Insecticide Poisoning

Definition

Insecticides Insecticides Pesticides designed to control insects that are harmful to man. The insects may be directly harmful, as those acting as disease vectors, or indirectly harmful, as destroyers of crops, food products, or textile fabrics. Trypanosoma cruzi/Chagas disease are substances used to kill insects or prevent them from destructive behaviors.

• Insecticides Insecticides Pesticides designed to control insects that are harmful to man. The insects may be directly harmful, as those acting as disease vectors, or indirectly harmful, as destroyers of crops, food products, or textile fabrics. Trypanosoma cruzi/Chagas disease are classified as pesticides, defined by the U.S. Environmental Protection Agency (EPA) as any substance intended for preventing, destroying, or repelling any pest. 
• The term “pesticides” also applies to fungicides, rodenticides, bactericides, and herbicides.
• Insecticides Insecticides Pesticides designed to control insects that are harmful to man. The insects may be directly harmful, as those acting as disease vectors, or indirectly harmful, as destroyers of crops, food products, or textile fabrics. Trypanosoma cruzi/Chagas disease work by interfering with biologic mechanisms in insects. 
• Many organisms share similar biologic mechanisms, so effects of pesticides are often nonspecific to organism type.

Dichlorodiphenyltrichloroethane (DDT)

Etiology

Dichlorodiphenyltrichloroethane:

• Commonly known as DDT
• Colorless, tasteless, crystalline organochlorine
• Uses:
  • Treat insect spread of malaria Malaria Malaria is an infectious parasitic disease affecting humans and other animals. Most commonly transmitted via the bite of a female Anopheles mosquito infected with microorganisms of the Plasmodium genus. Patients present with fever, chills, myalgia, headache, and diaphoresis. Plasmodium/Malaria, yellow fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, and insect-vectored diseases
  • Insect control in crop and livestock production and buildings
• 1st of the modern synthetic insecticides Insecticides Pesticides designed to control insects that are harmful to man. The insects may be directly harmful, as those acting as disease vectors, or indirectly harmful, as destroyers of crops, food products, or textile fabrics. Trypanosoma cruzi/Chagas disease in the 1940s but use was stopped by EPA in 1972 because of its adverse effects on wildlife and the environment
• Still used where malaria Malaria Malaria is an infectious parasitic disease affecting humans and other animals. Most commonly transmitted via the bite of a female Anopheles mosquito infected with microorganisms of the Plasmodium genus. Patients present with fever, chills, myalgia, headache, and diaphoresis. Plasmodium/Malaria remains a major health problem with high mortality Mortality All deaths reported in a given population. Measures of Health Status
• Highly persistent chemical:
  • Soil half-life Half-Life The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity. Pharmacokinetics and Pharmacodynamics: 2–15 years
  • Human half-life Half-Life The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity. Pharmacokinetics and Pharmacodynamics: 3–6 years

Pathogenesis

• DDT exposure:
  • Humans are exposed usually through ingestion of meat, fish FISH A type of in situ hybridization in which target sequences are stained with fluorescent dye so their location and size can be determined using fluorescence microscopy. This staining is sufficiently distinct that the hybridization signal can be seen both in metaphase spreads and in interphase nuclei. Chromosome Testing, and dairy products.
  • Can also be absorbed from direct contact and inhalation
• DDT is converted to metabolites including dichlorodiphenyldichloroethane (DDE) → DDT and DDE are stored in adipose tissues
• Effects:
  • Associations of DDT and tumor Tumor Inflammation development are seen in laboratory animals Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, animalia was one of the kingdoms. Under the modern three domain model, animalia represents one of the many groups in the domain eukaryota. Cell Types: Eukaryotic versus Prokaryotic, but there is no clear evidence that it causes cancer in humans. 
  • Oxidative stress Oxidative stress A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products. Cell Injury and Death could be a key factor in hepatocarcinogenesis.
  • Produces neurotoxicity by causing delays in the closing of the Na⁺ channel
• Considered an endocrine-disrupting chemical (EDC), causing reproductive toxicity Toxicity Dosage Calculation by affecting estrogenic activity

