Can Doxycycline cause a positive drug test?
By
Dr Natalia Marceli Stephanes (PhD)
Author bio
Dr Natália Marcéli Stephanes PhD is a Pharmacist with expertise in Drugs Administration and Toxicity; Discovery of New Drugs; Cancer Treatment; Biochemical Analyzes and Hematological Analyzes. She writes and reviews content on these topics.
Dr Natália Marcéli Stephanes’ Highlights:
- Pharmacist at the Department of Health of Santa Catarina State, Brazil
- PhD with a focus on oncology treatment
- Years of experience in commercial pharmacy
- Bachelor, Master and PhD degrees in Pharmacy at the Federal University of Santa Catarina
Professional Experience:
From her undergraduate studies to her Master’s and Doctorate degrees in Pharmacy, Dr Natália Marcéli Stephanes has participated in numerous scientific studies in the field of oncology and onco-hematology at the University Hospital of the Federal University of Santa Catarina, Brazil. Her research has focused on understanding the molecular and biochemical bases of malignant neoplasms and investigating safer and more effective therapeutic alternatives.
Dr Natália Marcéli Stephanes has also served as an assistant professor of haematology for undergraduate students at the Federal University of Santa Catarina. Additionally, she held the position of professor of Hospital Pharmacy at the Qualificar Technical School in Brazil, where she developed instructional materials for use in the Pharmacy Postgraduate Program at the Leonardo Da Vinci University Center.
In addition to her academic experiences, Dr Natália Marcéli Stephanes possesses a strong expertise in commercial pharmacy, with in-depth knowledge of medications, their routes of administration, desired effects, adverse effects, and toxicity.
Currently, Dr Natália Marcéli Stephanes works as a Pharmacist at the Health Department of Santa Catarina State, where her role entails providing pharmaceutical scientific consulting services to judges.
Education:
- 2016 Bachelor in Pharmacy at the Federal University of Santa Catarina, Brazil
- 2018 Master in Pharmacy at the Federal University of Santa Catarina, Brazil
- 2023 PhD in Pharmacy at the Federal University of Santa Catarina, Brazil
The main publications of Dr Natália Marcéli Stephanes are:
Falchetti M ; Delgobo M, Zancanaro H, Almeida K, Das Neves RN, Dos Santos B, Stefanes NM, et al. Bishop Omics-based identification of an NRF2-related auranofin resistance signature in cancer: Insights into drug repurposing. Comput. Biol. Med [Internet]. 2023; 152:106347.
Feuser PM, Matos dos Santos PC, Cordeiro AP, Stefanes NM, Walter LO, Maioral MF, Santos-Silva MC, et al. Antineoplastic activity of free 4-nitrochalcone and encapsulated in poly(thioether-ester) nanoparticles obtained by thiol-ene polymerization in two human leukemia cell lines (Jurkat and K562). J Drug Deliv Sci Technol [Internet]. 2022; 67:102924.
Jacques AV, Stefanes NM, Walter LO, Perondi DM, Efe FL, Souza LFS, Sens L, et al. Synthesis of chalcones derived from 1-naphthylacetophenone and evaluation of their cytotoxic and apoptotic effects in acute leukemia cell lines. Bioorg. Chem [Internet]. 2021; 116:105315.
Duarte BF, Vieira DSC, Lisboa ML, Stefanes NM, Grando LJ, Santos-Silva MC. Características clínico-epidemiológicas de pacientes portadores de carcinoma de células escamosas de boca. Arquivos Catarinenses de Medicina. 2021; 50(2): 232–245.
Machado V, Jacques AV, Stefanes NM, Santos-Silva MC, Biavatti MW. Anti-leukemic activity of semisynthetic derivatives of Lupeol. Nat. Prod. Res. 2021; 35(22):4494-4501.
Bigolin A, Maioral MF, Stefanes NM, Mascarello A, Chiaradia-Delatorre LD, Nunes RJ, Yunes RA, et al. A novel sulfonamide derivative as a strong and selective apoptotic agent against hematological malignancies. Chem. Pap. 2020; 74:2965–2976.
Bigolin A, Maioral MF, Stefanes NM, Zatelli GA, Philippus AC, Falkenberg MB, Santos-Silva MC. Cytotoxic mechanisms of primin, a natural quinone isolated from Eugenia hiemalis, on hematological cancer cell lines. Anticancer Drugs. 2020; 31(7):709-717.
Maioral MF, Stefanes NM, Neufeldt PD, Chiaradia-Delatorre LD, Nunes RJ, Santos-Silva MC. Aldehyde biphenyl chalcones induce immunogenic apoptotic-like cell death and are promising new safe compounds against a wide range of hematologic cancers. Future Med. Chem. 2020; 12(8):673–688.
