Toxic Alcohols

What is the anion gap equation?

Na+ - (Cl- + HCO3-)

What is a normal anion gap?

4-12

What pneumonic can be used to remember what can cause an increased anion gap and metabolic acidosis?

MUDPILES

What is the M in MUDPILES?

methanol

What is the U in MUDPILES?

uremia

What is the D in MUDPILES?

DKA,SKA,AKA

What is the P in MUDPILES?

phenformin, paraldehyde

What is the I in MUDPILES?

isoniazid, INH

What is the L in MUDPILES?

lactate, CO, CN, methemoglobinemia

What is the E in MUDPILES?

ethylene glycol

What is the S in MUDPILES?

salicylates

What are toxic alcohols?

methanol, ethylene glycol, isopropanol

True or False: miscellaneous alcohols are #3 on the PCC list of fatalities

true

What is the clinical presentation of alcohol toxicity?

altered mental status (inebriation), gastrointestinal distress

What is the use of methanol?

gas-line antifreeze, windshield washer fluid, denaturants

True or False: methanol is a high volatility alcohol

true

What is the use of ethylene glycol?

automobile coolant, solvents, de-icers, air conditioning units

True or False: ethylene glycol is a high volatility alcohol

false

What alcohol does not show up on a volatility lab screen?

ethylene glycol

What is a part of the later clinical presentation that is specific to methanol?

visual changes

What is a part of the later clinical presentation that is specific to ethylene glycol?

nephrotoxicity, hypocalcemia

What lab value peaks fist in alcohol toxicity?

osmol gap

What are the toxic metabolites of methanol?

formic acid and formate

What are the toxic metabolites of ethylene glycol?

glycolic acid, ketoadipic acid, oxalic acid, hippuric acid

What is the initial management of alcohol toxicity?

• GI decontamination

• electrolytes and ABG

• ethanol level

• methanol and ethylene glycol level (usually delayed)

• measured osmolality

• consider ADH inhibition

What drugs ate ADH inhibitors?

ethanol, fomepizole

What is the dose of ethanol for alcohol toxicity?

1g/kg

IV:10% solution

PO: 4 shots patron

What BAC should be maintained for alcohol toxicity treatment?

100mg/dL

What is the MOA of fomepizole?

competitive inhibitor of alcohol dehydrogenase

What are the ADRs of fomepizole?

headache, nausea, dizziness, minor allergic reactions

What dose of fomepizole is used in alcohol toxicity?

loading dose: 15 mg/kg

2nd phase: 10mg/kg Q12h x 4 doses

maintenance: 15 mg/kg Q12h

True or False: fomepizole is dialyzable

true

What plays a role in deciding between ethanol and fomepizole?

ethanol is inexpensive, difficult to dose, titrate, and prepare

fomepizole is expensive, easy to dose quicky, and has minimal ADRs

What are the ADRs of ethanol?

CNS inebriation, thrombophlebitis, GI symtpoms

What can be given to help metabolize the toxic metabolites of methanol?

folate, folinic acid, leucovorin

What can be given to help metabolize the toxic metabolites of ethylene glycol?

thiamine (B1)

pyridoxine (B6)

Mg2+

What is the role of sodium bicarbonate in ethylene glycol toxicity?

to correct acidosis

What is the role of sodium bicarbonate in methanol toxicity?

to correct acidosis, reduce ratio of formic acid to formate, ion trapping

What methanol level would indicate the need for hemodialysis?

>50 or >70 if fomepizole used

What ethylene glycol level would indicate the need for hemodialysis?

>62 or >310 if fomepizole used

What would indicate the need for hemodialysis?

high methanol, high ethylene glycol, high osmol gap without another cause, end organ manifestations of toxicity, severe metabolic acidosis (pH <7.15)

What is the osmol gap?

measured osmolality - calculated osmolality = osmol gap

True or False: a normal osmol gap is useless

true

What is a normal osmol gap?

-14 to 10

What major acids are measurable?

lactate, urea, ketones

What should be considered if there is metabolic acidosis, increased anion gap, and increased ketones?

DKA< SKA, AKA, salicylates

What should be considered if there is metabolic acidosis, increased anion gap, and increased lactate?

medical causes: seizures, sepsis

toxin causes: metformin, INH, salicylates

What should be considered if there is metabolic acidosis, increased anion gap, and worsened renal function?

consider uremia

What is the use of propylene glycol?

environmentally safe antifreeze, drug diluent for lorazepam, diazepam, and phenytoin

What is propylene glycol metabolized to?

lactic acid

What is the use of isopropyl alcohol?

rubbing alcohol

What is isopropyl alcohol metabolized to?

acetone

What does isopropyl alcohol toxicity look like?

very inebriating and irritating