Clinical Toxicology

Fiddleback spider

brown recluse

Bath salts structurally resemble ______.

methamphetamines

Is poinsetta poisonous?

no, its a myth but it is probably a choking hazard

How to treat ingestion of isopropyl alcohol?

supportive, maybe HD

What are the signs and symptoms of aspirin toxicity?

symptoms: N/V, abd pain, ringing in ears signs: restless, diaphoretic, tachypnic, epigastric tenderness

Toxalbumins inhibit ribosomal functions and lead to multi-system organ failure. What is included in this group?

- Jequirty bean - Mistletoe - Castor beans (ricin)

Radiation exposure will incorporate into which 4 major areas in the body?

- thyroid - liver - lungs - bones

What are the three basic factors that determine the exposure to radiation?

1. Time 2. Distance 3. Shielding

What's the mechanism of cyanide?

Cyanide disrupts ATP production in the mitochondria

_________ is the primary target for cell damage from ionizing radiation.

DNA

Antidote for Methemaglobin

Methylene Blue

Feverfew is marketed for _______.

+ headache + maybe arthritis

Antidote for Lead

DMSA

Antidote for Iron

Deferoxime

How to treat ingestion of methanol?

Fomeprizole

What enzyme in black window venom is responsible for opening cation channels and causing blockade of neuromuscular junctions?

alpha-latrotoxin

What do you NOT give for TCA toxicity?

physostigmine (this is a cholinergic, but do not use it) Beta blockers CCB Antiarrhythmics 1C, 1A

Kava kava is marketed for _______.

+ decrease anxiety and tension + decrease restlessness + reduce insomnia

Gingko biloba is marketed for _______.

+ improve age related memory impairment + improve visual field in glaucoma + reduce PMS

Ginseng is marketed for _______.

+ improve cognitive function + enhance athletic performance + improve mood

Garlic is marketed for _______.

+ prevent heart disease + lower cholesterol + lower blood pressure + improve clotting disorders

Ginger is marketed for _______.

+ prevent motion sickness + reduce morning sickness + reduce nausea + digestive aid

Echinacea is marketed for _______.

+ reduce cold symptoms + boost immune system + heal wounds (immune system stuff)

Evening primrose is marketed for _______.

+ reduce hot flashes + reduce breast pain + treat osteoporosis, maybe RA

Saw Palmetto is marketed for _______.

+ treat BPH + Improve prostate health + enhance sexual vigor + enhance breast size

St Johns Wort is marketed for _______.

+ treat depression + treat OCD + treat seasonal affective disorder

Your best friend is bitten by a snake. What should you NOT do?

- Do not cut/suction wound - Do not ice the bite - Do not use tourniquets - Do no use extraction devices/techniques - Do not pressure immobilize - Shock therapy (electricity)

What are some treatment strategies in the ER for bee stings?

- IVF bolus (anaphylaxis increases vascular permability) - diphenydramine - steroids - H2 antagonist (cimetadine) - epinephrine (severe) - albuterol nebs for bronchospasm

Your best friend is bitten by a snake while y'all are hiking in July. What should you do?

- Put victim at rest - Reassurance - Attempt to ID snake / take a pic - Immobilize affected part - Watch for uptoward reaction - Record edema progression every 15 minutes - Transport to nearest medical facility - Also, probably remove rings/watches

If a snake bit your right now, what would you expect to happen?

- Symptoms begin at bite site, with pain starting immediately, and edema beginning soon after envenomation (also, there will be fang marks) - most bites are subcutaneous but some can be deeper, possibly leading to muscle necrosis - blisters / vesicles can occur within 12 hours

Arsenic is a heavy metal that structurally mimics phosphate, leading to disruptions in DNA processes and it inhibits pyruvate dehydrogenase. With all this, it is no wonder that symptoms of chronic exposure include:

- abdominal pain - N/V - diarrhea - stomatitis - sensory neuropathy - cancers

Sodium channels activating plant toxins cause cardiac arrhythmias and include:

- aconite - monkshood - wolfbane - soldier's cap

What are the anticholinergic plant based toxins ?