Clinical presentation

• Neurotoxicity:
  • Paresthesias Paresthesias Subjective cutaneous sensations (e.g., cold, warmth, tingling, pressure, etc.) that are experienced spontaneously in the absence of stimulation. Posterior Cord Syndrome around the mouth
  • Dizziness Dizziness An imprecise term which may refer to a sense of spatial disorientation, motion of the environment, or lightheadedness. Lateral Medullary Syndrome (Wallenberg Syndrome)
  • Confusion
  • Incoordination/ ataxia Ataxia Impairment of the ability to perform smoothly coordinated voluntary movements. This condition may affect the limbs, trunk, eyes, pharynx, larynx, and other structures. Ataxia may result from impaired sensory or motor function. Sensory ataxia may result from posterior column injury or peripheral nerve diseases. Motor ataxia may be associated with cerebellar diseases; cerebral cortex diseases; thalamic diseases; basal ganglia diseases; injury to the red nucleus; and other conditions. Ataxia-telangiectasia
  • Tremors
  • Seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures
• Nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics/ vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia
• Lethargy Lethargy A general state of sluggishness, listless, or uninterested, with being tired, and having difficulty concentrating and doing simple tasks. It may be related to depression or drug addiction. Hyponatremia
• May be related to hepatotoxicity Hepatotoxicity Acetaminophen and carcinogenicity (chronic)

Diagnosis and management

• Diagnosis is clinical and based mainly on a history of exposure and symptoms. 
• Levels can be measured in blood, urine, semen, fat, and breast milk.
• Management:
  • Decontamination
  • Supportive care, observation, and symptomatic treatment/relief are the mainstays of therapy. 
  • No antidote Antidote An antidote is a substance that counteracts poisoning or toxicity. Substances that can cause poisoning include heavy metals (from occupation, treatments, or diet), alcohols, environmental toxins, and medications. Antidotes of Common Poisonings

Organophosphate Toxicity

Etiology

Organophosphates:

• Irreversible cholinesterase Cholinesterase Liver Function Tests inhibitors
• Examples of organophosphate (OP) chemicals:
  • Insecticides Insecticides Pesticides designed to control insects that are harmful to man. The insects may be directly harmful, as those acting as disease vectors, or indirectly harmful, as destroyers of crops, food products, or textile fabrics. Trypanosoma cruzi/Chagas disease: malathion Malathion A wide spectrum aliphatic organophosphate insecticide widely used for both domestic and commercial agricultural purposes. Cholinomimetic Drugs, parathion, diazinon, fenthion, dichlorvos, chlorpyrifos, ethion
  • Herbicides: tribufos (DEF), merphos
  • Nerve gases: soman, sarin Sarin An organophosphorus ester compound that produces potent and irreversible inhibition of cholinesterase. It is toxic to the nervous system and is a chemical warfare agent. Cholinomimetic Drugs, tabun, VX
  • Ophthalmic agents: echothiophate, isoflurophate Isoflurophate A diisopropyl-fluorophosphate which is an irreversible cholinesterase inhibitor used to investigate the nervous system. Cholinomimetic Drugs
  • Anthelminthics: trichlorfon
  • Industrial chemical (plasticizer): tricresyl phosphate Phosphate Inorganic salts of phosphoric acid. Electrolytes

Pathophysiology

• Inhibit the cholinesterase Cholinesterase Liver Function Tests enzyme in the synaptic cleft Synaptic cleft Synapses and Neurotransmission
• Irreversible phosphorylation Phosphorylation The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety. Post-translational Protein Processing of acetylcholinesterase (AChE) by inhibition of the AChE enzyme, which is present in:
  • Parasympathetic and sympathetic ganglia
  • Parasympathetic muscarinic terminal junctions
  • Sympathetic fibers located in sweat glands Sweat glands Sweat-producing structures that are embedded in the dermis. Each gland consists of a single tube, a coiled body, and a superficial duct. Soft Tissue Abscess
  • Nicotinic receptors Receptors Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors at the skeletal neuromuscular junction Neuromuscular junction The synapse between a neuron and a muscle. Skeletal Muscle Contraction
• Persistently ↑ acetylcholine Acetylcholine A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system. Receptors and Neurotransmitters of the CNS levels due to AChE inhibition leads to ↑ neurotransmitter signaling.

