2025 Medical Review Officer Online Course with Live Discussion (Includes Digital Syllabus)-Tab 8

Video Transcription

Video Summary

The lecture covers comprehensive aspects of drug toxicology and testing interpretation. A negative drug test does not guarantee absence of drug use, as factors like cutoff limits, dilution, or adulteration affect results. Positive urine results only confirm presence above cutoffs, not usage timing, amount, or impairment.<br /><br />Marijuana discussion highlights its many cannabinoids, chiefly Delta-9-THC and its metabolites, with detection influenced by usage method. Passive inhalation is not a viable cause of positive tests at standard cutoffs. Medicinal marijuana's complexity involves the "entourage effect," combining many compounds.<br /><br />Cocaine metabolizes primarily to benzoylecgonine, detectable for days; ingestion routes and stability impact detection. Herbal teas containing coca are noted but not valid excuses in US testing. Opiates/opioids include natural (morphine, codeine) and synthetic types (fentanyl). Morphine levels can arise from poppy seed ingestion, necessitating specific cutoff levels to distinguish use from food sources. Heroin metabolizes rapidly through 6-acetylmorphine to morphine; the former remains a specific heroin marker.<br /><br />Amphetamines discussed include methamphetamine, amphetamine, MDMA, and their metabolic nuances. Chirality separates illicit D-methamphetamine from over-the-counter L-forms. Designer stimulants like cathinones have emerged as illicit alternatives. Benzodiazepines, barbiturates, methadone, anabolic steroids, and emerging drugs like fentanyl and propofol are also addressed, reflecting evolving drug testing needs across clinical, workplace, and forensic contexts.

Keywords

drug toxicology

drug testing interpretation

marijuana cannabinoids

cocaine metabolites

opiates and opioids

amphetamine and designer stimulants

emerging drugs in testing