Alcohol

Question 1

The ethanol present in _____ ml of expired air is equal to the amount in 1 ml of blood.

Answer 1

2100 ml of expired air

Question 2

Ethanol is primarily metabolized by (alcohol dehydrogenase/cytochrome P450 system).

Answer 2

Alcohol dehydrogenase

Question 3

Ethanol is metabolized to ________________ by alcohol dehydrogenase.

Answer 3

Acetaldehyde

Question 4

Acetaldehyde is metabolized by ________________.

Answer 4

Aldehyde dehydrogenase

Question 5

Acetaldehyde is metabolized to ________________ by aldehyde dehydrogenase.

Answer 5

Acetic acid

Question 6

What is the rate limiting step in ethanol metabolism?

Answer 6

Conversion of ethanol to acetaldehyde

Question 7

________ is the cytochrome P450 enzyme responsible for a portion of ethanol metabolism.

Answer 7

CYP2E1

Question 8

(T/F) Almost 100% of ethanol is metabolized and enters the citric acid cycle.

Answer 8

True.

Question 9

In Arkansas, the legally drunk limit is _____ g/dL.

Answer 9

0.08 g/dL

Question 10

What is the mechanism of action for ethanol?

Answer 10

• Enhances activity of GABA at GABAa receptor
• Inhibits excitatory glutamate receptors
• Enhances Ca2+-activated potassium channels
• Inhibits N- and P/Q-type Ca2+ channels
• Replaces water in cavities of protein structure causing allosteric effects

Question 11

A reduction in drug effect as a result of a lowered drug concentration at the receptor is referred to as ____________.

Answer 11

Dispositional Tolerance

Question 12

What are some causes for dispositional tolerance?

Answer 12

• Changes in Absorption
• Changes in Distribution
• Changes in Excretion
• Changes in Metabolism

Question 13

A reduction in drug effect without a change in drug concentration is referred to as __________.

Answer 13

Pharmacodynamic Tolerance

Question 14

What are some causes of pharmacodynamic tolerance?

Answer 14

• Down regulation of receptor
• Change in drug-receptor coupling
• Change in components distal to receptor, such as signaling cascade or secondary messengers

Question 15

When a patient or subject learns to negate the physical or mental side effects of a drug, it is referred to as ___________.

Answer 15

Behavioral Tolerance (Learned Tolerance)

Question 16

The phenomenon in which impairment is greater at a given blood alcohol level when BAC is increasing than for the same blood alcohol level when BAC is decreasing is known as the _________________.

Answer 16

Mellanby effect

Question 17

(T/F) Tolerance developed to a given BAC achieved in a slower rate of consumption may not help moderate the effects of alcohol when the same BAC is achieved by binge drinking.

Answer 17

True.

Question 18

Extensive physiological disturbances upon abrupt discontinuation of drug intake are a sign of __________.

Answer 18

Physical Dependence

Question 19

The severity of physical dependence symptoms is proportional to the:

Answer 19

Level of intake and duration of substance use

Question 20

Ethanol may cause the (vasoconstriction/vasodilation) of peripheral vessels and subsequent (hypothermia/hyperthermia).

Answer 20

• Vasodilation
• Hypothermia

Question 21

Death from alcohol use most often occurs from (hypothermia/respiratory depression/liver failure).

Answer 21

Respiratory depression

Question 22

What changes may ethanol cause within the liver and GI tract?

Answer 22

• Induction of the P450 system
• Fatty degeneration of liver
• Erosive gastritis

Question 23

(T/F) Ethanol produces substantial effects on nearly every endocrine system, interfering with the release of prolactin, growth hormone, and antidiuretic hormone.

Answer 23

True.

Question 24

The increase in urine production associated with ethanol intake is attributed to decreased release of __________.

Answer 24

Antidiuretic hormone (ADH; vasopressin)

Question 25

Most often beginning around a BAC of \_\_\_\_\_\_\_\_, patients present with emesis, anesthesia, coma, severe hypotension, decreased cardiac contractility, and respiratory depression.

Answer 25

0.25 g/dL

Question 26

How is an acute ethanol overdose treated?

Answer 26

* Gastric lavage * Hemodialysis in extreme cases

Question 27

Liver damage is seen in \_\_\_\_% of chronic alcoholics.

Answer 27

100%

Question 28

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ is a condition sometimes seen in alcoholics that results from lesions in the medial thalamic nuclei, **mamillary bodies**, periaqueductal and periventricular brainstem nuclei, and superior cerebellar vermis. It is caused by inadequate intake of thiamine (vit. B1).

Answer 28

Wernicke Encephalopathy

Question 29

Fetal alcohol syndrome (FAS) is diagnosed based off a cluster of 3 features. What are they?

Answer 29

* Microcephaly * Prenatal growth deficiency * Short palpebral fissures

Question 30

Disulfiram inhibits the enzyme \_\_\_\_\_\_\_\_\_\_\_\_\_, causing extreme "hangover" like symptoms on ingestion of alcohol.

Answer 30

Aldehyde dehydrogenase

Question 31

\_\_\_\_\_\_\_\_\_\_\_ acts as an opioid inhibitor and antagonist. By occupying the opioid receptor, ___________ decreases the endogenous "reward" elicited by alcohol. This prevents cravings and alcoholics seeking "just one more drink".

Answer 31

Naltrexone Nal**T**rexone = **T**ipsy = Alcohol treatment

Question 32

\_\_\_\_\_\_\_\_\_\_\_\_\_ modulates the **release of glutamate**, an excitatory neurotransmitter. Glutamate is often overproduced in alcoholics and over time may elicit symptoms such as shaking, hypertension, or seizures. _____________ prevents this by **competing for glutamate receptors (NMDA receptors)**.

Answer 32

Acamprosate

Question 33

\_\_\_\_\_\_\_\_\_\_\_\_\_ is a toxic impurity often encountered in antifreeze, solvent, fuels, or "moonshine" production. It utilizes the same metabolism mechanisms as ethanol, but yields more toxic metabolites. Poisoning with this toxin initially presents as a mild drunken state before progressing to visual disturbances, GI distress, shortness of breath, and respiratory arrest (often the cause of death).

Answer 33

Methanol

Question 34

Methanol is first metabolized to _______________ by alcohol dehydrogenase.

Answer 34

Formaldehyde

Question 35

Formaldehyde is metabolized to ______________ by formaldehyde dehydrogenase.

Answer 35

Formic acid

Question 36

Alcohol dehydrogenase has a (higher/lower) affinity for ethanol than methanol.

Answer 36

Higher affinity for ethanol

Question 37

(T/F) Ingestion of a high dose of ethanol is utilized in methanol toxicity in order to compete for alcohol dehydrogenase.

Answer 37

True.

Question 38

\_\_\_\_\_\_\_\_\_\_\_\_ is a pharmacological competitive inhibitor of alcohol dehydrogenase. It is relatively non-toxic, and is the antidote of choice for methanol and ethylene glycol poisoning.

Answer 38

Fomepizole

Question 39

What is the typical treatment for methanol poisoning?

Answer 39

1. Maintain airway 2. Immediate infusion of sodium bicarbonate (to treat metabolic acidosis) 3. Administer large doses of ethanol 4. Hemodialysis in severe cases 5. Emesis may be attempted in conscious patients if treatment is initiated shortly after ingestion