Psychiatry Drugs

Question 1

SSRIs

Names

MOA

SEs

Interactions

Answer 1

Sertraline, Citalopram, Fluoxetine, Paroxetine

Inhibition of Serotonin reuptake in synaptic cleft

SEs: Insomnia, GI - nausea

Interactions: NSAIDs (must be on PPI in addition), lithium

Question 2

Reversible Inhibitor of Monoamine Oxidase Type A (RIMA)

Name

MOA

SEs:

Answer 2

Moclobemide

Inhibits, MAOI A, preferentially decreases breakdown of serotonin and Noradrenaline

SEs: Tachycardia

Question 3

Tricyclic Antidepressants (TCAs)

Names

MOA

SEs:

Answer 3

Amitriptyline, Nortriptyline, Dosulepin

Inhibition of noradrenline and serotonin reuptake in synaptic cleft

SEs: Anticholinergic syndrome (dry mouth, constipation, urinary retention - due to competitive of Ach), prolonged QT interval

Question 4

Atypical Antidepressants

SEs:

Answer 4

Buspirone (5-HT1A partial agonist)

Venlafaxine (Serotonin and noradrenaline reuptake inhibitor)

Reboxetine (Noradrenaline reuptake inhibitot)

Buproprion (Noradrenaline/Dopamine reuptake inhibitor)

Agomelatine (Melatonin Agonist)

Mirtazapine (Alpha 2 antagonist)

SEs: Anxiety, Aggression

Question 5

Classical/First Gen Antipsychotics

MOA

SEs:

Answer 5

Chlorpromazine, Haloperidol

MOA: CNS D2 Receptor blockade

SEs: Blurred vision, tremor, extrapyramidal symptoms, hypotension

Question 6

Atypical/Second Gen Antipsychotics

MOA

SEs:

Answer 6

Olanzapine, Risperidone, Quetiapine, Clozapine, Amisulpride

MOA: CNS dopamine and serotinin receptor blockade

SEs: Extrapyramidal symptoms (less than classical/First Gen), Hypotension

Question 7

Mood Stabiliser

MOA

SEs:

Interactions

Answer 7

Lithium Carbonate

Neuronal calcium channel blockade

SEs: Tremor, hypothyroidism

Interactions: NSAIDs, ACEi

Question 8

Cholinesterase Inhibitors

MOA:

SEs:

Indications

Answer 8

Donepezil, Galantaine, Rivastigmine

Inhib. acetylcholinesterase

SEs: Nausea & vomiting

Indication - Alzheimer’s disease, mild to mod dementia

Question 9

NMDA receptor antagonise

MOA

SEs:

Indication

Answer 9

Memantine

MOA: NDMA Receptor antagonist

SEs: Constipation, hypertension

Indication: Alzheimer’s disease, mod to severe dementia

Question 10

Non-benzodiazepine Hypnotic

MOA

SEs:

Indication

Answer 10

Zopiclone

Modulation of GABA-A receptor

SEs: Dry mouth, daytime drowsiness

Indication: Insomnia

Question 11

What are Extra-pyramidal side effects?

Answer 11

Extrapyramidal side-effects (EPSEs):

Parkinsonism
acute dystonia
sustained muscle contraction (e.g. torticollis, oculogyric crisis)
may be managed with procyclidine
akathisia (severe restlessness)
tardive dyskinesia (late onset of choreoathetoid movements, abnormal, involuntary, may occur in 40% of patients, may be irreversible, most common is chewing and pouting of jaw)

Question 12

Explain Clozapine monitoring and why it is important?

When should clozapine be used?

Answer 12

WBC monitoring: weekly for 18 weeks, fornightly for a year, then monthly.

Monitor for side effects:

• Agranulocytosis (1%): Sudden fever, muscle weakness, chills, sore throat, mouth ulcers. if leucocyte count below 3000 /mm3 or if absolute neutrophil count below 1500 /mm3 discontinue permanently and refer to haematologist
• Reduced Seizure threshold: can induce seizures in up to 3% patients
• Myocarditis: Baseline ECG should be performed. symptoms - chest pain, sweating
• Hypersalivation

Clozapine should be considered in treatment resistant schizophrenia, where 2 or more treatments have been trialled, each for at least 6-8 weeks