Objective: To assess the effect of a positive urine screen for cocaine on thyrotropin (TSH, also thyroid-stimulating hormone) concentrations.
Methods: In this retrospective cohort study, patients admitted to the mental health unit at an academic inpatient setting with a diagnosis of cocaine dependence or cocaine intoxication were routinely screened with urine drug toxicology tests and TSH concentrations. TSH concentrations from patients who tested positive for cocaine on urine toxicology were compared with patients having negative cocaine screenings.
Results: A total of 192 patients were included: 122 with a positive cocaine screen and 70 with a negative cocaine screen. All patients were screened using a highly sensitive TSH assay. A positive cocaine screen was not associated with a statistically significant difference in TSH concentrations compared with a negative cocaine screen. The percentage of patients with hypothyroidism (TSH >4.50 μIU/mL) or hyperthyroidism (TSH <0.40 μIU/mL) were similar in both study groups.
Conclusions: The study failed to show that a positive urine screen for cocaine was associated with a significant effect on serum TSH levels in patients admitted to a mental health unit with a diagnosis of cocaine dependence or cocaine intoxication. Our findings support those of a prior study that cocaine use does not affect routine thyroid function tests. The present study does not support the clinical practice of ordering a serum TSH screening test on patients admitted to inpatient psychiatry units soley because the urine screen is positive for cocaine.