Pharmacology of Poisoning: Toxidromes

Question 1

What are the two drugs associated with Serotonin Syndrome?

Answer 1

Meperidine (if given with MAO inhibitor) and Linezolid (given with SSRI)

• MAOIs SSRIs, anything that increases Serotonin

Question 2

After taking a certain drug, the patient develops diaphoresis, diarrhea, ataxia, confusion, and especially clonus and rigidity as well as tremor. What is she diagnosed with?

Answer 2

Serotonin Syndrome

Question 3

What are the treatments for Serotonin Syndrome?

Answer 3

Cyproheptadine - Serotonin blocker (KEY)

Lorazepam - Benzo (if Mild sx.)

Rocuronium - for muscle paralysis and intubation (non-depolarizing muscular blockers)

Question 4

Neuroleptic Malignant Syndrome: Cause, Sx, and Tx.

Answer 4

Cause: Typical antipsychotics (dopamine antagonist)

Sx: Muscle rigidity

Tx: Dantrium (aka Dantrolene) = Key Drug (muscle relaxer) + Bromocriptine + Rucornium, Lorazepam (same drugs)
- Not mentioned in pharmorveriew

Question 5

Malignant Hyperthermia: Cause, Sx, and Tx

Answer 5

Cause: Genetic Instability of the sarcoplasmic reticulum + inhaled anesthetics (Nitrous Oxide and Sevoflurane)

Sx: Muscle rigidity, Tachycardia, Hyperkalemia

Tx: Dantrolene = interfering with/inhibiting the release of Ca2+ from sarcoplasmic reticulum

Question 6

Anticholinergic: Cause, Sx and Tx.

Answer 6

Cause: Anticholinergic or TCAs

Sx: Mad as a hatter, red as a beet, blind as a bat, hot as a hare, and dry as a bone.

Tx: Physostigmine: AChE Inhibitor

Question 7

Cholinergic: Cause, Sx, and Tx

Answer 7

Cause: Organophosphate Poisoning (Malathion, Parathion)
- Increases Ach by inactivating AChE

Sx: DUMBBELSS (Lacrimation, salivation, sweating, Miosis, Brady Cardia, Diarrhea, etc.)

Tx: Atropine (blocks M receptor) and Pralidoxime (regenerates AchE)
- For nerve gas: Combine both (DuoDote)

Question 8

Opioid Tx:

Answer 8

Naloxone

Question 9

Acetaminophen Overdose: Cause, Sx/Adverse Effect to watch out for, and Tx

Answer 9

Cause: Too much tylenol at once (acute) or over a period of time (chronic)

Sx/Adverse Effect: Hepatotoxicity

Tx: Acetylcestine = restores glutathione levels

Question 10

What is the MOA of Acetylcysetine and what is it used for?

Answer 10

Used for Acetaminophen overdose

• Restores glutathione levels so that the toxic intermediate (NAPQI) can be conjugated and detoxified.
• Acetaminophen usually undergoes sulfate conjugation (CYP system) and forms NAPQI

Question 11

Ethylene Gylcol and Methanol Poisoning: Sx and Tx

Answer 11

Sx: Metabolic Acidosis for both +

• Ethylene Glycol: Renal tubular damage
• Methanol Poisoning: Ocular damage + blindess

TX: Fomepizole: competitive inhibitor of alcohol dehydrogenase

Question 12

Cyanide Poisoning: Cause, Sx, and Tx

Answer 12

Cause - insecticides, smoke inhalation, etc.

Sx: Smell of bitter almonds

Tx:
- Cyanide Kit: amyl and sodium nitrite, sodium thiosulfate. Order is important.

OR

• Hydroxocobalamin: Combines with Cyanide to make CYANOCOBALAMIN (Vit B12)