Toxidromes Part II Flashcards
What is the mechanism of action of beta blockers?
Negative inotropy and chronotropy
What are the options in the management of a beta blocker overdose?
Atropine, Pacing, Glucagon
What is the mechanism of action of atropine?
It is the father of all anticholinergics –> causes increased HR
What is the mechanism of glucagon in the management of a beta blocker overdose?
Increased inotropy without competing with beta receptors
What are the most commonly ingested hydrocarbons?
Group 1 (greases, ex) and 2 (kerosene, gasoline, exs)
What is the greatest risk in the ingestion of a group 1 or 2 hydrocarbon?
Aspiration –> generally harmless if they stay in the GI tract
How is a patient treated after ingestion of a group 1 or 2 hydrocarbon?
Observation only unless there is a risk of aspiration –> burping, vomiting, etc.
What are examples of group 3 and 4 hydrocarbons?
3: benzene
4: carbon tetrachloride
What is the risk associated with group 3 or 4 hydrocarbon ingestion?
Chronic use leads to cancer from DNA mutation
What type of person is commonly exposed to carbon tetrachloride?
Dry-cleaners
What is the greatest risk associated with a PCP ingestion/overdose?
Violent behavior –> induces hallucinations and delusions that may cause them to harm themselves
What is done to manage a PCP ingestion/overdose?
Place them in a holding room with nothing they can use to harm themselves
May administer haloperidol or a benzo for sedation
What is the difference between organophosphates used as a pesticide compared to those used in a nerve gas?
The only difference is dose –> the mechanism is the same
What is the mechanism of action of organophosphates?
Irreversible inhibitors of acetylcholinesterase resulting in acetylcholine overload
What are the symptoms associated with toxic exposure to organophosphates?
S: salivation L: lacrimation U: urination D: defecation G: GI overload E: excretion Also bradycardia, miosis, and respiratory depression
True/False: There are pharmacological uses for reversible acetylcholinesterase inhibitors.
True –> most end in “stigmine”
What type of people present with organophosphate toxicity?
Intentional exposures
Farmers exposed to pesticides
Military personnel exposed to chemical warfare
How is organophosphate toxicity managed?
Remove all clothing/jewelry and decontaminate the skin with copious amounts of water
Administer atropine
Administer 2-PAM (Pralidoxime)
To decontaminate a patient exposed to organophosphates, would you use cold or warm water?
Cold water –> warm water is going to increase the rate of absorption
What is the mechanism of action of 2-PAM (pralidoxime)
Kicks the organophosphate off the acetylcholinesterase enzyme so that it can break down acetylcholine
When should 2-PAM (pralidoxime) be administered in organophosphate toxicity?
ASAP –> the longer after exposure 2-PAM is administered, the less effective it will be
What is the mechanism of action of barbiturates?
Agonize GABA –> an inhibitory neurotransmitter
What other drug class are barbiturates similar to and what is the key difference between the classes?
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.
What is the schedule drug class of barbiturates and benzos?
Barbiturates: C-3
Benzos: C-4
What are the signs and symptoms of barbiturate toxicity?
Respiratory depression, hypotension –> overload of inhibitory neurotransmission
T/F: Barbiturates are commonly used for suicide and euthanasia.
True –> barbiturates elicit a “pleasant death”
When choosing a barbiturate for euthanasia/suicide, should you use a long-acting or short-acting barbiturate and why?
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.
What is the treatment of toxicity for most barbiturates?
Management of symptoms / supportive care
For which barbiturate is there a specific treatment for toxicity and how does it work?
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.
What might a patient complain of to get a provider to prescribe a short acting barbiturate?
Sleep disorders refractory to more common treatments –> melatonin, ambien, benadryl, benzos, etc.
T/F: Barbiturates are good medications for pain control.
False: barbiturates and benzos have no analgesic properties.