- belladonna alkaloids - jimson weed - angel's trumpet (red, blind, hot, dry, mad, fast, full - hallucinations)

What is the mechanisms of cocaine?

- blocks reuptake of norepi, dopamine ---> hyperthermia - blocks fast Na channels (widen QRS, arrhythmias) - increase thrombogenesis (clots anywhere)

What are the mechanisms of heroin?

- converted to morphine - heroin more potent and euphorogenic than morphine - ALL OPIOIDS acts on Mu receptors causing euphoria, resp depression, analgesia - nalaxone antagonizes Mu

What are some pre-hospital treatment strategies for bee stings?

- diphenydramine oral - clean wound, remove stinger with credit card - ice / cool compress - elevate extremity

You should discourage herbal supplements in ________.

- elderly - pregnant, breastfeeding - pediatrics - pts on lots of prescription meds (interactions) - pts having surgery - conditions that have a proven medical treatment

What are the contraindications of gastric lavage (stomach pump)?

- loss of protective airway reflexes (obtunded, unconscious) - acid or base ingestion - hydrocarbon ingestion with risk of aspiration - patient at risk of hemorrhage / perforation

What plants are known to have cardiac glycosides?

- oleander - lily of the valley - foxglove Inhibit Na/K pump

What causes contact dermatitis?

- pepper plant - poison ivy, oak, sumac (urshiol is degraded in water, wash immediately)

What are the treatment principles of radiation exposure?

- reduce absorption and internal deposition (remove clothes) - enhance excretion of absorbed contaminants - Prussian blue ion exchange - chelation agents (Ca-DTPA, Zn-DTPA) - potassium iodine (blocks thyroid uptake)

Describe treatment of salicylate toxicity?

- remove unabsorbed drug (lavage, charcoal) - IV bicarbonate (in IVF?) to alkalinize urine to create ion trapping and eliminate salicylates via urine - HD can remove (use in renal failure, CNS toxicity)

What are the metabolic disturbance in aspirin overdose and describe the mechanisms by which they occur?

- salicylates will increase glycolysis, glucose metabolism - causes fat catabolism / ketone production - uncouples oxidative phosphorylation - interrupts kreb's cycle - get anion gap metabolic acidosis --> increased RR --> blow off CO2 --> respiratory alkalosis

How do you manage nerve agent exposure ?

- skin decontamination (remove clothes, wash) - atropine (dries secretions, does not help muscle weakness) - pralidoxime (helps muscle weakness)

How should organophosphate poisoning be managed ?

- suction and intubate - GI decontamination with multi-dose activated charcoal - skin decontamination (remove clothes)

What plants produce calcium oxalate crystals?

- typical office ivy - Dumb plant - Elephant ears if you chew them, it will be uncomfortable.

What are the contraindications for using activated charcoal?

- unprotected airway (can be deadly in lungs) - hydrocarbon with high aspiration potential - if pt is at risk of hemorrhage/ perforation

In the ER, what should be done?

- wash wound - remove remaining rings, constrictive clothing - start IV - lab work: coags, fibrinogen, platelets - tetanus vaccine - assess / grade envenomation - administer antivenom Do NOT give prophylatic abx, perform fasciotomy, excise tissue, give steroids.

What plants are convulsant toxins that can manipulate the GABA, Na channels or cause hypoglycemia?

- water hemlock - poison hemlock - looks like parsley - tobacco plant NO ANTIDOTE

What is the cocaine intoxication treatment?

1. Benzo until not fighting restraints (short acting) 2. Diltiazem: coronary artery vasodilation, opens up constricted vessels AVOID BETA BLOCKERS

Whole Bowel Irrigation is an osmotically balanced solution that is currently recommended for: 1. _____ 2. _____ 3. ______

1. sustained release or enteric coated preparations 2. solid iron preparations 3. foreign bodies (batteries, baggies of drugs)

What APAP level is concerning for toxicity?

