported a prevalence of 26.6% of at least one LUTS in the last 12 months among 1285 participants who had illicitly used ketamine.…”

Risks Associated with Misuse of Ketamine as a Rapid-Acting Antidepressant

“…Future treatment strategies need to be developed to decrease the risk of adverse events associated with long-term ketamine treatment for depression. Impairment of learning and memory [36] 50 and 100 ng/mL Impairment of episodic memory and recognition memory [37] 0.23 and 0.5 mg/kg Impairment of executive function [45] 0.54 mg/kg Mild increases in blood pressure [52] 0.23 mg/kg Adverse events related to mental status [47] 0.5 mg/kg Psychotomimetic effects [40,78] 0.3 and 0.5 mg/kg Cardiovascular side-effects [8,49] 18.5 g/week Uropathy [56] …”

“…The symptoms associated with the uropathic effects were mainly severe urgency, urinary frequency, intermittent hematuria, nocturia, dysuria, and bladder pain [56][57][58][59]. The duration and dosage of ketamine were proposed to be related to an increase in urinary tract dysfunction [58,60].…”