Clinical presentation

• Presents as a cholinergic toxidrome Toxidrome A toxidrome describes a group of signs, symptoms, and/or characteristic effects associated with exposure to a particular substance or class of substances. General Principles of Toxidromes
• Pinpoint pupils
• Sweating, salivation
• Bronchoconstriction
• Vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia 
• Diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea
• CNS stimulation then depression
• Muscle fasciculations Fasciculations Involuntary contraction of the muscle fibers innervated by a motor unit. Fasciculations may be visualized as a muscle twitch or dimpling under the skin, but usually do not generate sufficient force to move a limb. They may represent a benign condition or occur as a manifestation of motor neuron disease or peripheral nervous system diseases. Polyneuropathy, weakness, paralysis
• Death from respiratory failure Respiratory failure Respiratory failure is a syndrome that develops when the respiratory system is unable to maintain oxygenation and/or ventilation. Respiratory failure may be acute or chronic and is classified as hypoxemic, hypercapnic, or a combination of the two. Respiratory Failure

Diagnosis

• Primarily a clinical diagnosis based on history and examination. 
• Some organophosphorus agents have a distinct petroleum or garlic-like odor.
• Confirmation can be confirmed by measurement of cholinesterase Cholinesterase Liver Function Tests activity:
  • RBC AChE and plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products cholinesterase Cholinesterase Liver Function Tests (PChE) or butyrylcholinesterase (BuChE) levels can both be used.
  • RBC AChE correlates with degree of toxicity Toxicity Dosage Calculation.

Management

• Airway Airway ABCDE Assessment, breathing, and circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment (ABC) assessment
• Decontamination:
  • Removal of clothes, irrigation or washing of exposed areas
  • Activated charcoal Charcoal An amorphous form of carbon prepared from the incomplete combustion of animal or vegetable matter, e.g., wood. The activated form of charcoal is used in the treatment of poisoning. Antidotes of Common Poisonings (AC; within an hour of ingestion)
  • PPE: Use neoprene gloves and gowns, as hydrocarbons can penetrate nonpolar substances such as latex and vinyl.
  • Charcoal Charcoal An amorphous form of carbon prepared from the incomplete combustion of animal or vegetable matter, e.g., wood. The activated form of charcoal is used in the treatment of poisoning. Antidotes of Common Poisonings cartridge masks for respiratory protection
  • Irrigate the eyes of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship who have had ocular exposure.
• Supportive care:
  • IV fluids IV fluids Intravenous fluids are one of the most common interventions administered in medicine to approximate physiologic bodily fluids. Intravenous fluids are divided into 2 categories: crystalloid and colloid solutions. Intravenous fluids have a wide variety of indications, including intravascular volume expansion, electrolyte manipulation, and maintenance fluids. Intravenous Fluids
  • Intubation Intubation Peritonsillar Abscess:
    • Avoid succinylcholine Succinylcholine A quaternary skeletal muscle relaxant usually used in the form of its bromide, chloride, or iodide. It is a depolarizing relaxant, acting in about 30 seconds and with a duration of effect averaging three to five minutes. Succinylcholine is used in surgical, anesthetic, and other procedures in which a brief period of muscle relaxation is called for. Cholinomimetic Drugs because it is metabolized by AChE.
    • May be necessary in cases of respiratory distress due to laryngospasm Laryngospasm Hypoparathyroidism, bronchospasm Bronchospasm Asthma Drugs, bronchorrhea, or seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures
• Seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures: Give benzodiazepines Benzodiazepines Benzodiazepines work on the gamma-aminobutyric acid type A (GABAA) receptor to produce inhibitory effects on the CNS. Benzodiazepines do not mimic GABA, the main inhibitory neurotransmitter in humans, but instead potentiate GABA activity. Benzodiazepines.
• Antidotal therapy:
  • Atropine Atropine An alkaloid, originally from atropa belladonna, but found in other plants, mainly solanaceae. Hyoscyamine is the 3(s)-endo isomer of atropine. Anticholinergic Drugs:
    • Binds to muscarinic receptors Muscarinic Receptors Asthma Drugs, temporarily blocking them and reducing cholinergic effect(s)
    • Dosing titrated to clearance of respiratory secretions and cessation of bronchoconstriction
  • Pralidoxime Pralidoxime Various salts of a quaternary ammonium oxime that reconstitute inactivated acetylcholinesterase, especially at the neuromuscular junction, and may cause neuromuscular blockade. They are used as antidotes to organophosphorus poisoning as chlorides, iodides, methanesulfonates (mesylates), or other salts. General Principles of Toxidromes (2-PAM):
    • Effective in both muscarinic and nicotinic effects
    • Reactivates AChE but has a transient inhibitory effect on the enzyme, so should be given in conjunction with atropine Atropine An alkaloid, originally from atropa belladonna, but found in other plants, mainly solanaceae. Hyoscyamine is the 3(s)-endo isomer of atropine. Anticholinergic Drugs

