1. Fundamental Concepts & Definitions

Poison: Any substance that produces harm or even death to a living organism.
- Lecturer's Emphasis: The word "any" is critical for the definition and points will be deducted if it's missing.
Clinical Toxicology: The specific pathology caused by poisons and the management of that pathology.
Types of Drug Doses (Lecturer's List):
1. Loading Dose
2. Sub-Clinical / Sub-Therapeutic Dose
3. Therapeutic Dose
4. Overdose
5. Toxic Dose
6. Lethal Dose (The dose that causes death)
Classification of Poisoning:
- According to their nature (Solid, Liquid, Gas)
- According to their mode of action (Local, Remote, Double)
- According to their target organs
Factors Affecting the Toxic Response

2. Diagnosis of Poisoning

How to Suspect a Toxicological Case

The lecturer highlighted 3 main signs of suspicion (from Slide 8):

Toxidromes (Key Syndromes)

Definition: A specific syndrome (collection of signs) caused by a specific toxin.
Cholinergic Toxidrome:
- Mnemonics (Slide 11):
- - DUMBELS: Diarrhea, Urination, Miosis, Bradycardia/Bronchospasm, Emesis, Lacrimation, Salivation/Sweating
  - SLUDGE: Salivation, Lacrimation, Urination, Defecation, GI upset, Emesis
- Antidote (Slide 12):
- - Atropine: For muscarinic effects.
  - Pralidoxime: Reverses cholinesterase phosphorylation.
Anticholinergic Toxidrome:
- Classic Mnemonic (Slide 14):
- - "Dry as a bone" (Dry mucous membranes)
  - "Mad as a hatter" (Mental status changes)
  - "Red as a beet" (Flushed skin)
  - "Blind as a bat" (Mydriasis - dilated pupils)
  - "Hot as a hare" (Fever)
Clinical Pearl: Differentiating Toxidromes (Slide 15)
- Sympathomimetic vs. Anticholinergic: Both can cause tachycardia, hypertension, and mydriasis.
- The Key Difference: Sweating.
- - Sympathomimetic patients are typically sweaty.
  - Anticholinergic patients are dry ("Dry as a bone").

Investigations

Toxicological Screening (Slide 31): The simple, essential "spot test" done on urine, often with a dipstick, to look for color changes.
Signs of Lateralization (Slide 30): Neurological signs indicating a focal issue.
- Unequal pupils
- Deviation of the eyes to one side
- Tilting of the head
- Facial asymmetry
Swallowed Radio-Opaque Object (e.g., coin, battery): The appropriate initial investigation is an X-ray to determine its location.

3. General Management of the Poisoned Patient

A-B-C-D Approach

"D" = Drugs (The "Coma Cocktail")
- Lecturer's Emphasis: This must be memorized ("like your name"). It is given empirically to any patient with an undiagnosed coma.
- 1. Glucose (50%): To correct hypoglycemia.
- 2. Thiamine (100mg): To correct/prevent Wernicke's encephalopathy (given before glucose if alcoholism is suspected).
- 3. Naloxone (0.4-2mg): To reverse opiate overdose.
Flumazenil (Benzodiazepine Antagonist) - A CRITICAL WARNING
- DO NOT give Flumazenil routinely to an undiagnosed coma patient.
- Reason (Slide 93): If the patient has a mixed overdose (e.g., with Tricyclic Antidepressants), reversing the benzodiazepines can unleash a fatal-arrhythmia or seizure.

"Elimination" vs. "Enhanced Elimination" (Lecturer's Concept)

1. Elimination (GIT Decontamination): Removing the poison from the GIT.
2. Enhanced Elimination: Removing the poison after it has been absorbed into the blood.

1. Elimination (GIT) Methods

A. Emesis (Inducing Vomiting)

Contraindications (Slides 52-53):
- Substance: Corrosives (acid/alkali), Hydrocarbons (risk of aspiration), Convulsants (can trigger a seizure).
- Patient: Unconscious, comatose, or decreased gag reflex.
CRITICAL WARNING (Slide 54): NEVER use salty water to induce emesis. It can cause fatal hypernatremia (high sodium).

B. Gastric Lavage (Stomach Pumping)

Time Factor: Generally ineffective >2 hours after ingestion.
Exceptions (Delayed Lavage IS useful for):
- Poisons with delayed gastric emptying (e.g., TCAs, Atropine)
- Poisons that form concretions/bezoars (e.g., Salicylates)
- Poisons eliminated back into the GIT (e.g., Opiates)

C. Activated Charcoal (AC)

Dose (Slide 66):
- Unknown amount: 1 gm/kg of body weight.
- Known amount: 5-10 times the weight of the ingested poison.
NOT Effective For (Slide 64):
- Iron
- Alcohols
- Cyanide
- Lead & Mercury (Heavy Metals)

D. Dilution / Neutralization

For Strong Acid Ingestion: Give a buffering agent like milk.
CRITICAL WARNING: NEVER give a strong alkali to "neutralize" a strong acid (or vice versa). This causes an exothermic (heat) reaction and can perforate the stomach.

2. Enhanced Elimination (Blood) Methods

Guiding Principle: Choose the method that is easier, simpler, cheaper, and effective (الأسهل، الأيسر، الأرخص، الفعال).
Forced Diuresis (Urination):
- This is the simplest initial method.
- Just giving water is not enough.
- Uses osmotic diuretics like Mannitol (Slide 70).
Dialysis:
- General Definition (Slide 73): Allowing blood to contact a semi-permeable membrane to remove substances via a concentration gradient (not just "kidney dialysis").
- Primary Indication for Hemodialysis (Slide 73): Used when the patient's kidney function is already impaired (e.g., they have renal failure).
- Contraindication: Ineffective for large molecules or highly protein-bound toxins (like heavy metals).

Lectures