Nutritional and Toxic Disorders

Question 1

Opiate withdrawal

Answer 1

Occurs within hours to several days of cessation.
Dysphoria, myalgias, nausea, vomiting, rhinorrhea, lacrimation, piloerection, diaphoresis, diarrhea, mydriasis, fever and insomnia.

To differentiate from ETOH/Benzo withdrawal: Increased DTR are typical in ETOH/benzo withdrawal but not opiate.

Question 2

Opioid receptor subtypes and their effects

Answer 2

Delta: analgesia, antidepressant effects, physical dependence

Kappa: spinal analgesia, sedation, miosis, inhibition of ADH release

Mu1: supraspinal analgesia and physical dependence
Mu2: respiratory depression, miosis, euphoria, reduced GI motility and physical dependence

ORL1/orphanin: anxiety, depression, appetite, tolerance

Question 3

Amphetamine mechanism of action

Answer 3

direct release of dopamine and NE and inhibits their reuptake

Question 4

Cocaine mechanism of action

Answer 4

primary: inhibits presynaptic reuptake of dopamine (as well as serotonin and NE)

Question 5

Amphetamine and Cocaine Withdrawal

Answer 5

dysphoria, vivid/unpleasant dreams, increased appetite, insomnia or hypersomnia, agitation, psychomotor retardation

Question 6

Stages of ETOH withdrawal

Answer 6

6-36 h: minor withdrawal symptoms–HA, tremors, diaphoresis, palpitations, insomnia, GI upset, diarrhea, anorexia, agitation, anxiety.
6-48 h: Seizures
12-48 h: ETOH hallucinosis
48-96h: Delirium tremens=delirium, hallucinations, disorientation, agitation, encephalopathy, hypertension, tachycardia, arrhythmias, low grade fever and diaphoresis

Question 7

PCP mechanism of action

Answer 7

noncompetitive antagonist at glutamate NMDA receptor

also affects dopamine, NE, serotonin release and reuptake

Question 8

Hallucinogen (LSD, psilocybin, mescaline) symptoms and mechanism of action

Answer 8

Symp: sensory distortions synesthesias, hallucinations, euphoria, anxiety, tachycardia, palpitations, mydriasis, diaphoresis

Primarily work at serotonin receptors (esp. 5HT2

Question 9

Mercury toxicity

Answer 9

Exposure: fish and shellfish (organic form), inorganic forms in mining, dentistry, chloralkali industries, thermometer factories
If inhaled, a severe interstitial pneumonitis
Intention tremor, cerebellar ataxia, paresthesias, tender and inflamed gums, excessive salivation, swollen salivary glands, personality changes, psychiatric symptoms (anxiety, irritability, fearfulness, memory loss, depression, fatigue)

Question 10

chemotherapy causing peripheral neuropathy

Answer 10

vincristine (sensory and motor), cisplatin, etoposide, taxol (painful dysesthesias)

Question 11

chemotherapy causing leukoencephalopathy

Answer 11

methotrexate

Question 12

chemotherapy causing aseptic meningitis

Answer 12

IT methotrexate

Question 13

chemotherapy causing subacute pancerebellar syndrome

Answer 13

IV cytarabine, 5-fluorouracil

Question 14

chemotherapy causing ICH or ischemic stroke

Answer 14

bevacizumab

Question 15

chemotherapy causing SIADH

Answer 15

cyclophosphamide

Question 16

Lead ingestion

Answer 16

Children: GI symptoms and altered mental status; associated with seizures and increased ICP. Chronic exposure causes neurodevelopmental problems

Adults: motor neuropathy (wrist and finger drop) or sensory neuropathy

Question 17

Ethylene glycol

Answer 17

Patients first look drunk, then develop seizures, nonreactive pupils, lose their corneal reflexes and become comatose and cyanotic

Question 18

Mercury poisoining

Answer 18

Inorganic: tremor and personality changes–>Mad Hatter
Acrodynia (pink extremities, tachycardia, sweating on the trunk, hypertension and encephalopathy)–seen more in kids

Organic: distal paresthesias, ataxia, constriction of visual fields, cortical vision loss

Question 19

Nitrous Oxide abuse

Answer 19

Looks like B12 deficiency BUT
in N2O abuse, you have homocysteine only elevated

In B12 deficiency, homocysteine AND methylmalonic acid are elevated.

This is because N2O inhibits methionine synthase

Question 20

Organophosphate poisoning

Answer 20

Organophosphates bind to acetylcholinesterase–>cholinergic crisis

Diarrhea
Urination
Miosis
Bradycardia
Bronchospasm
Emesis
Lacrimation
Lethargy
Salivation
Seizures

Also cramps, fasciculations

Tx: atropine (anti-muscarinic) and pralidoxime (2-PAM) (speeds up reactivation of acetylcholinesterase)

Question 21

strychnine

Answer 21

Glycine antagonist
Used as adulterant of cocaine

Apprehension, nausea, muscle twitching, extensor spasms, opisthotonus, seizures.
Severe muscle spasms that can lead to rhabdomyolysis and renal failure.

Question 22

Thallium

Answer 22

Affects the Na/K ATPase
Found in rat poison
Acutely vomiting and diarrhea, then severe dysesthesias, cardiac and respiratory failure
Alopecia and axonal neuropathy
Mees lines (also seen in Arsenic poisoning)

Question 23

Toluene

Answer 23

Causes emotional lability, tremor, neuropathy, optic, cerebral and cerebellar atrophy and white matter changes, opsoclonus, ocular dysmetria

Question 24

latrotoxin

Answer 24

produced by black widow spiders
Causes release and blocks reuptake at aminergic, noradrenergic and cholinergic nerve endings

First, pain and target lesion at bite
Then pain and involuntary muscle contractions in abdomen that spreads to limbs
diffuse dysautonomia