Psych Drugs

Question 1

Name the pathway responsible for +ve SZ symptoms

Answer 1

Mesolimbic pathway

Ventral Tegmental Area -> Nucleus Accumbens

Improvement when reduced DA due to APs

Question 2

Name the pathway responsible for -ve SZ symptoms

Answer 2

Mesocortical pathway

Ventral Tegmental Area -> Cortex

Worsen when reduced DA due to APs

Question 3

Name the pathway responsible for EPSEs

Answer 3

Nigrostriatal pathway

Substantia Nigra -> Striatum

Parkinsonian Sx when reduced DA due to APs

Question 4

Parkinsonian Sx examples (3)

Answer 4

Cog-wheel rigidity
Mask facies
Resting tremor

Question 5

Name the pathway responsible for hyperprolactinaemia

Answer 5

Tuberofundibular pathway

Hypothalamus -> Pituitary Gland

Increased prolactin when reduced DA due to APs

Question 6

Effects of hyperprolactinaemia (4)

Answer 6

Amenorrhoea - due to decreased FSH
Galactorrhoea
Gynaecomastia
Sexual dysfunction

Question 7

Two examples of FGAs

Answer 7

Haloperidol

Chlorpromazine

Question 8

Mechanism of action of FGAs

Answer 8

Inhibit D2 receptors

Question 9

What receptors are also blocked by FGAs

Answer 9

HAM-1

Histamine-1 block -> weight gain and sedation
Alpha-1 block -> orthostatic hypotension and sexual dysfunction
Muscarinic-1 block -> dry mouth etc

Question 10

Mechanism of action of SGAs

Answer 10

Inhibit D2 and 5-HT2a receptor

Question 11

How do SGAs reduce EPSEs?

Answer 11

5-HT2a block causes a slight increase in dopamine production, preventing complete blockade of D2 receptors

60% D2 block = therapeutic level
80% D2 block = EPSEs

Question 12

S/Es of SGAs

Answer 12

WEIGHT GAIN - esp Olanzapine (HAM-1 block)
Dyslipidaemia - may need statin
Hyperprolactinaemia - esp. Risperidone
Agranulocytosis - Clozapoine

Question 13

Features and treatment of acute dystonia

Answer 13

Features = sustained muscle contraction eg. occulogyric crisis, torticollis

Treatment = Procylidine (anticholinergic)

Question 14

Features and treatment of akathisia

Answer 14

Features = unbearable restlessness, pacing, tapping

Treatment = propranolol

Question 15

Features and treatment of tardive dyskinesia

Answer 15

Features = lip smacking, repetitive and uncontrolled movements

Treatment = Tetrabenzine and discontinue AP
Clozapine may help

Question 16

Features of Neuroleptic Malignant Syndrome (4)

And blood test features (3)

Answer 16

Features = fever, tachycardia, muscle rigidity and confusion

Blood tests = increased CK, K+ and WBC

Question 17

Treatment of Neuroleptic Malignant Syndrome

Answer 17

3D’s
Discontinue AP
Dantrolene - protective for ANS
DA-agonist

Question 18

What investigations do you need before starting APs (10)

Answer 18

FBC
U+E
LFT
HbA1c
Prolactin
Lipids
Weight
BP
ECG
Waist circumference

Question 19

How long to trial an SSRI for before changing?

Answer 19

4 weeks - if no response consider changing

Question 20

S/Es of SSRIs that you need to tell patients (5)

Answer 20

N&V - will stop after few weeks
Sexual dysfunction
Short-term anxiety - will go after few weeks
Suicidal ideation - give phone numbers

Serotonin Syndrome

Question 21

Other SSRI S/Es to bear in mind (2)

Answer 21

GI bleeds - careful with elderly

Hyponatraemia - check renal function

Question 22

What are the features of Serotonin Syndrome?

Answer 22

Restlessness
Fever
Tachycardia
Myoclonus
Confusion
Vomiting
Seizures