In vitro and in vivo interaction of oral contraceptive high dose (HD) with urine morphine diagnostic test

Introduction: Urine morphine test, in several countries is the most primarily available qualitative test for detecting opioid abusers. Since the users of illicit drugs attempt to defeat urine tests and there are also plenty of claims that usage of HD (high dose) contraceptive pills can result in false-negative results, we decided to design the present study to investigate the probable in vitro and in vivo interaction of HD contraceptives and urine morphine diagnostic test. Methods: Several high and low concentrations of ethinylestradiol (EE), levonorgestrel (LN), and both of them were made in the blank urine and urine samples obtained from morphine abusers and then were detected by Acon® urine test strips. Also, high and low doses of EE, LN, and both of them were administered orally to separate groups of control, morphine dependent, and morphine treated (20 mg/kg in single dose, s.c.) male Wistar rats (225 ± 25 g). The urine samples were collected during 3-6, 12-15, 21-24 h time intervals in metabolic cages and were examined by Acon® urine tests. Results: Neither contraceptive constituents nor their urine metabolites at different levels were able to negate the results of urine kits. Conclusion: We conclude that there is no interaction between HD contraceptives and urine morphine diagnostic tests both in vitro and in vivo. It is recommended to inform the results of this study to withhold further misusage of contraceptives and their possible adverse effects.