Focused Clinical Reference Series

Tox In Focus — one topic at a time.

Tox In Focus delivers 1–2 page reference guides on specific drugs, drug classes, testing technologies, and validity concepts — the resource you reach for when you need to get smart on something fast, or explain it to someone else.

37 Volumes Published
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1–2 pages. Clinically dense.

Every volume is a focused reference document — pharmacology, detection science, immunoassay gaps, clinical implications, and what the result actually means.

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One topic per volume

A single drug, drug class, testing technology, or validity concept — covered completely, without the surrounding noise.

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Available by request

Volumes are available to subscribers and by request. Contact Dr. Bundy to get access to existing volumes or request a topic.

Complete Library

Tox In Focus Series

Request a Volume →

Emerging Adulterants & Novel Threats

Vol. 04 May 2026 Xylazine  ·  Alpha-2 veterinary sedative ('Tranq'); not reversed by naloxone Request
Vol. 02 May 2026 Cychlorphine  ·  Benzimidazolone opioid not detected by standard IA; no POC strip Request
Vol. 03 May 2026 Carfentanil  ·  Ultra-potent fentanyl analogue; 10,000x morphine; IA unreliable Request
Vol. 08 Jul 2026 NPS Opioids  ·  Nitazenes and designer synthetic opioids outside the fentanyl panel Request
Vol. 30 Jul 2026 Fluoro-2oxo-PCE  ·  Novel dissociative; positional isomers; fentanyl co-exposure Request
Vol. 06 Jul 2026 Kratom  ·  Mitragynine and 7-OH; opioid-class alkaloids; LC-MS/MS only Request

Opioids

Vol. 07 Jul 2026 Fentanyl and Analogues  ·  Why a fentanyl-negative result does not rule out an analogue Request
Vol. 24 Jul 2026 Opioids  ·  Parent-metabolite relationships; poppy seed; synthetics missed by IA Request
Vol. 21 Jul 2026 Heroin  ·  6-MAM confirms heroin; poppy seed vs prescription opioids Request
Vol. 16 Jul 2026 Buprenorphine and Naloxone  ·  MAT monitoring; norbuprenorphine ratio and 'shaving' Request
Vol. 26 Jul 2026 Naltrexone  ·  Opioid antagonist; MAT adherence; Vivitrol depot timing Request
Vol. 37 Jul 2026 Levorphanol  ·  Methadone-like opioid; DXM/dextrorphan cross-reactivity Request

Stimulants

Vol. 15 Jul 2026 Methamphetamine  ·  d/l isomer interpretation; medicinal vs illicit sources Request
Vol. 19 Jul 2026 Cocaine  ·  Benzoylecgonine; highly specific IA; fentanyl co-exposure Request
Vol. 10 Jul 2026 Synthetic Cathinones  ·  'Bath salts' stimulants missed by amphetamine screens Request
Vol. 32 Jul 2026 Stimulants  ·  Prescription stimulant overview; analytes and how they screen Request
Vol. 31 Jul 2026 Methylphenidate  ·  Missed by amphetamine screens; ritalinic acid marker Request

Sedatives & Hypnotics

Vol. 12 Jul 2026 Benzodiazepines  ·  Immunoassay misses clonazepam and lorazepam; shared metabolites Request
Vol. 14 Jul 2026 NPS Benzodiazepines  ·  Designer benzos and 'benzo-dope' missed by benzo screens Request
Vol. 29 Jul 2026 Barbiturates  ·  Phenobarbital and butalbital; lethal withdrawal; enzyme inducer Request
Vol. 33 Jul 2026 Zolpidem  ·  Z-drug hypnotic not detected on benzodiazepine panels Request

Cannabinoids

Vol. 20 Jul 2026 THC / Cannabis  ·  cTHC; new use vs residual; delta-8; 2026 rescheduling Request
Vol. 13 Jul 2026 Synthetic Cannabinoids  ·  K2/Spice full agonists not detected on THC screens Request

Dissociatives

Vol. 25 Jul 2026 Ketamine  ·  NMDA antagonist; norketamine; therapy vs illicit Request
Vol. 28 Jul 2026 Dextromethorphan  ·  'Poor Man's PCP'; PCP false positive; NMDA antagonist Request

Psychiatric & Other Medications

Vol. 23 Jul 2026 Antidepressants  ·  SSRIs/SNRIs; bupropion and venlafaxine false positives Request
Vol. 27 Jul 2026 Antipsychotics  ·  Quetiapine to methadone FP; risperidone/paliperidone link Request
Vol. 36 Jul 2026 Bupropion  ·  Amphetamine false positive; hydroxybupropion marker Request
Vol. 09 Jul 2026 Gabapentinoids  ·  Gabapentin and pregabalin; misuse, diversion, very high levels Request
Vol. 35 Jul 2026 Acetaminophen  ·  Combination-product adherence; hepatotoxicity risk Request

Alcohol & Nicotine

Vol. 18 Jul 2026 Alcohol (EtG/EtS)  ·  EtG and EtS abstinence monitoring; incidental-exposure traps Request
Vol. 34 Jul 2026 Cotinine  ·  Nicotine biomarker; replacement and vaping test positive Request

Testing & Validity Concepts

Vol. 17 Jul 2026 Drug Testing Methods  ·  Immunoassay vs GC-MS/LC-MS/MS; where each fails Request
Vol. 22 Jul 2026 Oral Fluid Testing  ·  Observed, tamper-resistant; parent drug; shorter window Request
Vol. 11 Jul 2026 Specimen Validity Testing  ·  Creatinine, SG, pH, oxidant; dilution, substitution, adulteration Request
Vol. 38 Jul 2026 Creatinine Normalization  ·  Adjust drug levels for hydration; new use vs residual Request
About This Series

What Tox In Focus is for

Most clinical education on drug testing covers topics too broadly to be useful at the point of a specific decision — or too superficially to actually build understanding. Tox In Focus takes a different approach.

Each volume focuses entirely on a single topic: one drug, one drug class, one testing technology, one validity concept. The goal is a document that gives you everything you need to know about that specific thing — and nothing you don't — in 1–2 pages.

Volumes are written by Dr. William Bundy Jr., PharmD, and are available to subscribers or by direct request. Topics can also be requested — if your team needs a reference on something not yet in the series, reach out.

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Specific drugs & drug classes

Individual substances or classes — pharmacology, detection windows, immunoassay performance, clinical implications, and result interpretation.

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Testing technologies

How specific test types work, what they detect, where they fail, and what confirmatory testing looks like — explained for clinical and legal contexts.

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Validity & result interpretation

Creatinine, specific gravity, oxidizing adulterants, dilution — what the numbers mean, when to act on them, and when to look deeper.

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Request a topic

If your team has a specific topic that isn't yet covered, contact Dr. Bundy to discuss a custom volume or request a future series entry.

Get Access
Request a Tox In Focus volume.

Volumes are available by request. Reach out to get access to the existing series, request a specific topic, or ask about organizational subscriptions for your clinical team or program.