Psych Medications

Question 1

Lithium

Answer 1

Lithium:

• MOA: Modulates Dopamine, glutamate and GABA transmission (inhibits dopamine, enhances serotonin release)
• A/E:
• nephrogenic diabetes insipidus
• nephrotoxicity,
• lithium toxicity (hyperreflexxia, increased muscle tone, myoclonic jerks, fine tremor, n/v), metallic taste
• Dose: 750-1000mg daily in divided dose

Other
- have to do lithium level after 12 hrs from most recent dose, therefore typically dose in the evening rather than the AM if possible.

Question 2

Sodium Valproate

Answer 2

Sodium Valproate:

• MOA: blocks voltage-gated sodium channels, inhibits glutamate and enhances GABA
• Indications: primary generalised epilepsy, Bipolar disorder (mood stabiliser)
• A/E: hepatotoxicity, GIT upset, teratogenic, pancreatitis, tremor, weight gain

NOT for use in females of reproductive age given teratogenicity. start on alternative mood stabiliser

Question 3

Clozapine

Answer 3

Clozapine
- MOA: atypical antipsychotic. used in treatment resistant schizophrenia,

A/E

• cardiac toxicity
• agranulocytosis
• metabolic syndrome
• bowel obstruction
• drooling

Question 4

Antipsychotic medications

Answer 4

Antipsychotics
First generation (Haloperidol, Droperidol)
- Dopamine D2 antagonist - prevent positive symptoms
Second generation (Risperadone, quetiapine, aripiprazole, olanzapine)
- Dopamine D2 and 5HT-2 antagonists - prevent positive AND negative symptoms

Adverse effects

• hyperprolactinaemia: galactorrhea,
• Extrapyramidal: ADAPT
• anticholinergic: dry mouth, constipation, blurred vision
• antihistamine: sedation
• cardiometabolic
• orthostatic hypotension
• sedation
• NMS: rigidity (bradyreflexia), hyperthermia, autonomic dysfunction (tachycardia, HTN diaphoresis), raised CK and WCC, altered LOC.

Question 5

SSRIs

Answer 5

SSRIs
Sertraline (Zoloft): Least number of drug interactions, has the biggest dose range (50-200). Widely used. Also low levels in breast milk so is regarded safest in pregnancy and for breast-feeding
- Doseage: 50mg orally once daily, gradually increasing as clinically indicated until 200mg (maximum dose). Increase the dosage by 25-50 mg depending on the response and tolerability.

Fluoxetine: long half-life, can be good in poor adherence, has least weight gain
Escitalopram: maxes at 20mg as there are cardiac risks associated with it.

Indications:

• MDD
• Anxiety disorders

Dosing
- start low, and go slow. start at half the starting dose, sometimes even the quarter, but aim to uptitrate over time.

MOA: selective serotonin reuptake inhibitors, increase post-synaptic concentrations of Serotonin

A/E:

• GIT upset (Serotonin in the gut)
• Increased in suicidal thoughts, agitation
• Hyponatraemia and bleeding (abnormal platelet aggregation) in elderly patients - is of most concern in this demographic
• Serotonin Syndrome (only really in the instance of multiple agents) - careful when switching agents, ensure appropriate wash-out periods
• Sexual dysfunction
• Headache, dizziness

Precautions:
- may provoke a manic episode if utilised in bipolar disorder