L5 Flashcards
What is Vd? Include equation.
= Apparent volume into which a drug distributes
Vd = dose (mg)/ [ ]
Units = L/kg
What does low Vd mean?
Drug resides mostly in plasma
Caffeine
What does high Vd mean?
Drug resides mostly in tissue
Soluble or actively transported
Choroquine
Where can drugs be metabolized?
Liver
Kidneys
Lungs
Where can drugs be eliminated?
Kidneys
Feces
What is the toxic metabolite of Tylenol?
NAPQI
Acteaminophen –> NAPQI
- cP450
What molecule usually detoxes NAPQI?
Glutathione
What is zero order elim?
Fixed amt drug elim per time
Alcohol
What is first order elim?
Eliminated by 1/2 life = half [drug] per unit time
What is saturable elim? Name example.
Elim via 1st order until saturation pt reached –> zero order elim
Phenytoin
What is the difference between half life of elim vs duration of action?
Need to consider BOTH when dosing
1/2 life of elim = how long the drug stays in your system
Duration of action = how long the drug effects can be seen
Describe pediatric poisonings
Single exposure
Acute - short discovery time
Most household products
Which 2 pills are 1 pill killers of kids?
Clonidine - BP & ADHD
Culfonylureas - T2D
Describe adult overdose
Mixed, multiple exposures
Acute or chronic med exp
Delayed presentation
Prescription meds
Describe sympathomimetic toxidrome
= amphetamines, cocaine ↑HR, BP, RR ↑ Temp Mydriasis Agitation Diaphoresis - sweating
Anti-cholinergic toxidrome
= atropine, scopolamine, anti-histamines, synthetic marijuana, K2, spice (sympa overdrive) ↑HR, BP Normal or ↑RR ↑T Mydriasis Agitated DRY, bowel sounds decreased, urine retention
Opioid toxidrome
= heroine, morphine, oxycodone ↓HR, BP ↓↓↓ RR - worried about this! CNS depression, need to maintain respiration!! Miosis Lethargy, coma ↓ bowel sounds, urine retention
Cholinergic toxidrome
= Organophosphates, pesticides (para overdrive = SLUDGE, DUMB BELLS) ↓HR, BP ↑RR ↓Temp - not remarkable Miosis Lethargy, seizure Sweating ↑bowel sounds, peeing the bed
What labs do you get for poisoned pts?
Serum labs based on what you think they’re ODing on
- Acetaminophens & salicylates (aspirin)
- Anti-epileptics: phenytoin, phenobarbital, carbamazepine, valproic acid
- Methemoglobin, carboxyhemoglobin
- Alcohols: ethanol, methanol, ethylene glycol
How do you determine whether to treat an OD?
Nanogram
Above SOLID line = treat with antidote
What is the antidote for tylenol OD?
Acetlycysteine = glutathione precursor
Calculate anion gap
Na - (Cl + HCO3)
What is the mneumonic if AG > 15
MUDPILES Methanol Uremia DKA Phenformin, paraldehyde Iron, isoniazid Lactic acid Ethylene glycol Salicylates
3 options for GI intervetion with overdose
Gastric lavage
Activated charcoal
Whole bowel irrigation
Reqs for gastric lavage
1 hr
Life threatening
Reqs for activated charcoal
Absorbs toxins -> fecal excretion
Most drugs and toxins
What doesn’t charcoal bind
Hydrocarbons
Alcohols
Metals
Reqs for whole bowel irrigation
Slow release pills
Metals
Foreign bodies - body packers
3 mechanism to enhance drug elim
Multiple dose activated charcoal - bile trap, drugs that might get released later
Urine alkalinization = low pKa drugs so preferentially move them into urine
Extracorporeal drug removal = dialysis
5 drugs that are eligible for multiple dose of activated charcoal
Theophylline Phenobarbital Dapsone Cyclopeptide mushrooms Carbamazepine
Which drugs are good candidates for urine alkalinization?
Aspirin
Methotrexate
Req for extracorporeal drug removal
Small molecules
Low protein binding
Small Vd (in plasma)
Water soluble
Antidote for opioids
Naloxone
Antidote for digoxin and crotalidae snake bite
Fab = Abs vs each
Sulfonylurea antidote
Octreotide
Ethylene glycol, methanol antidotes
Fomepizole
Anticholinergics antidotes
Physostigmine
Organophosphorus/carbamate antidote
Atropine
Pralidoxime
