Ketamine is associated with lower urinary tract signs and symptoms.

BACKGROUND: Case reports and series indicate that ketamine, an anesthetic agent, causes lower urinary tract symptoms (LUTS). This study explored whether ketamine users were more likely to report LUTS compared to other substance users. METHODS: Participants were recruited through an online survey on erowid.org, a drug information website. A notice posted on the website invited substance users to participate in a web-based survey on "drug use and health". The notice did not mention ketamine, or other aspects of the research questions, to avoid participation bias. The anonymous survey collected demographics, drug use history, and history of LUTS (urinary frequency, urgency, incontinence, hematuria, and dysuria). RESULTS: Of 18,802 participants, 18.7% and 5.8% reported ever (lifetime) and recent (past-6-month) use of ketamine, respectively. Prevalence of LUTS among ever, recent, and never users of ketamine were 28%, 30%, and 24% respectively. Multivariate analysis showed significant associations between recent ketamine use and urinary symptoms. For each additional day of ketamine use in the last 180 days, the odds of developing urinary frequency, urgency, dysuria, and hematuria increased by 1.6%, 1.4%, 1.7%, and 1.9% respectively. One excess case of urinary frequency was reported per 17 recent users of ketamine. CONCLUSION: Compared to non-users, recent ketamine users had increased odds of LUTS. This is the first large-scale community-based study assessing the association of non-medical ketamine use with LUTS. Associations between ketamine and urological symptoms should be confirmed through longitudinal studies.

Abnormal visual experiences in individuals with histories of hallucinogen use: a Web-based questionnaire.

Despite longstanding reports of prolonged or reoccurring perceptual changes in a subset of hallucinogen users, very little is known about Hallucinogen Persisting Perception Disorder and related visual abnormalities in hallucinogen users. We used an online questionnaire to document the symptoms and relationship to drug use of unusual visual phenomena in hallucinogen users. 16,192 individuals viewed the information sheet and 2679 were included in the study. Of these, 224 reported having unrelated diagnoses associated with unusual visual experiences and were excluded from main analyses. Most (60.6%) of the remaining 2455 participants reported having experienced drug-free visual experiences that resembled hallucinogen effects. Probability of experiencing constant or near-constant symptoms was predicted by greater past exposure to specific hallucinogens, including lysergic acid diethylamide (LSD). Although symptoms were common, few (104, or 4.2% of the sample) found them distressing or impairing enough to consider seeking treatment. Visual changes in hallucinogen users may be more common than previously suspected and are worthy of further study.