4 hour APAP level of >150 mcg/mL

What is the initial dosing of Crofab?

4-12 vials or until initial control (stop progression of systemic symptoms) Crofab covers many species.

Who gets snake bites more? Men or women?

73% men 27% women

What are the symptoms of acute radiation syndrome (ARS)?

ARS includes : - hematopoietic (1-2 Guy) - gastrointestinal (2-6 Gy) - neurological (6-8 Gy) - cutaneous (>3 Gy) can occur w/wo ARS

What is the mechanism of nerve agents ?

Acetylcholine esterase inhibition Get acetylcholine hyperstimulation to nicotinic and muscarinic receptors (secretions, muscle weakness/paralysis) Victims die of respiratory distress

Activated charcoal is a fine powdery substance with a large surface area. It absorbs many poisons but cannot absorb ________ (5 things).

Activated charcoal cannot absorb 1. alcohols 2. metals 3. hydrocarbons 4. corrosives 5. inorganics

What are the types of radiation and what can they penetrate?

Alpha: stopped by paper, clothes Beta: stopped after few mm of tissue X-ray/gamma: very penetrating Neutron: very penetrating

Hot as a hare Red as a beet Blind as a bat Dry as a bone Mad as a hatter Fast as a cat (HR) Full as a tick What drug class causes symptoms mentioned above?

Anticholinergics Hot - peripheral vasodilation = feverish Red - vasodialtion = flushing skin Blind - mydriasis (dilated pupils) Dry - dry up secretion Mad - hallucinations Fast - tachycardia Full - urinary retention

Mees-Aldrich lines are nail bed lines found in people with ________ exposure.

Arsenic They may also have hyperpigmented skin

Antidote for Organophosphates

Atropine, Pralidoxime

What drugs are used in organophosphate poisoning ?

Atropine: muscarinic sx (secretions) Pralidoxime: nicotinic sx (muscle fasciculations, weakness, miosis)

A drunk guy was sleeping under his house near some chaotic, irregular, drunk-looking spider webs. He felt a pinprick sensation on his arm just as the sun rose. Within 1-2 hours he began feeling sweaty, tachcardic, and hypertensive and had muscle cramping in his arm, shoulder and chest. What bit him?

Black widow spider Most envenomations managed with opioids, benzos, and antivenin for severe cases.

What is the oral dose of N-acetylecysteine ?

Bolus: 140mg/kg x 1 Maintenance: 70mg/kg every 4 hours x 17 doses

What is the IV dose of N-acetylecysteine ?

Bolus: 150mg/kg x 1 (over 1hr) Maintenance: 50mg/kg x 1 (over 4 hours) then.... 100mg/kg x 1 (over 16 hours) (volume of administration depends on age)

A drunk guy was sleeping in his attack in Louisiana and now comes to the ER with an ischemic insect bite that has a erythematous halo-effect. While waiting in the ER for a long time, a dark eschar forms. He said he did not notice anything while he slept, but it started "hurting like hell" a few hours after waking up. What bit him?

Brown recluse Treat with wound care, abx if truly infected

What are the clinical forms of the plague?

Bubonic: regional lymphandenitis, 60% mortality Primary, secondary: 100% mortality Pneumonic: droplet transmission, 100% mortality

What are some major signs/ symptoms of TCA toxicity?

CNS depression, agitation, possibly seizure, coma, jerking (blocks fast Na channels) Anticholinergic effects (SLUDGE) Cardiac effects: sinus tachycardia, prolonged QRS > 100 sec

Diarrhea Urination Miosis Bronchorrhea / bronchospasm Emesis Lacrimation Salivation What drug class(es) causes symptoms mentioned above?

Cholinergics Nerve agents Insecticides Pilocarpine

Gastric Lavage is not routinely used because _____.

