# Cannabis and Cocaine Use During Treatment: What Urine Testing Found > **Author:** Benjamin Caplan, MD (ABFM Board Certified, MA Lic. #240562, NPI: 1962722637) > **Publisher:** CED Clinic (https://cedclinic.com) > **Canonical URL:** https://cedclinic.com/cannabis-cocaine-use-treatment-urine-analysis/ > **Published:** 2026-08-11T09:53:36-04:00 | **Last Modified / Clinically Audited:** 2026-09-27T22:00:57-04:00 > **Clinical Summary:** cannabis and cocaine use during treatment: A secondary analysis of 301 participants in a medication trial found that THC-positive urine tests were associated... --- CED Clinical Relevance #84 [Cannabis Science](https://cedclinic.com/biphasic-effects-of-cannabis/) Evidence Report A peer-reviewed secondary analysis used 25 repeated urine-testing time points from 301 trial participants. It addresses a clinically important polysubstance-use question, but the association cannot show that cannabis caused cocaine use or that cannabis cessation would improve treatment outcomes. Clinical Insight | CED Clinic Relationships between cannabis and cocaine use in a randomized trial of combined buprenorphine and naltrexone for DSM-IV cocaine dependence. is a recent peer-reviewed paper that deserves more than a headline because it sits directly inside a common clinical question: the association between THC-positive and cocaine-positive urine tests during cocaine use disorder treatment. The useful reading is deliberately balanced. The paper gives CED readers a stronger evidence signal than a news blurb or anecdote, but it also shows why [cannabinoid medicine](https://cedclinic.com/cannabinoids-prostate-cancer-anti-tumor-drugs/) still needs product-specific, dose-specific, and patient-specific interpretation. For patients and clinicians, the point is not to convert the finding into a simple recommendation. The point is to understand what the study investigated, what it appeared to find, and where the evidence still stops short of a treatment rule. CannabisCocainePolysubstance UseTreatmentUrine Testing Audience Patients, caregivers, clinicians, and cannabis-science readers interested in cocaine use disorder treatment in people with co-occurring opioid abuse or dependence Primary Topic the association between THC-positive and cocaine-positive urine tests during cocaine use disorder treatment Source [Read the full source](https://pubmed.ncbi.nlm.nih.gov/42561565/) A secondary analysis of 301 participants in a medication trial found that THC-positive urine tests were associated with higher odds of cocaine-positive tests during eight weeks of treatment. The result supports careful assessment of polysubstance use, but it does not prove that cannabis caused cocaine use or that stopping cannabis would improve cocaine outcomes. What This Study Teaches Us The analysis found that THC-positive urine samples tended to occur alongside higher odds of cocaine-positive samples across repeated testing. Because cannabis exposure was not randomized, the finding is an association within a selected treatment population, not a test of cannabis cessation or a causal effect of THC. Why This Matters Cannabis and stimulant use often coexist, yet counseling can become more certain than the evidence. This paper adds repeated biological measurements during treatment and helps clinicians ask a practical question: when cannabis and cocaine use travel together, how should both patterns be assessed without assuming that one caused the other? Study Snapshot Study Type Secondary observational analysis of a previously reported double-blind randomized medication trial Population 301 adults meeting criteria for opioid abuse or dependence during cocaine use disorder treatment Participant Profile Mean age 46 years; 78.4% male, 89.7% non-Hispanic, and 66.5% African American Parent Trial CTN0048, with extended-release naltrexone plus placebo, 4 mg/day, or 16 mg/day buprenorphine Observation Period Eight weeks with 25 urine-testing time points Exposure THC-positive urine drug screen Outcome Cocaine-positive urine drug screen Main Association OR 1.47; 95% CI 1.21 to 1.79 Interpretive Boundary Cannabis exposure was not randomized and the analysis did not test cannabis cessation Journal Addictive Behaviors Published July 29, 2026 PMID / DOI 42561565 / 10.1016/j.addbeh.2026.108817 Conflict Statement The authors reported no known competing financial interests or personal relationships