Mnemonics

SLUDGE BBB BBB Specialized non-fenestrated tightly-joined endothelial cells with tight junctions that form a transport barrier for certain substances between the cerebral capillaries and the brain tissue. Nervous System: Histology (muscarinic effects):

• Salivation
• Lacrimation (crying is key feature)
• Urination
• Defecation ( diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea)
• GI cramping (distress)
• Emesis
• Bronchospasm
• Bronchorrhea
• Bradycardia

DUMBELS (muscarinic effects):

• Defecation
• Urination
• Miosis
• Bronchorrhea/ bronchospasm Bronchospasm Asthma Drugs/ bradycardia Bradycardia Bradyarrhythmia is a rhythm in which the heart rate is less than 60/min. Bradyarrhythmia can be physiologic, without symptoms or hemodynamic change. Pathologic bradyarrhythmia results in reduced cardiac output and hemodynamic instability causing syncope, dizziness, or dyspnea. Bradyarrhythmias
• Emesis
• Lacrimation
• Salivation 

Carbamate Toxicity

Etiology

Carbamates:

• Derivatives of carbamic acid
• Structurally and mechanistically similar to organophosphates (which are derivatives of phosphoric acid Phosphoric Acid Caustic Ingestion (Cleaning Products))
• Includes compounds such as carbaryl, methomyl, and carbofuran 
• Carbaryl is the 2nd most widely detected insecticide in surface waters in the United States:
  • Low mammalian toxicity Toxicity Dosage Calculation
  • Short half-life Half-Life The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity. Pharmacokinetics and Pharmacodynamics in the environment
  • Effective against 160 harmful insects

Pathophysiology

• Toxic exposures: dermal, inhalational, and GI
• While carbamates have a similar mechanism of action to that of organophosphates, they bind BIND Hyperbilirubinemia of the Newborn to AChE reversibly. 
• Similar toxicologic presentation to OP poisonings but often with a duration of < 24 hours
• Mechanism:
  • Inhibits the AChE enzyme by carbamylation of AChE at neuronal synapses and neuromuscular junctions →  overstimulation of the nervous system Nervous system The nervous system is a small and complex system that consists of an intricate network of neural cells (or neurons) and even more glial cells (for support and insulation). It is divided according to its anatomical components as well as its functional characteristics. The brain and spinal cord are referred to as the central nervous system, and the branches of nerves from these structures are referred to as the peripheral nervous system. Nervous System: Anatomy, Structure, and Classification 
  • Carbamate bonds are eventually hydrolyzed in 24–48 hours → AChE broken down to acetic acid + choline → cessation of neurotransmitter signaling

