Psych - Drug misuse

Question 1

What are the symptoms of alcohol withdrawal?

Answer 1

• Symptoms start at 6-12 hours:
  
  • Headache
  • Tremor
  • Nausea
  • Sweating
  • Tachycardia
  • Anxiety
  • Breathing difficulties
• Seizure peak incidence at 36 hrs
• Peak incidence of delirium tremens at 48-72 hrs - this can last as long as 5 days and has high mortality:
  
  • Coarse tremor
  • Tachycardia and HTN
  • Fever
  • Insomnia
  • Confusion
  • Fluctuating motor activity (from hyperexcitabiltiy to lethargy)
  • Delusions
  • Auditory / visual hallucinations

Question 2

What is the mechanism of alcohol withdrawal?

Answer 2

• chronic alcohol consumption enhances GABA mediated inhibition in the CNS (similar to benzodiazepines) and inhibits NMDA-type glutamate receptors
• alcohol withdrawal is thought to be lead to the opposite (decreased inhibitory GABA and increased NMDA glutamate transmission)

Question 3

What medications are 1st line for alcohol withdrawal?

Answer 3

1st line = benzodiazepines e.g. chlordiazepoxide

• Lorazepam - may be preferrable in hepatic failure
• Carbamazepine - also effective in withdrawal
  
  • Anticonvulsant
  • Uses: 1st line for partial seizures, neuropathic pain, bipolar disorder

Question 4

What condition can be caused by thiamine deficiency and who is this condition most commonly seen in?

Answer 4

Wernicke’s encephalopathy

• Commonly seen in alcoholics
• Triad:
  
  • Opthalmoplegia / nystagmus
  • Ataxia
  • Confusion
• Investigations:
  
  • ↓ red cell transketolase (↓ by thiamine deficiency)
  • MRI
• Treatment:
  
  • Thiamine replacement e.g. straight thiamine or Pabrinex (injection containing vitamin C and B i.e. thiamine)
• Complications:
  
  • If not treated, pt may develop Korsakoff syndrome as well

Question 5

What is Korsakoff syndrome?

Answer 5

Neuropsychiatric condition often caused by failure to treat Wernicke’s encephalopathy

• Associated with:
  
  • Wernicke’s encaphalopathy triad: ophthalmoplegia / nystagmus, ataxia and confusion
  • Anterograde + retrograde amnesia - immediate memory intact, but short-term is diminished
  • Confabulations

Question 6

What are the criteria for dependence syndrome?

e.g. alcohol

Answer 6

ICD-10 criteria

Require:

• 3 of the following either …
  
  • ​present together at some point during the previous year OR
  • constantly for 1 month

1. Strong craving / compulsion to take substance
2. Lost control of substance use - difficulty controlling substance-taking behaviour in terms of its onset, termination, or levels of use
3. Tolerance
4. Physiological withdrawal state when substance is stopped/reduced
5. Neglect of other pleasures/interests because of substance use,↑ time for obtaining, taking or recovering from substance
6. Persistant use of substance despite evidence of harmful effects

Another characteristic feature (not part of ICD-10) is narrowing of repertoire i.e. tendency to use the same substance, in the same way, on weekdays and weekends, regardless of social constraints.

Question 7

What medication might be given to deter a patient from drinking alcohol?

Answer 7

Disulfiram

• Produces an acute sensitivity to alcohol i.e. symptoms of hangover are felt immediately with only a small amount of alcohol
• MoA: inhibits acetaldehyde dehydrogenase enzyme

Question 8

Name 2 drugs which might be given to reduce alcohol craving?

Answer 8

Acamprosate and Naltrexone

• Naltrexone can also be used for opiod dependence

Question 9

Which of the following medications is used to treat acute mania in bipolar disorder?

• Methylphenidate
• Lithium
• Olanzapine
• Sertraline
• Lorazepam

Answer 9

Olanzapine

• Methylphenidate (ritalin is a form of this) - used for ADHD
• Lithium - used in mood stabilisation and prophylaxis of mania, depression, bipolar, self-harming behaviour
• Sertraline - anti-depressant thus not recommended for mania
• Lorazepam - sedates patient but doesn’t treat mania

Question 10

What medications are contraindicated when taking Lithium?

• Olanzapine
• Sodium valproate
• Paracetamol
• Naproxen
• Chlordiazepoxide

Answer 10

Naxproxen

lithium is renally excreted and NSAIDs can ↓ renal function

Question 11

What tool can be used to guage alcohol withdrawal severity + guide therapy?

Answer 11

CIWA-Ar

(Clinical Institute Withdrawal Assessment for Alcohol, revised)

• 10 questions
• Score (max = 67):
  
  • ≤8 = absent or minimal withdrawal
  • 9-19 = mild to moderate withdrawal
  • ≥20 = severe withdrawal
• Benzodiazepines - used to control psychomotor agitation + prevent progression to more severe withdrawal
  
  • Chlordiazepoxide (Librium)
  • Lorazepam (Ativan)
  • Diazepam (Valium)