Toxicology Flashcards
(60 cards)
1
Q
toxicology referrs to
A
the detection, effects, properties and regulation of toxic substances
2
Q
Determinants of toxicity?
A
DOSE and DURATION OF EXPOSURE (blood plasma levels)
3
Q
Father of modern toxicology?
A
paracelsus
4
Q
Therapeutic index eqn:
A
TI=LD_50/ED_50
5
Q
Safer drug has what therapeutic index=
A
larger TI number
6
Q
ALD-Average lethal dose is determined from?
A
estimated from accidental deaths in humans
7
Q
What is the primary determinant of toxicity?
A
dose
8
Q
Clinical management of poisoning:
A
- Support vital - ACB
- Rule out other differentials- IDENTIFY THE POISON (URINE,BLOOD,GASTRIC CONTENTS)
- Reduce, remove the drug in, from the body (decrease dose or decrease time of exposure)
9
Q
Clinical management of poisoning - unconscious patient:
A
- give general antidotes available (insulin/glucose if diabetic shock or hypoglycemic; naloxone for narcotic OD)
- use other drugs to treat seizures, cardiac arrhythmias, and severe agitation
10
Q
toxidromes: what are they? how related to patient?
A
TOXILOGIC FINGERPRINT FOR AN OD OR POISONING
known toxicology standards of known adverse events - so comparison of the drug or chemical response of the patient with the known tox standard
11
Q
Lab tests that can be performed in less than 2 hours:
A
Urine-immunoassay and TLC
Urine/Blood-HPLC or GCMS
12
Q
Drug removal via emesis- what to give?
Contraindication
A
- mechanic - a finger bro
- apomorphine
- syrup of Ipecac
- petroleum hydrocarbon solvent poisoning-chemical pneumonitis
- caustic acid of alkali agent= rupture
- seizing or comatose patient
13
Q
Gastric lavage is?
A
stomach pumping
14
Q
Activated charcoal
- how administered
- how work/
- what for?
A
- orally in water
- very large surface area allows for binding of organic toxicants = no absorption
- othen induces vomoting too
15
Q
Cathartics
- what does it do?
- exs?
A
- promotes rapid movement and elimination of poison through GI tract
- sorbitol, mag citrate, mag sulfate
16
Q
When to dose activated charcoal?
A
-for max effect within 30 min of poison ingestion
17
Q
activated charcoal-interactions:-
A
effectiveness of other meds decreases with co-administration
18
Q
for organophos poisoning and want to use a chelator give? give with what other drug?
A
pralidoxime - give with atropine to block muscarinic effects of PNS
19
Q
for cyanide poisoning and want o give celator?
MOA?
A
amyl nitrate, sodium nitrate, and sodium thiosulfate with O2
(Hb forms methemoglobin = methemoglobin+CN= nontoxic
20
Q
farmer poisoning give?
A
pralidoxine + atropine (probably organophos poisoning from fertilizer)
21
Q
toxic dose of cyanide?
A
2mg/kg = death w/in 10-15 min
22
Q
Botulinum toxin - give what treatment?
-whats special about botulinum toxin?
A
- must treat ABCs, lavage, emesis, charcoal, trivalent antitoxin
- Most potent poison known - rapid absorption = prevent Ach release from nerve terminals = respiratory depression
23
Q
Heavy metal poisoning - give what?
A
- Chelators (BAL, EDTA, DMSA, DMPS,Ca-EDTA, deferoxamine)
- form complex with heavy metals = inert and renal excretion
24
Q
BAL is?
A
british anti-lewisite, dimercaptol - for heavy metal poisoning
25
Tx for lead poisoning?
DMSA, succimer - smells like shit drug - need to put in food or something
26
Dosage for children >=12 yo w/ lead poisoning,arsenic, or mercury poisoning?
DMSA, succimer-10mg/kg PO q8h for 5 days
27
Dosage for children 1-11 yo with lead,arsenic, or mercury poisoning?
DMSA, succimer-10mg/kg PO q8h for 5 days
- give same dose then for q12h for 14 days
- total of 19 day therapy
- put in food or juice
28
Trivalent antitoxin for botulism A,B,E
- where does it come from?
- how to get?
- indications?
- equine
- from CDC via state and local health departments
- good against botulinum toxins types A B and E -most common types we get
-Another heptavalent antitoxin is available against all types
29
Trivalent antitoxin for botulism A,B,E
| -Dosing:
- single 10ml vial per patient - slow IV infusion
| - this antitoxin contains WAYYY mORREE antibodies for the toxin than you probably have in your body so itll be enough
30
Cyanide antidote
| -administration:
- its an antidote kit
1) small inhaled dose of amyl nitrite
2) IV sodium nitrite - oxydize portion of Hb iron from ferrous to ferric state = Hb to methemoglobin
3) sodium thiosulfate - reacts with cyanmethemoglobin to give thiocyanate (and sulfate) + Hb --> thiocyanate is peed out
31
Treat methanol, ethylene glycol, isopropyl alcohol poisoning?
- Give ehtanol bc it prevents *alcohol dehydrogenase* from converting bad substances into even more toxic substances that kill you
- can give FOMEPIZOL - inh alcohol dehydrogenase
-can use hemodialysis as adjunct therapy
32
Methanol in the body is converted into what by what enzyme?
-alcohol dehydrogenase - formaldehyde and formic acid
33
Fomepizol is for? MOA?
