Psychotropic medication

Psychotropic medication includes some of the most commonly prescribed medication in the the world. This article will cover the types of medication you will tend to encounter, important side effects, monitoring and emergencies.

Mood disorders

When initiating patients on anti-depressant medication it is important to follow them up within 2 weeks. This is because one of the earliest benefits is an increased motivation, which can paradoxically increase the risk of suicide.

Antidepressants
  • SSRIs (selective serotonin reuptake inhibitors) e.g. sertraline, citalopram, fluoxetine (1st line in <18), paroxetine
  • SNRIs (serotonin noradrenaline reuptake inhibitors) e.g. venlafaxine, duloxetine
  • NaSSA (noradrenergic and specific serotonergic antidepressant) e.g. mirtazapine
  • TCAs (tricyclic antidepressants) e.g. amitriptyline, gabapentin – these are not recommended to be used due to risk in overdose.
Screenshot 2022 01 24 at 19.47.29

NB: antidepressants are also indicated in anxiety and eating disorders.

Lithium
  • Indication: bipolar affective disorder (BPAD), severe depression
  • Forms: lithium carbonate or citrate
  • MOA: not fully understood – permeates voltage-gated Na+ ATPase channels
  • Has a very narrow therapeutic index (0.4-1.0mmol/L) so must prescribe by same brand and form, and advise on regulating hydration status
  • ADRs:
    • Common: metallic taste, GI upset, fine tremor, polydipsia, polyuria
    • Notable: weight gain, acne, hypothyroidism, nephrogenic diabetes insidious, hypercalcaemia (due to increased PTH)
    • Serious: arrhythmia (T wave flattening), risk of toxicity
  • Monitoring:
    • Baseline: ECG, blood tests (FBC, U&Es, LFTs, TFTs, bone profile)
    • Serum lithium: take level 12 hours after dose – 1 week after initiation/dose change then weekly till stable
    • 6 monthly: U&Es, TFTs, bone profile
Other mood stabilisers
  • Semisodium valproate:
    • Used for manic episodes of BPAD
    • ADRs: GI upset, weight gain, hepatotoxicity, acute pancreatitis
    • Teratogenic – neural tube defects
  • Carbamazepine:
    • Used for rapid cycling BPAD
    • ADRs: GI upset, agranulocytosis, SIADH, Stevens-Johnson syndrome
  • Lamotrigine:
    • Used for depressive episodes associated with BPAD
    • ADRs: GI upset, fatigue, blurred vision, Stevens-Johnson syndrome
    • Teratogenic – oral cleft defects

Antipsychotics

  • 1st gen ‘typical‘: haloperidol, zuclopenthixol, chlorpromazine
  • 2nd gen ‘atypical‘: olanzapine, risperidone, quetiapine, clozapine
  • 3rd gen ‘atypical‘: aripiprazole
ADRs
  • Common: GI upset, sedation, postural hypotension
  • Notable: metabolic disturbance (weight gain, dyslipidemia), sexual dysfunction (hyperprolactinemia), extrapyramidal side effects
  • Serious: QT prolongation, decreased seizure threshold, neuroleptic malignant syndrome

‘Atypical’ antipsychotics have a higher affinity for 5-HT2A receptors and a lower affinity for D2-like (dopamine) receptors making extrapyramidal side effects milder and therefore being the preferred agent. Aripiprazole is considered a 3rd-gen atypical antipsychotic as it is a newer drug and a partial D2 agonist, so tends to have the least side effects.

What are the extrapyramidal side effects (EPSEs)?
Parkinsonism: treated with procyclidine. Akathisia (inner restlessness): treated with propranolol. Acute dystonia (painful muscular spasms): treated with procyclidine. Tardive dyskinesia (involuntary repetitive movements of lips, tongue and jaw): difficult to treat, can treat with tetrabenazine
Monitoring
  • Before starting: assess cardiovascular risk
  • Baseline: BMI, BP, ECG, bloods (FBC, HbA1c, U&Es, LFTs, TFTs, CK, prolactin)
  • Blood tests should be monitored every 6 months
Clozapine
  • ‘Atypical’ antipsychotic used in treatment resistant schizophrenia
  • Unique ADRs: agranulocytosis, constipation, myocarditis, hypersalivation, nocturnal enuresis
  • Requires re-titration if missed 2 days of dosing
  • Has unique FBC monitoring due to risk of agranulocytosis – must monitor FBC weekly for 18 weeks then fortnightly till a year
images
‘Traffic light’ monitoring for clozapine

Emergencies

Lithium toxicity
  • ABCDE – involve ITU and notify liaison psychiatry
  • History + neurological examination
  • ECG
  • Bloods: U&Es, TFTs, serum lithium:
    • Serum lithium >1.5mmol/L: coarse tremor, weakness, drowsiness
    • Serum lithium >2.0mmol/L: hyperreflexia, seizures, renal failure
  • IV volume replacement if mild/moderate, haemodialysis if severe
Serotonin syndrome VS Neuroleptic malignant syndrome
Screenshot 2022 01 24 at 21.09.39

Written by: Dr Muhammad Zain Haq, Psychiatry Lead (F2)
Reviewed by Dr Patrick Ezeani (Consultant Psychiatrist)

How useful was this post?

Click on a star to rate it!

Average rating 5 / 5. Vote count: 5

No votes so far! Be the first to rate this post.

As you found this post useful...

Follow us on social media!

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?

Related Posts

Mental Health 3
Anxiety disorders
Anxiety is a commonly experienced symptom as part of the body’s...
Prescribing image
Prescribing in Old Age Psychiatry
The general prescribing principles from both Old Age Psychiatrists...
Risk
Risk assessment
Determining the risk of harm to the patient, and sometimes to...

Leave a Comment

Your email address will not be published. Required fields are marked *

Follow us

Our Newsletter

Trending Now

Ranking Foundation Jobs
If you’re worried about not getting your top choice, you shouldn’t worry. It doesn’t...
Junior Doctor Pay Calculator
We’ve created a junior doctor pay calculator which will help you better understand your salary,...
Passing the Prescribing Safety Assessment (PSA)
The PSA is aimed at final year medical students and those graduating overseas to assess their competency...
How to take a psychiatric history
Psychiatry, as a specialty is unique in that diagnostic methods, rely very heavily on symptomatology,...
Fluid Balance
Almost every patient admitted to hospital receives IV fluids at some point in their journey. However,...
Referral Cheat Sheet
Our referral cheat sheet is our most popular resource having been downloaded thousands of times! It has...
Audits & Quality Improvement Projects (QIPs)
Audits & QIPs are a way to identify issues, drive changes and assess the effects they have. It is...

Sign up for our awesome resources

Join over 25,000 users who have signed up for our free weekly webinars, referral cheat sheet & other amazing content!