What’s new in Scientific American Medicine this week:

  • Cholinergic Toxicity
  • Drugs of Abuse
  • Caustics
  • Psychoactive Medications


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Acetylcholinesterase hydrolysis of acetylcholine.

Cholinergic Toxicity

STEPHEN B. BIRD, MD
Division of Medical Toxicology, University of Massachusetts Medical School, Worcester, MA

 

Cholinergic drugs exert their functions by inhibiting acetylcholinesterase, the enzyme responsible for hydrolyzing acetylcholine and ending neuronal or neuromuscular neurotransmission. These compounds are used in clinical medicine to treat various disorders, as pesticides, and as weapons of mass destruction. This review describes the drugs that affect the cholinergic system and discusses stabilization, diagnosis and definitive therapy, principles and controversies of definitive care, and disposition and outcomes for these agents.

 


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Substances ranked according to weighted harm score on a normalized scale from 0 being no harm to 100 being extreme harm to self and others.

Drugs of Abuse

MATTHEW D. ZUCKERMAN, MD
Department of Emergency Medicine, Medical Toxicology, University of Colorado Anschutz Medical Campus, Aurora, CO
KAVITA BABU, MD, FACEP, FACMT
Division of Medical Toxicology, Associate Professor, Department of Emergency Medicine, University of Massachusetts Medical School, Worcester, MA

 

In the last decade, dozens of novel agents of abuse have emerged, many of them chemical variants of the naturally occurring cathinone found in the plant Catha edulis. Synthetic cathinones may be sold under the name of bath salts or plant food to subvert legal restrictions on their use. Their beta-ketone amphetamine structure results in their amphetamine-like sympathomimetic effects. However, synthetic cathinones also seem to modulate serotonin release, resulting in various psychoactive effects. Toxicity in patients using synthetic cathinones varies from euphoria and intoxication, to florid violent hallucinations, hyperthermia, rhabdomyolysis, seizures, and death. Unlike many other street drugs, synthetic cathinones are often known more commonly by their street name (e.g., bath salts), with the exact chemical composition changing over time in response to legal pressures.

 


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A hydrofluoric acid burn of the hand. By Dr. Watchorn (Dr. Watchorn) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)%5D, via Wikimedia Commons

Caustics

LYNN A. FARRUGIA MD
Resident, University of Massachusetts Medical School Emergency Medicine Residency Program, Worcester, MA
KAVITA M. BABU, MD, FACEP, FACMT
Fellowship Director, Division of Medical Toxicology, Associate Professor, Department of Emergency Medicine, University of Massachusetts Medical School, Worcester, MA

 

The most common route of hydrofluoric acid exposure is cutaneous contact, often due to damaged or insufficient protective gear. Delayed pain is the hallmark of hydrofluoric acid burns. Timing is typically related to the concentration of fluoride in the material; high concentrations of 50 to 70% have a much more rapid onset of pain of just a few minutes, whereas concentrations lower than 20% may take up to 24 hours to develop symptoms. Burns may progress over hours from pallor, erythema, and edema to bullae, ulceration, blue or gray discoloration, and necrosis. Systemic fluoride toxicity can occur from significant dermal exposure. Common products containing hydrofluoric acid include rust removers, glass etching, porcelain and tile cleaners, and automobile wheel cleaners.

 


Psychoactive Medications

MARK J. NEAVYN, MD
Director of Medical Toxicology, Department of Emergency Medicine, Hartford Hospital, Hartford, CT
KAVITA M. BABU, MD, FACEP, FACMT
Fellowship Director, Division of Medical Toxicology, Associate Professor, Department of Emergency Medicine, University of Massachusetts Medical School, Worcester, MA

 

Psychoactive medications are defined as medications that affect the central nervous system neurotransmitter pathways with the intention to modulate mood or consciousness. This broad category of medications includes sedative-hypnotic agents such as benzodiazepines and barbiturates, antidepressants, neuroleptics, and mood stabilizers. The principal source of exposure for these medications is through prescription drug use and misuse.

 


SAM-CTA

WRITTEN BY

decker
The Decker Team