Decon, enhancing elimination, antidotes Flashcards
Hemodialysis effectively removes valproic acid at toxic, but not therapeutic, concentrations because what is true at toxic concentrations?
A.A greater proportion is not protein bound
B.Intracellular binding falls
C.It has a lower volume of distribution
D.It can be absorbed to dialysis membranes
E.It is dissociated into the more diffusible nonionic form
A. At higher toxic concentrations, a higher proportion of the drug is free in the plasma and more available for removal by hemodialysis or hemofiltration. At therapeutic concentrations, a large proportion is protein bound, but as the concentrations rise, the protein-binding sites are saturated and free valproic acid concentrations increase.
With regards to succimer, which statement is false?
A.It has a sulfur odor and flatulence can be a fire hazard.
B.It mobilizes lead from soft tissues and even bone when combined with EDTA
C.It can facilitate absorption of lead from the gut
D.The injections are very painful and those with peanut allergies cannot receive this therapy.
E.Patients who have lead in their gut must have it removed prior to starting chelation.
D. Painful injections and peanut allergies are true for BAL – British Antilewsite. Succimer is given orally.
Besides benzos, what is the treatment for seizures from the following substances?
A.Carbamates/OPs _____________________
B.Hypoglycemics _______________________
C.Mushrooms (gyromitra) _________________
D.Anticholinergics _______________________
E.Isoniazid ______________________________
- Carbamates and organophosphates – atropine and 2 PAM
- Hypoglycemics – dextrose and octreotide
- Gyromitra mushrooms (monomethylhydrazine) – pyridoxine
- Anticholinergics – Physostigmine
- Isoniazid – pyridoxine
In what situations would decontamination with water not be recommended?
Water should not be used for any reactive alkali metals that form strong bases in water, like sodium, potassium, lithium, cesium, rubidium, dusts of pure magnesium, sulfur, strontium, titanium, uranium, yttrium, zinc, zirconium.
With the following treatment options, describe instances where you would not give this as a therapy.
- Physostigmine
- Beta blockers
- Calcium
- Class 1A, 1C, and III antiarrhythmics
- Methylene blue
- BAL
- HBO – hyperbaric oxygen
- Sodium nitrite
- Physostigmine – don’t give for wheezing/reactive airway disease, use of succinylcholine for intubation, TCAs on board, QRS >100, AV block/bradycardia
- Beta blockers – never use in sympathomimetic toxidrome presentations because the selective beta blockade may result in unopposed alpha stimulation
- Calcium – never give in digoxin toxicity with hyperkalemia – can worsen bradycardia and arrhythmias
- Class 1A, 1C and III antiarrhythmics – can worsen sodium channel blockade
- Methylene Blue – not for use with those with G6PD deficiency
- BAL – not for use for those with peanut allergies
- HBO – not for use for those with pneumothorax
- Sodium nitrite is not indicated for cyanide toxicity with smoke inhalation
Which would be most completely absorbed by 50 grams of AC?
A.50 tablets of cetirizine
B.50 SR tablets of theophylline 300mg
C.50 tablets of lithium 300mg
D.100ml of 40% alcohol
E.100 tablets of ferric chloride
Answer: A. Antihistamines are well absorbed to AC. ETOH is poorly absorbed by AC. Lithium and iron ions are too small to bind with AC. Theophylline would be better managed with MDAC doses, especially with this ER preparation.
In which situation should AC be avoided?
A.ASA overdose with a defiant attitude
B.An alert child who ate a mushroom while foraging with the parents
C.A child who ingested some campho-phenique
D.An accidental quadruple dose of ER sotalol
E.A child who ingested mother’s carbamazapine
Answer C: Possible CNS deterioration and/or seizures from a camphor product should definitely be a good reason to avoid activated charcoal. The other reasons would be good reasons.
Seven reasons for MDAC
- Drugs with significant recirculation
- Prolonged ½ life
- Small Vd
- Limited protein binding
- Sustained release and enteric coated forms
- Onset of organ failure where elimination is thwarted (such as bezoars)
- Drugs with increased transport across cell membranes
Six Drugs with Enterohepatic Recirculation
- Carbamazapine
- Digitoxin
- Colchicine
- Dapsone
- Thallium
- Valproic acid
Hemodialysis would be expected to be most useful for enhancing the elimination of a XB (xenobiotic) with which characteristic?
A.Low degree of protein binding
B.High lipid solubility
C.High molecular weight
D.High volume of distribution (Vd)
E.Minimally ionized at physiological pH
Answer A: Low degree of protein binding. Hemodialysis removes solutes by diffusion from blood – dialysate across a semipermeable membrane. Molecules bound to plasma proteins, which in general, are too large to cross the membrane, will not be dialyzed. Molecules with a large Vd are bound to proteins or tissues or are soluable in non aqueous phases, such as lipids, and are not diffusible. Diffusion is also limited with XB with high molecular weight. Molecular charge does not directly affect the success of hemodialysis.
Antidote for Cyanide
1.Hydroxocobalamin, sodium nitrate/thiosulfate
Antidote for Iron
Deferoxamine
Antidote for Isoniazid
Pyridoxine
Antidote for Methemoglobinemia
methylene blue
Antidote for organophosphate poisoning
Atropine and 2-PAM
Antidote for Sulfonylureas
Octreotide
Antidote for Valproic acid
L-carnitine