Major Limitation Secondary analysis of an older trial in a selected, predominantly male population with co-occurring opioid problems Clinical Bottom Line THC-positive urine tests were associated with higher odds of cocaine-positive tests during treatment. The finding supports screening and discussion of both substances, but it does not establish direction, causation, or benefit from cannabis cessation. What the Analysis Tested Investigators reanalyzed repeated urine samples from 301 participants in CTN0048, a medication trial involving extended-release naltrexone and three buprenorphine conditions. The new question was observational: whether a THC-positive urine test was associated with the odds of a cocaine-positive urine test across 25 time points during eight weeks of treatment. The Main Finding THC-positive samples were associated with 47% higher odds of a cocaine-positive sample, with an odds ratio of 1.47 and a 95% confidence interval from 1.21 to 1.79. Repeated biological testing is a strength because it does not rely only on recall. Still, co-occurrence does not identify which behavior came first or why the two patterns clustered. Why Causation Remains Unresolved Participants were not randomly assigned to use or avoid cannabis. Shared severity, environment, treatment engagement, psychiatric symptoms, social factors, or other unmeasured differences could contribute to both urine-test results. The study therefore cannot show that THC exposure caused cocaine use, that cocaine use caused [cannabis use](https://cedclinic.com/cannabis-cardiovascular-health-insights-2024/), or that reducing cannabis would reduce cocaine use. How the Finding May Inform Care A THC-positive result can reasonably prompt a nonjudgmental discussion of frequency, motives, impairment, withdrawal, product potency, and how [cannabis use](https://cedclinic.com/cannabis-cardiovascular-health-insights-2024/) fits within the patient’s broader treatment goals. Counseling should remain individualized. The paper supports assessing both substances, not presenting cannabis cessation as a proven cocaine-use intervention. Who the Result May Not Represent The cohort was selected for a trial involving cocaine dependence and co-occurring opioid abuse or dependence. Most participants were male, non-Hispanic, and African American, and the parent trial used DSM-IV criteria. Results may not generalize to people using cannabis without cocaine, to current treatment settings, or to populations with different demographic and clinical characteristics. How Strong Is This Evidence? The analysis included 301 participants, repeated objective urine measures across 25 time points, and a peer-reviewed statistical model. These features make the association more informative than a single cross-sectional self-report. Where This Paper Deserves Skepticism This was not a randomized test of cannabis exposure or cessation. The secondary analysis used a selected parent-trial population, cannot establish temporal direction, and may retain confounding by illness severity, treatment engagement, environment, or other substance use. What This Paper Does Not Show The paper does not show that cannabis causes cocaine use, that THC-positive urine reflects dose or impairment, that stopping cannabis improves cocaine outcomes, or that the result applies to all patients using either substance. How This Fits With the Broader Clinical Conversation Polysubstance use is often better understood as a pattern shaped by availability, reinforcement, coping, psychiatric symptoms, and social context than as a simple one-drug-causes-another sequence. The clinical value of this analysis is its reminder to assess [cannabis use](https://cedclinic.com/cannabis-cardiovascular-health-insights-2024/) within the full substance-use picture while preserving uncertainty about cause and treatment effect. Dr. Caplan’s Take *The association is clinically relevant, but it should not be converted into a causal warning. A urine-test pattern can identify a conversation that needs to happen without deciding the answer in advance.* *For treatment planning, I would use this result to ask better questions about both substances, define the patient’s goals, and measure change over time. I would not promise that changing cannabis use alone will change cocaine outcomes.