Background: Methamphetamine cannot be detected through conventional urine screening tests or other analytical methods in methamphetamine abusers who have not used the drug for some time. In some instances, detection of methamphetamine in fingernails can be a good alternative. We aimed to determine the sensitivity and specificity of the one-step methamphetamine test strip used in the detection of methamphetamine in urine in the detection of methamphetamine in fingernails.
Methods: We took 72 fingernail samples, including 60 samples from methamphetamine abusers and 12 samples as controls from their relatives who had no history of methamphetamine use. The liquid-liquid extraction method was used on fingernail samples, and the resultant solution was tested with one-step methamphetamine test strip. We analysed participants' demographics including age, gender, duration of methamphetamine abuse and strip test results.
Results: The mean (SD) age of the participants was 25 (4.33) years. The mean (SD) duration of methamphetamine abuse was 10 (4.5) months. Of the 72 participants, 61 (84.7%) had positive and 11 (15.3%) had negative strip test results. All 60 methamphetamine abusers had positive test results. A positive or negative history of methamphetamine abuse was taken as the gold standard. The sensitivity and specificity of the test was 100% and 91.6%, respectively.
Conclusion: Performing liquid-liquid extraction on fingernails and using the strip test for detection of methamphetamine is a simple, inexpensive, rapid and accessible method, and its high sensitivity and specificity make it appropriate for screening. This method may be preferred over other urine and blood methamphetamine detection methods when the patient has not used the drug for a few days.