Toxidromes Part II

Question 1

What is the mechanism of action of beta blockers?

Answer 1

Negative inotropy and chronotropy

Question 2

What are the options in the management of a beta blocker overdose?

Answer 2

Atropine, Pacing, Glucagon

Question 3

What is the mechanism of action of atropine?

Answer 3

It is the father of all anticholinergics –> causes increased HR

Question 4

What is the mechanism of glucagon in the management of a beta blocker overdose?

Answer 4

Increased inotropy without competing with beta receptors

Question 5

What are the most commonly ingested hydrocarbons?

Answer 5

Group 1 (greases, ex) and 2 (kerosene, gasoline, exs)

Question 6

What is the greatest risk in the ingestion of a group 1 or 2 hydrocarbon?

Answer 6

Aspiration –> generally harmless if they stay in the GI tract

Question 7

How is a patient treated after ingestion of a group 1 or 2 hydrocarbon?

Answer 7

Observation only unless there is a risk of aspiration –> burping, vomiting, etc.

Question 8

What are examples of group 3 and 4 hydrocarbons?

Answer 8

3: benzene
4: carbon tetrachloride

Question 9

What is the risk associated with group 3 or 4 hydrocarbon ingestion?

Answer 9

Chronic use leads to cancer from DNA mutation

Question 10

What type of person is commonly exposed to carbon tetrachloride?

Answer 10

Dry-cleaners

Question 11

What is the greatest risk associated with a PCP ingestion/overdose?

Answer 11

Violent behavior –> induces hallucinations and delusions that may cause them to harm themselves

Question 12

What is done to manage a PCP ingestion/overdose?

Answer 12

Place them in a holding room with nothing they can use to harm themselves
May administer haloperidol or a benzo for sedation

Question 13

What is the difference between organophosphates used as a pesticide compared to those used in a nerve gas?

Answer 13

The only difference is dose –> the mechanism is the same

Question 14

What is the mechanism of action of organophosphates?

Answer 14

Irreversible inhibitors of acetylcholinesterase resulting in acetylcholine overload

Question 15

What are the symptoms associated with toxic exposure to organophosphates?

Answer 15

S: salivation
L: lacrimation
U: urination
D: defecation
G: GI overload
E: excretion
Also bradycardia, miosis, and respiratory depression

Question 16

True/False: There are pharmacological uses for reversible acetylcholinesterase inhibitors.

Answer 16

True –> most end in “stigmine”

Question 17

What type of people present with organophosphate toxicity?

Answer 17

Intentional exposures
Farmers exposed to pesticides
Military personnel exposed to chemical warfare

Question 18

How is organophosphate toxicity managed?

Answer 18

Remove all clothing/jewelry and decontaminate the skin with copious amounts of water
Administer atropine
Administer 2-PAM (Pralidoxime)

Question 19

To decontaminate a patient exposed to organophosphates, would you use cold or warm water?

Answer 19

Cold water –> warm water is going to increase the rate of absorption

Question 20

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

Answer 20

Kicks the organophosphate off the acetylcholinesterase enzyme so that it can break down acetylcholine

Question 21

When should 2-PAM (pralidoxime) be administered in organophosphate toxicity?

Answer 21

ASAP –> the longer after exposure 2-PAM is administered, the less effective it will be

Question 22

What is the mechanism of action of barbiturates?

Answer 22

Agonize GABA –> an inhibitory neurotransmitter

Question 23

What other drug class are barbiturates similar to and what is the key difference between the classes?

Answer 23

Similar to benzos, but benzos require GABA be present to exert their effect. Barbiturates can mimic GABA so they will exert their effects even in the absence of GABA.

Question 24

What is the schedule drug class of barbiturates and benzos?

Answer 24

Barbiturates: C-3
Benzos: C-4

Question 25

What are the signs and symptoms of barbiturate toxicity?

Answer 25

Respiratory depression, hypotension --> overload of inhibitory neurotransmission

Question 26

T/F: Barbiturates are commonly used for suicide and euthanasia.

Answer 26

True --> barbiturates elicit a "pleasant death"

Question 27

When choosing a barbiturate for euthanasia/suicide, should you use a long-acting or short-acting barbiturate and why?

Answer 27

Short-acting because even though they are more easily reversible, the produce a more rapid death --> less likely to be discovered after ingestion before death occurs.

Question 28

What is the treatment of toxicity for most barbiturates?

Answer 28

Management of symptoms / supportive care

Question 29

For which barbiturate is there a specific treatment for toxicity and how does it work?

Answer 29

Alkalinize the urine for phenobarbital toxicity. Phenobarbital is an acidic drug. Administering a base will cause the drug to be more hydrophilic and be more easily excreted by the kidneys.

Question 30

What might a patient complain of to get a provider to prescribe a short acting barbiturate?

Answer 30

Sleep disorders refractory to more common treatments --> melatonin, ambien, benadryl, benzos, etc.

Question 31

T/F: Barbiturates are good medications for pain control.

Answer 31

False: barbiturates and benzos have no analgesic properties.