Psychopharmacology

Question 1

Discuss the differences between the typical and atypical anti-psychotics. (2)

Answer 1

Second-generation (atypical) antipsychotics differ from typical antipsychotics in a few ways firstly they bind to the dopamine D2 receptor with less affinity, secondly, they exert their action in the mesolimbic and mesocortical dopamine pathways as opposed to the nigrostriatal pathway, and lastly, they antagonize the 5H12A serotonin receptor a pharmacodynamic property that the typical antipsychotics do not possess. The net result is that SGAs cause less extrapyramidal side effects and have valid efficacy in a host of other neuropsychiatric conditions including mood disorders, anxiety spectrum disorders, and stressor-related disorders.

Question 2

What extra pyramidal signs should you be aware of when using neuroleptics? (1)

Answer 2

• Acute dystonic reaction/tardive dyskinesia- spasm of muscles of tongue, face, neck and back
• Parkinsonism- bradykinesia, rigidity, resting tremor.
• Akathisia- motor restlessness or anxiety

Question 3

What are the core symptoms of neuroleptic malignant syndrome? (2)

Answer 3

Think FEVER”
* Fever,
* encephalopathy,
* vital sign abnormalities (fluctuating BP, tachycardia),
* elevated enzymes,
* rigidity

Question 4

Name 2 indications for psychostimulants?

Answer 4

• ADHD,
• Narcolepsy,
• Obesity,
• Nasal congestion,
• headache,
• hypotension due to anaesthesia

Question 5

Name 2 contraindications for psychostimulants? (2)

Answer 5

• advanced atherosclerosis
• severe hypertension
• glaucoma,
• hyperthyroidism,
• recent stroke,
• cardiac arrhythmias, and
• history of MAOI use in the past 14 days

Question 6

Why are amphetamines contraindicated in patients using Phenelzine?

Answer 6

Phenelzine is a MAOI, and the use of a psychostimulants increases the risk of a hypertensive crisis.

Question 7

State how anticonvulsants work and name 4 neurological side effects (3)

Answer 7

MOA: anticonvulsants increase inhibitory neurotransmission or decrease excitatory neurotransmission (1)

Side effects:
* sedation,
* memory impairment,
* diplopia,
* dizziness (2)

Question 8

Name The two types of sedative hypnotics

Answer 8

Z-drugs and Benzodiazepines

Question 9

Name The neurotransmitter the benzos act on

Answer 9

GABA

Question 10

The amount of time benzos should be used for and the reason

Answer 10

No longer than a month due to their addictive potential

Question 11

Discuss how CYP450 enzymes can cause drug to drug interactions for some antidepressants. (mention at least 2 isoenzymes and 3 antidepressants in your answer) (

Answer 11

Rifampin is an inducer of the isoenzyme CYP2D6, Clozapine is a substrate of the isoenzyme CYP2D6 and therefore Rifampin causes a reduction in the plasma concentration of clozapine.

Question 12

What is the rebound phenomenon associated with benzodiazepines? (1)

Answer 12

Reemergence of symptoms (e.g. anxiety) upon discontinuation of benzodiazepine therapy, often with increased intensity.

Question 13

What are the withdrawal symptoms of benzodiazepines? (2)

Answer 13

withdrawal syndrome which is typically characterized by
* sleep disturbance,
* irritability,
* increased tension and anxiety,
* panic attacks,
* hand tremors,
* sweating,
* difficulty in concentration,
* and nausea.