Clinical benefit not shown Markedly ineffective about 60 minutes after ingestions. Could consider in very recent ingestion of highly toxic substance

What is the difference between cocaine and anticholinergic overdose?

Cocaine intoxication patient will have sweating, anticholinergic patient will not.

What is the mechanism of atropine?

Competitive antagonist of acetylcholine at muscarinic receptors Treats muscarinic Dries secretions Increases heart rate

Lead screening may be yearly or monthly depending on the blood level. However, chelation is considered at level _____ and definitely started at level ____.

Consider chelation with succimer or CaNa2EDTA with level 45. Start chelation at level 70, patient will require hospitalization. Before that, it is education, drawing frequent levels and possibly investigating environment

What are the three forms of anthrax?

Cutaneous: most common, least mortality (20%) GI: bloody diarrhea, 50-100% mortality Inhalation: hemorrhagic mediastinitis, 100% mortality

What do you use to treat iron overdose?

Deferoxamine Note: HD does not remove iron

Antidote for Digoxin

Digibind, Digifab

Chelation therapy for arsenic includes ______ and _______.

Dimercaprol (BAL) Succimer (DMSA)

Which toxic alcohol causes: - CNS depression - metabolic acidosis - HTN, tachycardia - hyperventilation - oliguria, anuria - calcium oxalate crystals in urine - renal failure

Ethylene glycol

T/F: The FDA rigorously tests all herbal supplements for safety and efficacy.

FALSE!!!!! Safety and efficacy is the responsibility of the company (for what it's worth) and the FDA can step in after a product is brought to market. This is vastly different than Rx medications that must prove have safety and efficacy.

Antidote for benzodiazepines

Flumazenil

Antidote for Ethylene glycol, Methanol

Fomeprazole

How do you treat ethylene glycol toxicity?

Fomeprizole * Diethylene glycol presents and is treated similarly

Lead poisoning causes GI and CNS effects. Name some.

GI - anorexia - abdominal pain - vomiting - constipation CNS - irritability - learning disability - drowsiness - headache - ataxia - peripheral neuropathy

What are two common side effects of herbal products?

GI upset Platelet / coagulation interactions

How do you diagnose cyanide toxicity?

History of exposure (? Almond smell) Rapid onset of symptoms Cherry red skin Respiratory distress Acidemia (incr lactate)

What is the treatment for cyanide toxicity?

Hydroxocobalamin Rapidly improves HR, BP, acidemia

Antidote for cyanide

Hydroxycobalamin

____________ are responsible for more deaths in the US than from any other envenomation.

Hymenoptera (bees, wasp, ants)

MSDS contains what information?

Information on: - safe storage and handling - emergency actions - health effects information

Which toxic alcohol causes: - CNS depression - Ketonemia - Fruity breath - N/V, possibly hemorrhagic gastritis

Isopropyl alcohol

What are the components of Crotalinae snake venom?

Local tissue damage: metalloproteinase, phospholipase A2, hyaluronidase Coagulation effects: metalloproteinase, phospholipase A2, serine proteinases, C-type lectin-like proteins Platelet effects: disintegrins, metalloproteinase, phospholipase A2, C-type lectin-like proteins Neurotoxic effects: phospholipase A2

Which toxic alcohol causes: - sedation, ataxia, possibly seizures and coma - blindness by destroyin optic disk - N/V, abd pain

Methanol

What are the mild, moderate and severe toxic ranges for aspirin toxicity?

Mild = 150 mg/kg Moderate = 150-300 mg/kg Severe = > 300 mg/kg

Briefly describe the three grades of envenomation.

Minimal: swelling at area of bite at 30-60 mins, NO parathesis, fasciculations, blebs, or ecchymosis. NO abnormal labs Moderate: swelling, progessive, enlarging at 90 mins. Mild cyanosis, ecchymosis. Periorbital paresthesis. MINIMAL laboratory abnormalities. Severe: SYSTEMIC signs and symptoms. MARKED laboratory abnormalities. Rapid progression of local findings and progressive despite treatment.