Perondi DM, Jacques AV, Stefanes NM, Maioral MF, Sens L, Pacheco LA, Cury NM, et al. A novel thiosemicarbazone as a promising effective and selective compound for acute leukemia. Anticancer Drugs. 2019; 30(8):p 828-837.
Rengifo AFC, Stefanes NM, Toigo J, Mendes C, Argenta DF, Dotto MER, Santos-Silva MC, et al. PEO-chitosan nanofibers containing carboxymethyl-hexanoyl chitosan/dodecyl sulfate nanoparticles loaded with pyrazoline for skin cancer treatment. Eur. Polym. J. 2019; 119:335-343.
Rengifo AFC, Stefanes NM, Toigo J, Mendes C, Santos-Silva MC, Nunes RJ, Parize AL, et al. A new and efficient carboxymethyl-hexanoyl chitosan/dodecyl sulfate nanocarrier for a pyrazoline with antileukemic activity. Mater. Sci. Eng. C [Internet]. 2019; 105:110051.
Maioral MF, Stefanes NM, Bigolin A, Zatelli GA, Philippus AC, Falkenberg MB, Santos-Silva MC. Miconidine acetate, a new selective and cytotoxic compound with synergic potential, induces cell cycle arrest and apoptosis in leukemia cells. Invest. New Drugs. 2019; 37:912–922.
Srefanes NM, Toigo J, Maioral MF, Jacques AV, Chiaradia-Delatorre LD, Perondi DM, Ribeiro AAB, et al. Synthesis of novel pyrazoline derivatives and the evaluation of death mechanisms involved in their antileukemic activity. Bioorg. Med. Chem. 2019; 27(2):375-382.
Maioral MF, Bodack CN, Stefanes NM, Bigolin A, Mascarello A, Chiaradia-Delatorre LD, Yunes RA, et al. Cytotoxic effect of a novel naphthylchalcone against multiple cancer cells focusing on hematologic malignancies. Biochim. 2017; 140:48-57.
You can view some of Dr Natália’s work below and links to her professional profile below.
Research Gate: https://www.researchgate.net/profile/Natalia-Stephanes
Linkedin: https://www.linkedin.com/in/nataliamarceli/
Can Doxycycline cause a positive drug test?
Doxycycline may or may not cause a false positive drug test. Doxycycline is a prescription antibiotic which is used for the treatment of a number of bacterial infections.
Although it is not a controlled substance per se and doesn’t structurally resemble any drug of abuse either, it can still cause a false positive for Opiates (1).
This is because of the cross-reactivity of antibodies used in standard urine drug immunoassay and this is exactly why this method of drug testing is considered preliminary.
In case of a positive result, confirmatory tests may confirm the preliminary findings, which in most cases are not accurate.
How long does Doxycycline stay in your system?
Doxycycline has a half-life of about 15-22 hours, which is the time taken by this medication to reduce its initial peak concentration to half. The remaining concentration keeps reducing to half every 15-22 hours until the drug is completely washed out from your body.
The process can take a few days, typically 4-5. However, this time period is average for healthy adults. People with underlying health conditions, especially hepatic insufficiency, can experience delayed drug metabolism.
How to avoid Doxycycline showing up on a drug test?
There is no way to avoid Doxycycline showing up in your drug test if you’re currently taking it. The medication sometimes does not even get detected. However, a false positive on Doxycycline is always considered a possibility.
In such a case, it’s best to talk to your healthcare provider and keep your prescription with you to submit to the test conducting authorities prior to your drug test.
This would help them know that you are currently taking a medication that is capable of causing a false positive. These inaccurate findings are pretty common with urine drug Immunoassays.
More accurate testing procedures like Gas Chromatography – Mass spectroscopy are not associated with false positives (2). However, they are quite expensive and not everyone can afford them.
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References
1.-
Alyson Schwebach, Jennifer Ball. Urine Drug Screening: Minimizing False Positives and False Negatives to Optimize Patient Care. US Pharm. 2013;38(12):1-6. Available at: https://www.uspharmacist.com/article/urine-drug-screening-minimizing-false-positives-and-false-negatives-to-optimize-patient-care
2.-
Ramoo B, Funke M, Frazee C, Garg U. Comprehensive Urine Drug Screen by Gas Chromatography/Mass Spectrometry (GC/MS). Methods Mol Biol. 2016;1383:125-31. doi: 10.1007/978-1-4939-3252-8_15. PMID: 26660182. Available from: https://pubmed.ncbi.nlm.nih.gov/26660182/