Treat methanol, ethylene glycol, isopropyl alcohol poisoning -
blocks alcohol dehydrogenase
34
Ethylene glycol in the body is converted into what by what enzyme?
What does the breakdown cause?
- alcohol dehydrogenase
- bunch of crap glycoadehyde... glycoate, glycolic acid, glyxylate
-renal failure
35
Tx for Ethylene glycol poisoning?
- ehtanol - competitive inh of alcohol dehydrogenase
- fomepizol - block alcohol dehydrogenase
- hemodialysis in symptomatic patints
36
Carbon monoxide poisoning
- how poison?
- tx?
- 210x greater affinity for Hb than O2 - binds strong = carboxyhemoglobin COHb
- artificial respiration with pure O2 to promote displacement of CO - hyperbaric chamber if symptomatic
37
Symptoms of CO poisoning - 0-10% COHb=
NONE
38
Symptoms of CO poisoning - 20-30% COHb=
slight headache
| exertional dyspnea
39
Symptoms of CO poisoning - 30-40% COHb=
throbbing headache
fatigue
dizziness
SOB
40
Symptoms of CO poisoning - 40-60% COHb=
-severe headahce
-weakness
-dizziness
-confusion
-dimness of vision
(CHERRY RED APPEARANCE)***
41
Symptoms of CO poisoning - >60% COHb=
convulsions
coma
respiratory collapse
DEATH bro
42
Warfarin -
- what for?
- adverse symptoms:
- anticoag interferes wtih synthesis coag factors 2, 7,9, 10 c and s (VIT K dependent factors)
- hemoptysis, excessive bruising, bleeding from nose or gums, blood in urine or stool
43
Overdose of warfarin give?
- receptor competitor therapy
- injection of vitamin K (phytonadione)
- if severe bleeding give pro-thrombin complex or fresh frozen plasma to replace coag factors
44
Opiates -
- name classes
- what tx? benefit to each?
- heroin, morphine, meperidine...
- receptor competitor theory
1) Naloxone: act at mu, kappa, and delta recptors = block reverse effects- duration of action = 45min
- used to save acute OD life
2) Naltrexone:
- act at same receptors
- longer duration (24-72 hrs)
- used for withdrawal symptoms in rehab
45
Methemoglobinemia
- issue with this state?
- how caused?
- tx & MOA?
- cant transport O2 (Ferric=ok, ferrous= not good)
- caused by exposure to various chemicals (nitrites sulfa, drugs, and many others
- Methylene blue- direct chemical reduction of methemoglobin back to hemoglobin
46
Sympatheticomimetic toxidrome
- what drugs?
- what do you see?
- cocaine, amphets, PCP
- mydriasis (DIALYSIS)
- HTN
- tremor
- hyperthermia
- CNS= hallucination agitation, paranoia
47
Sedative/hypnotic toxidrome
- what drugs
- what do you see?
- ETOH, barbs, benzos
- coma
- Decrease respiration
- miosis or mydriasis
- hypotension
48
Opioid Toxidrome
- what drugs?
- what do you see?
- opiates, morphine, codine, propoxyphene, oxycodone, hydrocodone
- CNS - coma or dec consciousness
- respiratory depression
- MIOSIS (PINPOINT)
- opiad triad (hypothermia, hypotension, histamine release)
49
Anticholinergic toxidrome
- what drugs?
- what do you see?
- anticholinergics and antidepressants
- agitation
- mydriasis
- FEVER, DRY SKIN, FLUSHING, URINARY RETENTION (HOT,DRY, MAD, RED, BLIND)
50
Cholergic toxidrome
- what drugs?
- what do you see?
- organophosphatese/carbamates and insectisides, nicotine
- miosis (PINPOINT)
- DUMBBELLS (EVERYTHING WET)
51
tricyclic antidepressant toxidrome
- what drugs?
- what do you see?
- TCAs (amytriptyline, imipramine, desipramine)
- coma, agitation
- mydriasis
- dysrhthmias
- convulsions, hypotension (alpha block)
52
Salicylate toxidrome
- what drugs?
- what do you see?
- aspirin
- inc or normal RR
- diaphoresis aka sweaty
- tinnitis
- agitation
- alkalosis (early)
- acidosis (late)
- hyperpyrexia
53
Acid poisoning characteristics
- immediate pain in buccal cavity and esophagus
- less often swallowed than bases
- no esophageal perforation
54
Base poisoning characteristics
- primary cause of chemical burns
- rapidly penetrating liquefactive necrosis
- primary effects on esophagus and only 20% on stomach
- esophageal damage including perforation
55
Meperidine OD characteristics:
- mydriasis due to antimuscarinic
| - INC IN HR
56
Opiates OD chacteristics:
- bilateral miosis
| - HR and RR depression/arrest
57
Benzos OD characteristics:
| TX?
-rarely fatal unless taken with ETOH or other CNS depressants
give flumazenil!!
58
Acetaminophen OD characteristics
| -TX?
- after depletion of glutathione (important for phase 2 metabolism)= hepatic necrosis and death due to hepatic failure
- give n-acetylcysteine!
59
Cocaine OD characteristics
| -tx?
- cardiac dysrhythmias -->cardiac arrest
| - give lidocaine for dysrhythmias but noantidote
60
dioxin
| -signs of exposure?
cloaracne - small yellow comedones on face
