Midterm Pre & postlab (Antidotes) Flashcards
A processed charcoal that is obtained from the burning of carbonaceous substances. It involves extensive treatment w/ steam, CO2, O2, ZnCl, H2SO4, H3PO4, at 500-900°F that increases surface area.
A. Activated Charcoal
B. EDTA
C. N-acetylecysteine
D. Naloxone
A. Activated Charcoal
they are significantly bound?
Organic molecules
they are generally less well bound?
LMW & polar compounds
they are also not appreciably bound?
certain inorganic salts
this antidote has an adsorption at a ratio of approximately 10:1 and administered in1g/kg PO or gastric tube as aqueous suspension?
Activated charcoal
chelating agent especially for lead intoxication; hypercalcemia
Ethylenediaminetetraacetic acid (EDTA)
in chronic chronic Pb exposure, a medical condition characterized by high levels of calcium in the blood?
Hypercalcemia
the BLL that can be considered as Pb poisoning?
> 150mcg/dL
Dosing of EDTA for adult and children?
Adult: 2-4g or 30-50mg/kg
Children: 1000-1500mg/m2
IV q24H as continuous IV dil. 2-4mg/mL in NS or D5%
symptomatic: admin. for 3-5days
a precursor to glutathione, direct sulfhydryl binding agent; an antioxidant that helps neutralize the toxic metabolites of APAP that can damage the liver?
N-acetylcysteine (NAC)
Dosing of NAC:
140mg/kg LD dil. in juice or soda
MD: 70mg/kg q4H
competitive opioid antagonist; takes effect 1-2 mins. after IV. Used in opioid overdose
Naloxone
longer elimination t1/2 and DoA; discontinued in US. Used to treat alcohol dependence.
Nalmefene
active Po; prevent recidivism in patients detoxified after opioid abuse, and reduce alcohol craving.
Naltrexone
Dosing of Naloxone:
Adults: 0.4-2mg IV initially, repeat at 2-3 mins. interval; 0.4-0.8mg/h continuous IV (NS or D5%), titrate for effect.
Specific chelating agent for iron (free)
Deferoxamine
it is water soluble & renally excreted as (?)
Red ferrioxamine complex…orange-pink/vin rose
Dosing of Deferoxamine:
5 mg/kg/h IV increasing over 15 mins as tolerated,
do not exceed 15mg/kg/h
enzyme that converts a small portion of the drug into a toxic metabolite known as N-acetyl-p-benzoquinone imine (NAPQI).
P450 (CYP2E1)
product of the combination of glutathione to NAPQI to form nontoxic substance?
Cysteine & Mercapturic acid conjugates
Dosing of Paracetamol poisoning:
Children: >200mg/kg
Adults: 6-7g
Early manifestations of Paracetamol poisoning
anorexia & NV
After 24-48 hrs. manifestations of Paracetamol poisoning
AST & ALT levels rise; evident hepatic necrosis
Paracetamol poisoning is diagnosed by?
Nomogram; electrolytes (anion gap), liver enzymes
a tool used to assess the risk of liver damage following paracetamol overdose.
Rummack-Matthew nomogram
chemical asphyxiant binds to these to block the aerobic utilization of oxygen?
cellular cytochrome oxidase
a much less toxic compound that is excreted in the urine?
Thiocyanate
level of Hydrogen cyanide to be considered as cyanide poisoning:
150-200ppm
level of ingested Na or K salts to be considered as cyanide poisoning:
200mg
Antidote for Cyanide poisoning
Hydrocobalamin
Nithiodote
Universal antidote is composed of:
2 parts AC
1 part TA
1 part MgO
forms a protective film relieving inflammation and irritation
Demulcent
Examples of demulcent:
Milk
egg albumin (egg white)
this prevents absorption by binding with heavy metals
Demulcent
Cyanide poisoning is diagnosed by:
lactic acidosis
elevatad venous O2 saturation
“bitter” almond odor
Abrupt onset of profound toxic effects present in cyanide poisoning shortly after exposure:
Headache
Nausea
Dyspnea (SOB)
Confusion
2 active ingredients of Nithiodote:
Na nitrite inj. IV
Na thiosulfate IV
Management of Poisoning:
- Accurate history taking
- Stabilization of patient’s condition
- Physical examination
- Laboratory examination
- Decontamination
- Poison-specific treatment – antidote
- Disposition
History Taking: 5 W’s
Who – demographics (name, age, weight, etc.)
What – identify the drug/ toxin and dose
When – time and date
Where – route of administration and the geographic location
Why – intentional or accidental
Emergency evaluation treatment:
A-irways, B-reathing, C-irculation, D-isability, E-xposure
Essential Laboratory Tests:
• Serum osmolality and osmolar gap
• Electrolytes
• Serum glucose
• BUN and creatinine
• Liver profile
• Urinalysis
• ECG
• Pregnancy test
• Tests to detect specific chemical/drug levels
Decontamination:
• Wash skin and irrigate eyes
• Emesis or gastric lavage
• Charcoal or cathartic
• Hemodialysis, Hemoperfusion
neutralizes the poison by changing its chemical nature or oxidize the poison into non-toxic or insoluble form. Ex, Na thiosulfate
Chemical antidote
one that prevents absorption of the poison. Ex. AC
Mechanical antidote
one that counteracts the effects of poison by producing opposing
physiologic effect. Ex. Naloxone
Physiologic antidote
work by forming a complex with the metal ion, which can then be excreted from the body through urine or feces. Ex. EDTA
Chelating agents
