Medical Blog

Toxicity, Organophosphate

Introduction
Background

Organophosphate (OP) compounds are a diverse group of chemicals used in both domestic and industrial settings. Examples of organophosphates include: insecticides (malathion, parathion, diazinon, fenthion, dichlorvos, chlorpyrifos, ethion), nerve gases (soman, sarin, tabun, VX), ophthalmic agents (echothiophate, isoflurophate), and antihelmintics (trichlorfon). Herbicides (tribufos [DEF], merphos) are tricresyl phosphate–containing industrial chemicals. Read more…

Toxicity, Lidocaine
Introduction

Background

Lidocaine is an amide local anesthetic and a less commonly used antiarrhythmic that exerts its effects on nerve axon sodium channels, preventing depolarization.

Lidocaine toxicity occurs with unintended intravascular administration or with administration of an excessive dose. When lidocaine is used for regional nerve blocks, plasma levels are usually 3-5 mcg/mL. Toxicities may be observed at 6 mcg/mL, but more commonly occur once levels exceed 10 mcg/mL. Read more…

Toxicity, Lead

Introduction
Background

Lead is a natural compound that exists in elemental, inorganic, and organic forms. Lead is present in trace amounts in all soils, water, and foods. Lead is soft, malleable, blue-gray in color, and is highly resistant to corrosion. The melting point of lead is 327°C, and the vapor pressure of lead is 1000°C at 1.77 mm Hg. These properties, along with the poor ability of lead to conduct heat and electricity, probably contributed to the early discovery and persistent use of lead by humans. Lead pigments, for example, have been used in paints for more than 40,000 years, and lead utensils and artifacts, dating back 8000 years, have been recovered from Mediterranean excavation sites.
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Toxicity, Heroin

Introduction
Background

Heroin (diacetylmorphine) is a semisynthetic narcotic that was first synthesized in 1874. It was originally marketed as a safer, nonaddictive substitute to morphine. Soon after its introduction, heroin was realized to be clearly as addictive as morphine, prompting the US government to institute measures to control its use. By 1914, the Harrison Narcotics Act prohibited the use of heroin without a prescription. In 1920, the Dangerous Drugs Act prohibited the use of heroin altogether, thus driving it underground. In the United States, heroin remains one of the most frequently abused narcotics. Read more…

Toxicity, Cyanide

Introduction
Background

Cyanide, one of the most rapidly acting lethal poisons known to humankind, was a main constituent of Earth’s primordial atmosphere and probably played an important role in the development of life on Earth. It exists in nature in many different forms and may be found in a number of fruits and vegetables in the form of cyanogenic glycosides.
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Toxicity, Cone Shell Neurotoxin
Introduction
Background

Cone shells, members of the family Conidae, are marine snails prized for their beautiful, intricately designed shells. However, these molluscs also produce potent neurotoxins and sting when disturbed. Cone shells are found in the Indo-Pacific region and along the southern Australian coast. They usually live in intertidal regions, where they are easily found among the rocks and corals exposed at low tide, but they have also been found in waters as deep as 30 meters. Read more…

Toxicity, Cocaine
Introduction

Background

Cocaine is derived from Erythroxylon coca, a shrub endemic to the Andes, Mexico, West Indies, and Indonesia. The people of the Andes held the shrub in religious reverence and buried their dead with bags of coca leaves. The stimulant effects of the coca leaves are believed to have played a major role in the advancement of the Inca civilization, providing the Incas with the energy and motivation to realize dramatic architectural and social achievements despite the barren, icy, cold, and oxygen-poor environment they inhabited. The Spanish conquistadors quickly became enamored of the euphoric effects of the plant and introduced the shrub to the Europeans, who developed a fondness for the taste and sensations it generated.
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Toxicity, Benzodiazepine
Introduction

Background

Since initial development in the 1950s, benzodiazepine has become popular in the treatment of various medical disorders and as a drug of abuse.1, 2 Benzodiazepine overdoses (usually combined with alcohol) are commonly observed in emergency departments (EDs) and intensive care units (ICUs).
Pathophysiology
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Toxicity, Barbiturate
Introduction

Background

Barbiturates are a class of organic compounds that were developed in the late 19th century for the treatment of anxiety and insomnia. These agents were originally touted as safer alternatives to bromides, but soon after their introduction, their toxic effects and their low therapeutic index became clear, eventually leading to their replacement by the much safer benzodiazepines. Read more…

Toxicity, Arsenic
Introduction

Background

Arsenic is a heavy metal with a name derived from the Greek word arsenikon, meaning potent. Arsenic is ubiquitous, found in air, water, fuels, and marine life. The daily human intake of arsenic contained in food ranges from 0.5-1 mg, with the greatest concentrations coming from fish and crustaceans. Arsenic has been used for a variety of purposes. For a long time, arsenic was considered the perfect poison because it is odorless, tasteless, and resembles sugar. Throughout history, arsenic was thought to have claimed the lives of many, including Britanicus, Pope Pius III, Pope Clemente XIV, and Napoleon Bonaparte. Arsenic has been used for the treatment of ulcers, tuberculosis, syphilis, and many other ailments. More recently, arsenic has been used as an insecticide, fungicide, rodenticide, and wood preservative. Arsenic also has been used to manufacture glass and semiconductors.
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