Alcohol Flashcards
Ethylene Glycol
- Ethylene glycol used as heat exchangers, in antifreeze formulations, and as industrial solvents.
- Young children are sometimes attracted by the sweet taste of ethylene glycol
physical dependence symptoms
- insomnia
- tremor
- seizure
- nausea/vomiting
- diarrhea
- arrhythmia
Medical applications of ethanol
- 10-15g/day increases serum HDL levels
2. delays onset of labor
Drug that inhibits ADH
Fomepizole
what does ADH do?
converts ethanol to acetaldehyde
What enzyme converts acetaldehyde to acetate?
aldehyde dehydrogenase
drug that inhibits aldehyde dehydrogenase
disulfiram
ethanol facilitates action at which receptors?
GABA-A
Ethanol inhibits
the ability of glutamate to activate NMDA receptors
acute effects of alcohol
- sedation
- loss of inhibition
- impaired judgment
- slurred speech and ataxia
what does aldehyde dehydrogenase do?
converts acetaldehyde to acetate
Effects of alcohol on liver
a) reduced gluconeogenesis –> hypoglycemia
b) progresses on to fatty liver, hepatitis, cirrhosis and liver failure
fomepizole
inhibits ADH
disulfiram
inhibits Aldehyde dehydrogenase
effects of ethanol on the GIT
a) inflammation, scarring, and bleeding of the gut wall
b) increased risk of pancreatitis
effects of ethanol on the CNS
a) peripheral neuropathies
b) thiamine deficiency can occur (Wernicke-Korsakoff)
Effects of ethanol on the endocrine system
a) gynecomastia
b) testicular atrophy
Effects of ethanol on the cardiovascular system
- increased incidence of:
a) HTN
b) anemia
c) dilated cardiomyopathy - ingestion of moderate quantities (10-15g/day) raises serum levels of HDL
Wernicke-Korsakoff Syndrome
- uncommon
- Characterized by:
a) paralysis of the external eye muscles
b) ataxia
c) confused state - can progress to coma and death
- associated with thiamine deficiency
- patients suspected of having W-K syndrome should receive thiamine therapy
- ocular symptoms, ataxia, and confusion often improve with thiamine administration
- most patients are left with a chronic disabling MEMORY disorder known as Korsakoff’s psychosis
Fetal Alcoholic Syndrome (FAS)
➢ Intrauterine growth retardation ➢ Microcephaly ➢ Poor motor coordination ➢ Underdevelopment of the mid-facial region (appearing as a flattened face) ➢ Minor joint anomalities
Treatment of Acute Alcohol Intoxication
➢ Supportive Measure:
• Prevent respiratory depression & aspiration pneumonia
• Give fluids and electrolytes
➢ Pharmacological measure:
• Give glucose to treat hypoglycemia and ketosis
• Thiamin (100 mg) is given to protect against Wernike-Korsakoff syndrome
• Prevent seizures, delirium, & arrhythmia
• Restore K, Mg, & Phosphate ions
Long-term consequences of Wernicke-Korsakoff syndrome
most patients are left with a chronic disabling MEMORY disorder known as Korsakoff’s psychosis
Patient presents with: Insomnia, tremor, anxiety, life threatening seizures, visual hallucinations, delirium tremens
symptoms of alcohol withdrawal
Patient presents with paralysis of the external eye muscles, ataxia and confused state. History of drinking
Wernicke-Korsakoff syndrome
Management of alcohol withdrawal symptoms
a) thiamine
b) restoration of fluid electrolyte balance
c) long-acting sedative-hypnotic drug i.e. BZD (diazepam, chlordiazepoxide)
d) in patients with liver disease Lorazepam or oxazepam are preferred because they don’t require hepatic oxidation
e) Intensity of withdrawal effects reduced by clonidine or propranolol
Drugs approved to treat alcoholism
a) disulfiram
b) naltrexone
c) acamprosate
Ethylene Glycol metabolism
ethylene glycol –(ADH)–> Glycoldehyde –(Aldehyde dehydrogenase)–> Glycol acid–> oxalic acid
MOA of the drug used in management of alcohol withdrawal syndrome
Clonidine = alpha 1 blocker
Toxic effects of Ethylene Glycol toxicity
- Excitation followed by central nervous system depression.
- After a delay of 4–12 hours, severe metabolic acidosis develops from accumulation of acid metabolites and lactate.
- Finally, delayed renal insufficiency follows deposition of oxalate in renal tubules
Drug of choice for management of alcoholic withdrawal in patients with liver disease
Lorazepam or oxazepam
preferred because they don’t require hepatic oxidation
disulfiram
approved to treat alcoholism
➢ Aldehyde dehydrogenase inhibitor
➢ If a patient on disulfiram consumes ethanol then acetaldehyde accumulates
➢ This leads to nausea,vomiting, headache, flushing & hypotension
Other drugs with disulfiram-like effects
- Metronidazole
- Cephalosporins (not all)
- Sulfonylurea hypoglycemic drugs
- Griseofulvin
How is methanol metabolized?
methanol– (ADH)–> formaldehyde –(aldehyde dehydrogenase)–> formic acid
used to manage profound metabolic acidosis
bicarbonate
naltrexone
opioid antagonist approved to treat alcoholism
patient comes in with respiratory failure, a severe anion gap with metabolic acidosis and ocular damage
suspect methanol poisoning
Methanol
➢ Constituent of windshield cleaners & “canned heat”
➢ Intoxication includes:
• visual dysfunction, GI distress, Shortness of breath & loss of consciousness
➢ Methanol metabolized to formic acid, which may cause:
• severe acidosis and retinal damage/blindness
acamprosate
NMDA antagonist approved to treat alcoholism
treatment of methanol poisoning
➢ Gastric lavage
➢ Ethanol is given I.V as it is a preferred substrate for alcohol dehydrogenase
• So methanol is not metabolized to formaldehyde
➢ Fomepizole is given, which is an inhibitor of alcohol dehydrogenase
➢ Rx with bicarbonate (to manage profound metabolic acidosis)
➢ Hemodialysis done in high alcohol levels
Symptoms of Methanol intoxication
- visual dysfunction
- GI distress
- Shortness of breath
- loss of consciousness
Treatment of Ethylene Glycol Toxicity
- Ethanol
- Fomepizole
- Supportive measures
Physiological dependence
deprivation of the drug results in severe anxiety