Clinical presentation

• Presents as a cholinergic toxidrome Toxidrome A toxidrome describes a group of signs, symptoms, and/or characteristic effects associated with exposure to a particular substance or class of substances. General Principles of Toxidromes (mnemonics similar to OP)
• Pinpoint pupils
• Sweating, salivation
• Bronchoconstriction
• Vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia 
• Diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea
• CNS stimulation then depression
• Muscle fasciculations Fasciculations Involuntary contraction of the muscle fibers innervated by a motor unit. Fasciculations may be visualized as a muscle twitch or dimpling under the skin, but usually do not generate sufficient force to move a limb. They may represent a benign condition or occur as a manifestation of motor neuron disease or peripheral nervous system diseases. Polyneuropathy, weakness, paralysis
• Death from respiratory failure Respiratory failure Respiratory failure is a syndrome that develops when the respiratory system is unable to maintain oxygenation and/or ventilation. Respiratory failure may be acute or chronic and is classified as hypoxemic, hypercapnic, or a combination of the two. Respiratory Failure

Diagnosis and management

• Diagnosis is clinical based on history of exposure and symptoms. 
• Laboratory testing can be done, but do not delay potentially lifesaving treatments while waiting on results.
• Confirmation can be done by measurement of cholinesterase Cholinesterase Liver Function Tests activity:
  • BuChE and RBC AChE levels
  • RBC AChE rapidly returns to normal in carbamate poisoning.
• Management:
  • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship who are asymptomatic 12 hours after exposure can be discharged.
  • Hospitalize all symptomatic patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship for at least 48 hours in a high-acuity setting.
  • Decontamination (similar to management of OP poisoning)
  • Atropine Atropine An alkaloid, originally from atropa belladonna, but found in other plants, mainly solanaceae. Hyoscyamine is the 3(s)-endo isomer of atropine. Anticholinergic Drugs and benzodiazepines Benzodiazepines Benzodiazepines work on the gamma-aminobutyric acid type A (GABAA) receptor to produce inhibitory effects on the CNS. Benzodiazepines do not mimic GABA, the main inhibitory neurotransmitter in humans, but instead potentiate GABA activity. Benzodiazepines are primary medical treatments.
  • Intubation Intubation Peritonsillar Abscess may be necessary in cases of respiratory distress due to laryngospasm Laryngospasm Hypoparathyroidism, bronchospasm Bronchospasm Asthma Drugs, bronchorrhea, or seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures.
  • Pralidoxime Pralidoxime Various salts of a quaternary ammonium oxime that reconstitute inactivated acetylcholinesterase, especially at the neuromuscular junction, and may cause neuromuscular blockade. They are used as antidotes to organophosphorus poisoning as chlorides, iodides, methanesulfonates (mesylates), or other salts. General Principles of Toxidromes can be used in carbamate poisoning but not in carbaryl poisoning (associated with poor outcomes).