* What a Careful Reader Should Take Away A careful reader should treat THC positivity as a marker associated with cocaine positivity in this specific treatment cohort, not as proof of causation or a validated cessation strategy. Evidence Interpretation Guide Table of Contents - [How to Interpret This The Association Between Thc-Positive And Cocaine-Positive Urine Tests During Cocaine Use Disorder Treatment Evidence Without Overstating It](#How_to_Interpret_This_The_Association_Between_Thc-Positive_And_Cocaine-Positive_Urine_Tests_During_Cocaine_Use_Disorder_Treatment_Evidence_Without_Overstating_It)[A Four-Step Reading Frame](#A_Four-Step_Reading_Frame) - [The Same Study Can Mean Different Things Depending on the Question Being Asked](#The_Same_Study_Can_Mean_Different_Things_Depending_on_the_Question_Being_Asked)[A Signal Worth Discussing, Not Self-Prescribing](#A_Signal_Worth_Discussing_Not_Self-Prescribing) - [Useful Evidence With Practical Gaps](#Useful_Evidence_With_Practical_Gaps) - [Small Evidence Bases Can Look Larger in Review Form](#Small_Evidence_Bases_Can_Look_Larger_in_Review_Form) - [Outcome Measures Do Not Answer Every Bedside Question](#Outcome_Measures_Do_Not_Answer_Every_Bedside_Question) - [A Step Forward, Not the Final Word](#A_Step_Forward_Not_the_Final_Word) - [Monitoring Matters](#Monitoring_Matters) - [What Better Evidence Would Need](#What_Better_Evidence_Would_Need) - [Access Should Not Outrun Evidence Quality](#Access_Should_Not_Outrun_Evidence_Quality) - [Frequently Asked Questions](#Frequently_Asked_Questions)[Related](#Related) ## How to Interpret This The Association Between Thc-Positive And Cocaine-Positive Urine Tests During Cocaine Use Disorder Treatment Evidence Without Overstating It A useful evidence report should let the signal breathe without inflating it. The right question is not whether the paper is positive or negative, but what kind of decision it can responsibly support. ### A Four-Step Reading Frame **Evidence type**Start by identifying whether the paper is a randomized trial, review, meta-analysis, observational study, or protocol. **Population**Ask whether the studied population matches the patient or clinical scenario involving cocaine use disorder treatment in people with co-occurring opioid abuse or dependence. **Outcome meaning**Look at what actually changed, how it was measured, and whether the change would matter in daily life. **Safety and uncertainty**Read limitations and adverse effects as part of the result, not as a footnote. The Research Question What does the current evidence suggest about the association between THC-positive and cocaine-positive urine tests during cocaine use disorder treatment? The Patient Question Does this mean I should use cannabinoids for cocaine use disorder treatment in people with co-occurring opioid abuse or dependence? The Bottom Line The evidence can inform a careful conversation, but it does not replace individualized clinical care. CED Perspective Lens ## The Same Study Can Mean Different Things Depending on the Question Being Asked Scientific papers rarely answer a single question. Patients, clinicians, researchers, policymakers, and critics often read the same data differently. The perspectives below explore how this study looks through several evidence-based lenses. Lens Overview This paper can be read through several lenses. The most useful readings keep the association between THC-positive and cocaine-positive urine tests during cocaine use disorder treatment clinically relevant without treating the evidence as more settled than it is. #### A Signal Worth Discussing, Not Self-Prescribing For patients interested in the association between THC-positive and cocaine-positive urine tests during cocaine use disorder treatment, the paper creates a reasonable conversation starter but not a do-it-yourself treatment plan. In this case, the key is to keep cocaine use disorder treatment in people with co-occurring opioid abuse or dependence in view while avoiding claims the study did not test. Lens takeaway Bring the evidence to a clinician; do not turn it into self-directed dosing. #### Useful Evidence With Practical Gaps Clinicians can use the paper to discuss cocaine use disorder treatment in people with co-occurring opioid abuse or dependence, but the evidence still leaves product, dose, monitoring, and patient-selection questions open. In this case, the key is to keep cocaine use disorder treatment in people with co-occurring opioid abuse or dependence