What are centrally acting toxic inhalants?

Mustard HCl Ammonia Centrally acting bc high lipid solubility and cross BBB easily

Antidote for Acetaminophen

N-acetylcysteine

What is the antidote for APAP toxicity?

N-acetylecysteine (NAC) "Acetedote"

What is the toxic metabolite in APAP overdose?

NAPQI - covalently bonds to hepatic cells --> damage to centrilobular area --> AST, ALTs in the 1000s!!!!

Antidote for opiates

Naloxone (Narcan)

Is anthrax person-to-person transmission?

No!! Must come in contact with infected animal or contaminated products. (spores)

What are the cocaine metabolites?

Norcocaine: 5%, active metabolite Benzoylecgonine: 20-25%, ON THE UDS, KNOW THIS ONE!!!! no other way to get this in UDS Ecgonine Methyl Ester: 30-50% Coca Ethylene: active metabolite

What is the mechanism of organophosphate poisoning ?

Organophosphates complexes and deactivates acetylcholinesterase enzymes (Ach does not degrade) Interferes with muscarinic and nicotinic synapses

Briefly describe phases of acute iron toxicity.

Phase 1: first 6hr, N/V/D, abd pain, melena Phase 2: 6-24hr, resolving GI s/sx, lethargy, tachycardia Phase 3: 12-24hr, shock phase - hypotension, vasodilation, poor cardiac output Phase 4: 2-3 days post ingestion, hepatic failure Phase 5: 2-8 weeks post ingestion, scarring / fibrosis

What are peripherally acting toxic inhalants?

Phosgene (smell like grass) Nitric oxide PFIB (perfluorisobutylene) HC Low lipid solubility so remain peripherally

Plant based GI toxins that cause prolonged N/V include:

Pokeweed Solanaceous alkaloids that are in green potates

What diagnostic studies may help confirm organophosphate toxicity?

RBC cholinesterase: preferred, more indicative of body stores and clinical outcome but difficult to obtain; need baseline Plasma cholinesterase: quicker turn around but less reliable and less predictive

Syrup of Ipecac is a 5HT3 agonist that induces vomiting. It was once available OTC but has been largely removed from shelves because _____. What is the major adverse effect long term?

Removed due to abuse potential (bulemics) Chronic use causes cardiomyopathy

What is the mechanism of pralidoxime (2-PAM)?

Reverses phosphylation of cholinesterase enzyme Treats nicotinic symptoms Improves muscle weakness/paralysis

What agents case Anion Gap Metabolic Acidosis?

Salicylates Lactic acidosis Uremia Methanol Paraldehyde Ethylene glycol Diabetic ketoacidosis

What should you give for TCA toxicity and why?

Sodium Bicarbonate - IVF or bolus Increases pH of blood, which increases protein binding of TCA thus less free TCA Also can give 3% NaCl as fast sodium channels are blocked by TCA Norepi for hypotension

What is the most destructive enzyme in the brown recluse venom?

Sphingomyelinase D

Vesicants such as _______ and _______ cause skin blistering.

Sulfur mustard Lewisite

T/F: The Mojave rattlesnake may have a bite that produces delayed symptoms and require longer observation.

True

T/F: Organophosphate poisoning presents with cholinergic toxicity.

True Diarrhea Urination Miosis (pinpoint pupils) & Muscle fasciculations Bronchorrhea / bronchospasm Emesis Lacrimation Salivation

T/F: Homeopathic supplements rely on dilution factors to deliver activated products

True - probably all just water

T/F: Humans are the only reservoir for smallpox which spreads person-to-person via aerosolized droplets and direct contact.

True. Eradicated 1980 globally.

T/F: copperhead venom is not very toxic

True: copperhead venom usually does not produce a systemic response

T/F: Most snakebites occur between April and September.

True: most in July

Antidote for Isoniazid

Vitamin B6 (Pyridoxine)