Clinical Relevance

• Caustic ingestion Caustic Ingestion Caustic agents are acidic or alkaline substances that damage tissues severely if ingested. Alkali ingestion typically damages the esophagus via liquefactive necrosis, whereas acids cause more severe gastric injury leading to coagulative necrosis. Caustic Ingestion (Cleaning Products): Acidic or alkaline substances Alkaline Substances Caustic Ingestion (Cleaning Products) damage tissues severely if ingested. Alkali ingestion typically damages the esophagus Esophagus The esophagus is a muscular tube-shaped organ of around 25 centimeters in length that connects the pharynx to the stomach. The organ extends from approximately the 6th cervical vertebra to the 11th thoracic vertebra and can be divided grossly into 3 parts: the cervical part, the thoracic part, and the abdominal part. Esophagus: Anatomy. Acids Acids Chemical compounds which yield hydrogen ions or protons when dissolved in water, whose hydrogen can be replaced by metals or basic radicals, or which react with bases to form salts and water (neutralization). An extension of the term includes substances dissolved in media other than water. Acid-Base Balance cause more severe gastric injury. In large amounts and high concentrations, caustic ingestion Caustic Ingestion Caustic agents are acidic or alkaline substances that damage tissues severely if ingested. Alkali ingestion typically damages the esophagus via liquefactive necrosis, whereas acids cause more severe gastric injury leading to coagulative necrosis. Caustic Ingestion (Cleaning Products) also leads to severe injuries such as shock Shock Shock is a life-threatening condition associated with impaired circulation that results in tissue hypoxia. The different types of shock are based on the underlying cause: distributive (↑ cardiac output (CO), ↓ systemic vascular resistance (SVR)), cardiogenic (↓ CO, ↑ SVR), hypovolemic (↓ CO, ↑ SVR), obstructive (↓ CO), and mixed. Types of Shock, abdominal rigidity Abdominal Rigidity Acute Abdomen, respiratory distress, and/or altered mental status Altered Mental Status Sepsis in Children. Diagnosis is by laboratory tests, abdominal and chest imaging, and endoscopy Endoscopy Procedures of applying endoscopes for disease diagnosis and treatment. Endoscopy involves passing an optical instrument through a small incision in the skin i.e., percutaneous; or through a natural orifice and along natural body pathways such as the digestive tract; and/or through an incision in the wall of a tubular structure or organ, i.e. Transluminal, to examine or perform surgery on the interior parts of the body. Gastroesophageal Reflux Disease (GERD). Management involves stabilizing the patient, decontamination, and supportive therapy. Severe injury may require surgery.
• Herbicides: chemical substances used to kill or control the growth of unwanted plants Plants Cell Types: Eukaryotic versus Prokaryotic. Important herbicides that can affect humans include paraquat Paraquat A poisonous bipyridylium compound used as contact herbicide. Contact with concentrated solutions causes irritation of the skin, cracking and shedding of the nails, and delayed healing of cuts and wounds. Herbicide Poisoning, Agent Orange Agent orange A herbicide that contains equal parts of 2, 4-dichlorophenoxyacetic acid (2, 4-d) and 2, 4, 5-trichlorophenoxyacetic acid (2, 4, 5-t), as well as traces of the contaminant 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin. Herbicide Poisoning, glyphosate, and organophosphates. Different types of herbicides result in different clinical manifestations and have various toxicity Toxicity Dosage Calculation levels. Exposure can be dermal or by inhalation or ingestion. Management consists of stabilizing the patient and decontamination. Organophosphate toxicity Toxicity Dosage Calculation has an antidote Antidote An antidote is a substance that counteracts poisoning or toxicity. Substances that can cause poisoning include heavy metals (from occupation, treatments, or diet), alcohols, environmental toxins, and medications. Antidotes of Common Poisonings. Treatment revolves around supportive care dependent on the involved organ system. 
• Toxidrome Toxidrome A toxidrome describes a group of signs, symptoms, and/or characteristic effects associated with exposure to a particular substance or class of substances. General Principles of Toxidromes: group of clinical signs and symptoms associated with toxic ingestion or exposure. There are 5 traditional toxidromes Toxidromes A toxidrome is a group of clinical signs and symptoms associated with a toxic ingestion or exposure. There are 5 traditional toxidromes: anticholinergic, cholinergic, opioid, sympathomimetic, and sedative-hypnotic. General Principles of Toxidromes: anticholinergic Anticholinergic Anticholinergic drugs block the effect of the neurotransmitter acetylcholine at the muscarinic receptors in the central and peripheral nervous systems. Anticholinergic agents inhibit the parasympathetic nervous system, resulting in effects on the smooth muscle in the respiratory tract, vascular system, urinary tract, GI tract, and pupils of the eyes. Anticholinergic Drugs, cholinergic, opioid Opioid Compounds with activity like opiate alkaloids, acting at opioid receptors. Properties include induction of analgesia or narcosis. Constipation, sympathomimetic Sympathomimetic Sympathomimetic drugs, also known as adrenergic agonists, mimic the action of the stimulators (α, β, or dopamine receptors) of the sympathetic autonomic nervous system. Sympathomimetic drugs are classified based on the type of receptors the drugs act on (some agents act on several receptors but 1 is predominate). Sympathomimetic Drugs, and sedative-hypnotic. Toxidromes Toxidromes A toxidrome is a group of clinical signs and symptoms associated with a toxic ingestion or exposure. There are 5 traditional toxidromes: anticholinergic, cholinergic, opioid, sympathomimetic, and sedative-hypnotic. General Principles of Toxidromes often arise from ingestion of overdose amounts, accumulation of medications with resultant elevated serum levels, adverse drug reactions, or interactions between ≥ 2 medications.  Diagnosis is by clinical findings based on medication and exposure history and physical examination.