in view while avoiding claims the study did not test. Lens takeaway The clinical value is in structured discussion, not automatic recommendation. #### Small Evidence Bases Can Look Larger in Review Form Systematic reviews can make a field feel mature even when the underlying trials remain few, short, or heterogeneous. In this case, the key is to keep cocaine use disorder treatment in people with co-occurring opioid abuse or dependence in view while avoiding claims the study did not test. Lens takeaway Review-level evidence still depends on the quality of the studies underneath it. #### Outcome Measures Do Not Answer Every Bedside Question The paper reports measurable outcomes, but patients also need information about durability, adverse effects, interactions, and real-world use. In this case, the key is to keep cocaine use disorder treatment in people with co-occurring opioid abuse or dependence in view while avoiding claims the study did not test. Lens takeaway Statistical improvement is not the same as a complete care plan. #### A Step Forward, Not the Final Word This paper advances the conversation by gathering available evidence, but it also highlights how much [cannabinoid research](https://cedclinic.com/cannabinoids-in-reward-processing-pain-perception/) still depends on small or uneven studies. In this case, the key is to keep cocaine use disorder treatment in people with co-occurring opioid abuse or dependence in view while avoiding claims the study did not test. Lens takeaway The field is moving, but the foundation is still being built. #### Monitoring Matters If cannabinoids are considered clinically, monitoring should include symptom response, side effects, sedation or impairment, medication interactions, and patient goals. In this case, the key is to keep cocaine use disorder treatment in people with co-occurring opioid abuse or dependence in view while avoiding claims the study did not test. Lens takeaway The practical layer determines whether a signal becomes useful care. #### What Better Evidence Would Need Stronger trials should define formulation, dose, comparator, duration, responder profiles, and safety monitoring before broad claims are made. In this case, the key is to keep cocaine use disorder treatment in people with co-occurring opioid abuse or dependence in view while avoiding claims the study did not test. Lens takeaway Better evidence needs specificity, not just bigger sample size. #### Access Should Not Outrun Evidence Quality Patients deserve access to careful information, but public messaging should not make early evidence sound settled. In this case, the key is to keep cocaine use disorder treatment in people with co-occurring opioid abuse or dependence in view while avoiding claims the study did not test. Lens takeaway Honest uncertainty protects both patients and the credibility of [cannabis medicine](https://cedclinic.com/essential-oils-industrial-hemp-antimicrobial-benefits/). Join the Conversation Have a question about how this applies to your situation? [Ask Dr. Caplan](https://benjamincaplan.com/ask-dr-caplan) Want to discuss this topic with other patients and caregivers? [Join the forum discussion](https://cedclinic.com/interact/discussion-forums/) [https://cedclinic.com/contact/](https://cedclinic.com/contact/) Physician-Led, Whole-Person Care A doctor who takes the time to truly understand you. Personal care that starts with listening and is guided by experience and ingenuity. Health, Longevity, Wellness One-on-One Cannabis Guidance Metabolic Balance [Leave a Message](https://cedclinic.com/contact/) [Metabolic Care](https://cedclinic.com/metabolic/metabolic-how-it-works/) [Medical Consulting](https://cedclinic.com/book/) [Cannabis Care](https://cedclinic.com/book/) [https://cedclinic.com/contact/](https://cedclinic.com/contact/) Share this Evidence Watch [X](https://twitter.com/intent/tweet?text=Cannabis+and+Cocaine+Use+During+Treatment%3A+What+Urine+Testing+Found&url=https%3A%2F%2Fcedclinic.com%2Fcannabis-cocaine-use-treatment-urine-analysis%2F) [LinkedIn](https://www.linkedin.com/sharing/share-offsite/?url=https%3A%2F%2Fcedclinic.com%2Fcannabis-cocaine-use-treatment-urine-analysis%2F) [BlueSky](https://bsky.app/intent/compose?text=Cannabis+and+Cocaine+Use+During+Treatment%3A+What+Urine+Testing+Found%20https%3A%2F%2Fcedclinic.com%2Fcannabis-cocaine-use-treatment-urine-analysis%2F) [Instagram](https://www.instagram.com/drcaplan/) [Substack](https://doctorapprovedcannabis.substack.com/) [RSS](https://cedclinic.com/feed/) Source: [Relationships between cannabis and cocaine use in a randomized trial of combined buprenorphine and naltrexone for DSM-IV cocaine dependence.](https://pubmed.ncbi.nlm.nih.gov/42561565/) Related Reading at CED Clinic Continue exploring the evidence [GLP-1 Medications and Substance Use Disorders](https://cedclinic.com/glp-1-cannabis-use-disorder-bmj-cohort-study/) Related CED context on observational addiction-treatment signals and why association should not be treated as proof of treatment effect. [Read the addiction evidence context](https://cedclinic.com/glp-1-cannabis-use-disorder-bmj-cohort-study/) [Repurposing Semaglutide for Cocaine Use Disorder](https://cedclinic.com/glp-1-cannabis-use-disorder-bmj-cohort-study/) A related cocaine-use-disorder protocol that helps distinguish a planned treatment test from the current secondary association analysis. [Review the treatment protocol](https://cedclinic.com/glp-1-cannabis-use-disorder-bmj-cohort-study/) [Cannabinoids, Cocaine, and Trauma Outcomes](https://cedclinic.com/cannabinoids-cocaine-trauma-mortality-outcomes-study/) Different clinical context involving cannabinoid and cocaine positivity, useful for seeing why population and outcome definitions matter. [Compare the trauma study](https://cedclinic.com/cannabinoids-cocaine-trauma-mortality-outcomes-study/) ## Frequently Asked Questions Does this study prove that the association between THC-positive and cocaine-positive urine tests during cocaine use disorder treatment works? No. It supports a clinically interesting signal, but proof requires larger, better-controlled, and more specific trials. Is this enough evidence to change treatment on its own? No. It can inform a clinical conversation, but it should not replace individualized medical judgment or established care. Why does study design matter here? Design affects how confidently readers can separate a true treatment effect from bias, placebo response, measurement choices, and patient selection. What is the biggest limitation? The biggest limitation is that the available studies are relatively small, heterogeneous, and not long enough to answer every practical safety question. Does this apply to every cannabis or CBD product? No. Products differ by cannabinoid content, dose, route, purity, and testing standards, so one paper cannot validate every product. What should patients ask their clinician? Patients should ask how the evidence relates to their own cocaine use disorder treatment in people with co-occurring opioid abuse or dependence, medication list, risks, goals, and monitoring plan. Are side effects still important if the findings are positive? Yes. Benefit and risk have to be interpreted together, especially for sedation, impairment, interactions, and vulnerable populations. Why include this as a full CED report? The paper is recent, clinically relevant, and evidence-based enough to deserve careful standalone interpretation rather than a short mention. What would stronger research add? Stronger research would clarify formulation, dose, duration, responder profiles, active comparators, long-term outcomes, and safety monitoring. What is the practical takeaway? The practical takeaway is cautious interest: the signal is worth knowing, but the clinical decision still has to be individualized. ### Related --- ### Verification & Medical Governance - **Lead Clinical Author:** Benjamin Caplan, MD - **Credentials:** Board Certified in Family Medicine (ABFM), Former CMO Canna Care Docs (250,000+ patients supervised), Founder & CMO CED Clinic & CED Foundation, Author of *The Doctor-Approved Cannabis Handbook* (Penguin Random House). - **Clinical Scale:** 350,000+ lifetime evaluations overseen; 81,008-patient Real-World Evidence Registry (`~/.ced_rwe_vault.db`); 125,000+ peer-reviewed study literature observatory (`http://localhost:8768/api/explorer/terminal`). - **License Verification:** Commonwealth of Massachusetts License #240562 (https://checkahealthlicense.mass.gov/). - **NPI Registry:** 1962722637 (https://npiregistry.cms.hhs.gov/provider-view/1962722637). - **Ethics & Data Privacy:** Clinical registry observations adhere strictly to HIPAA Safe Harbor de-identification (45 CFR § 164.514(b)) and criteria for secondary research exemption under 45 CFR § 46.104(d)(4).