Toxicology

Question 1

What is a poison?

Answer 1

A substance that is physiologically harmful when admin. to a living organism

Question 2

What is the relationship of duration of exposure and dose with toxicity?

Answer 2

There is a positive relationship of both principles with toxicity

Question 3

What is the LD50?

Answer 3

The lethal dose at which 50% of animals tested die

-legally a poison

Question 4

What is the TI (Theraputic index)?

Answer 4

LD50/ED50

The larger the number, the safer the drug

Question 5

What is the TI of Benzos vs Barbiturates?

Answer 5

Benzos have a high TI and Barbiturates have a low TI

Question 6

What is the ALD

Answer 6

Average lethal dose

Question 7

What should be asked in Primary care if poisoning has occurred?

Answer 7

What was the dose? How much?

How long ago did they ingest it?

Question 8

What is the clinical management of poisoning?

Answer 8

Support vitals (ABCs)
Reduce/Remove the drug from the body

Question 9

What is unique about treating an unconcious patient?

Answer 9

General antidotes
-glucose/insulin(Diabetic shock/hypoglycemia)
-naloxone(narcotic OD)
Tx emergent conditions
ID the Poison

Question 10

What is the procedure to induce emesis?

Answer 10

Mechanical
Apomorphine
Syrup of Ipecac

Question 11

What are the contraindications of inducing emesis?

Answer 11

Petroleum hydrocarbon solvent (chemical pneumonitis)
Caustic acid or alkali agent
seizing or comatose Pt

Question 12

Why is activated charcoal a good option?

Answer 12

Admin orally in water

• very arge Surface area allows for binding of organic toxicants which prevents absorption
• often induces emesis

Question 13

What are cathartics?

Answer 13

Promotes rapid movement and elimination of poison through GI tract

Question 14

What are rhe antidotes that chelate Organophosphates?

Answer 14

Organophosphates

-Pralidoxime-Admin with Atropine to block antimuscarinic effects of PNS

Question 15

What are rhe antidotes that chelate Cyanide?

Answer 15

CNS and Cardiac tissue are esp affected
produce death in 1-15 min
Admin: Amyl nitrate, Na Nitrate, Na Thiosulfate with O2

Question 16

What are rhe antidotes that chelate Botulinum Toxin?

Answer 16

ABCs Trivalent anti-toxin, emesis, charcoal, lavage,

Question 17

What are rhe antidotes that chelate Heavy metals?

Answer 17

Chelators(BAL, EDTA, DMSA, DMPS, Ca EDTA) complex with Hg, Pb, As, Fe, Ag making them inert and increasing renal excretion.

Question 18

What is the Antidote DMSA?

Answer 18

Treats As, Hg(mercury), Pb(lead) poisoning
Dosage: Adults, PO for 5 days
Children, total of 19 days

Question 19

What is the Trivalent antitoxin for botulinum A, B, E

Answer 19

.

Question 20

What is the antidote for Cyanide?

Answer 20

Inhaled Amyl nitrate
IV Na Nitrite (reacts with Hb to form mHb)
IV Na Thiosulfate(reacts with mHb to give thiocyanate and hemoglobin

Question 21

What is the antidote for Alcohol(ethylene glycol, methanol, isopropylOH)

Answer 21

MethOH into Formaldehyde and formic acid by ADH

Hemodialysis as adjunct can be lifesaving withMethOH and ethylene glycol

Question 22

What is the action of Fomepizole

Answer 22

Blocks the Ez that converts EG ad MOH to toxic compounds***

Question 23

What is the Tx for CO poisoning?

Answer 23

Artificial resp. withpure O2 to promote displacement of CO, hyperbaric O2 if symptomatic

Question 24

What are the S and S of CO poisoning?

Answer 24

Cherry red lips and gums

Severe headache, weakness, dizziness

Question 25

What are the features of Warfarin overdose?

Answer 25

Hemoptysis, excessive, bruising, bleeding from nose, gums and urethra/anus
High INR

Question 26

Tx For warfarin OD?

Answer 26

Vit K

Question 27

What is the Tx of Opioid OD?

Answer 27

Naloxone- Fast acting (45 min)

Naltrexone- Long acting to maintan effect

Question 28

What is the Tx of Methemoglobinemia?

Answer 28

Cannot transport oxygen

Tx is Methylene Blue- Direct chemical reduction methemoglobin to hemoglobin

Question 29

What are Toxidromes?

Answer 29

Certain symptoms that are charicteristics of certain poisonous agents
Knowing the toxidromes can help you make fast decisions in emergent situations

Question 30

What are the sympathomimetic (CNS stimulants) toxodromes?

Answer 30

CNS-agitation, hallucinations, paranoia
Resp
pupils- Mydriasis(dilated pupils)
Other, HTN, Tremor, Hyperthermia, seizure
Drugs- Cocaine, Meth, PCP

Question 31

What are the sedative/hypnotic toxodromes?

Answer 31

CNS-coma
Resp- dec
pupils- miosis or mydriasis
Other, hypothermia
Drugs- alcohol, Barbiturates, Benzos

Question 32

What are the opioid toxodromes?

Answer 32

CNS-coma 
Resp-dec
pupils- pinpoint
Other, Opiate Triad:
Drugs- Opiates, morphine, codiene

Question 33

What are the anticholinergic toxodromes?

Answer 33

CNS-agitation
Resp-
pupils- dilation
Other, Fever, dry skin, flushing, urinary, retention
Drugs- anticholinergics, antidepressants

Question 34

What are the cholinergic toxodromes?

Answer 34

CNS-coma
Resp-
pupils- ppp
Other, SLUDE(fasiculation, incontinence, salivation, wheezing, lacrimation, bradycardia)
Drugs- organophosphates, nicotene, insecticides

Question 35

What are the tricyclic antidepressants toxodromes?

Answer 35

CNS-coma, agitation
Resp-
pupils- mydriais
Other, dysrhythmia, convulsions, hypotension(alpha blockade)
Drugs- TCA’s, amitriptiline, imipramine, desipramine

Question 36

What are the tricyclic antidepressants toxodromes?

Answer 36

CNS-up or down
Resp- increase or normal
pupils- 
Other, diaphoresis, tinnitis, agitation, alkalosis (ea), acidosis(lt), hyperpyrexia
Drugs- ASA, ASPIRIN, other salicylates