Urinary symptoms and impaired quality of life in female ketamine users: persistence after cessation of use.

OBJECTIVE: To compare the urinary symptoms and quality of life in ex-ketamine abusers and controls. DESIGN: Prospective observational study. SETTING: A hospital in Hong Kong. PATIENTS: Female ex-ketamine abusers admitted to a local drug rehabilitation centre and age-matched controls attending a general gynaecology clinic between December 2009 and April 2010. MAIN OUTCOME MEASURES: Evaluation of urinary symptoms based on a 3-day bladder diary, and responses to the Urogenital Distress Inventory Short Form (UDI-6) and the Incontinence Impact Questionnaire Short Form (IIQ-7). The study group had repeat measurements 3 months later. RESULTS: Overall, 90% of ex-ketamine abusers had active urinary symptoms. On average, they had increased 24-hour urinary frequency (10.0 vs 5.8; P=0.001) and lower maximum voided volume (253.3 mL vs 401.9 mL; P<0.001) compared to controls. Correspondingly, the median functional bladder capacity was smaller (195.3 mL vs 261.2 mL; P=0.011) and the mean UDI-6 and IIQ-7 scores were higher (P<0.001). Among those who abused ketamine for 2 years or more, the mean UDI-6 and IIQ-7 scores were higher (P=0.03, P=0.02 respectively). When they stopped abusing ketamine for 3 months or more, their mean 24-hour urinary frequency had decreased (P=0.03), the maximum voided volume had increased (P=0.03) and the mean UDI-6 and IIQ-7 scores had decreased (P=0.04, P=0.02 respectively), although they were still higher than in controls. After 3 more months, in the ex-ketamine abusers there had been a further decrease in 24-hour urinary frequency (P=0.01) and a further improvement in quality of life based on mean UDI-6 scores (P=0.04) but nevertheless poorer than the control group (P<0.01). CONCLUSION: Female ex-ketamine abusers had significant urinary symptoms affecting their quality of life when studied at a mean of 8 (range, 0.5-48) months after cessation of use. The symptom severity was inversely correlated with the duration of cessation; though they improved with time, some still persisted.