Practical Psychopharmacology (Antidepressants and Mood Stabilisers) Flashcards
Common side effects of SSRIs
Headache, GI disturbance (nausea, diarrhoea/ constipation), sleep disturbance/ vivid dreams, sexual dysfunction, suicidal ideation
Contraindications for SSRIs
History of hyponatraemia or predisposition to GI bleeds
Duration of tx with SSRIs
For depressive episode: once well, should continue on the same dose for 6-12 months
For recurrent depression (significant risk of relapse): up to 2 years
Normal response time for antidepressant therapy
Usually seen within 2-4 weeks. At least 4 weeks at an effective dose is needed before determining that the patient has failed to respond
Liscenced SSRI for depression in children
Fluoxetine
Side effects of tricyclic antidepressants
- Cardiotoxic- (QT prolongation, ST elevation, AV block) Particularly problematic in suicidal patients
- Anti-cholinergic/ muscarinic effects: dry mouth, blurred vision, constipation, urinary retention
- Anti-hitaminergic effects: sedation, hypotension, weight gain
- Lethal at overdose and cause discontinuation syndrome
Monoamine oxidase inhibitors (MAOIs) mechanism of action and cheese reaction
- Increase the availability of 5HT and NA in the synapse (older drugs are irreversible), newwer ones are reversible (RIMAs)
- Tyramine Interation= cheese reaction- pts need a special low tyramine diet- hypertensive crisis occurs when taking MAOIs and eating food such as cheese high in tyramine
What causes discontinuation syndrome and what are its symptoms
Can occur in all antidepressant groups especially in SSRIs and venlafaxine: these are NOT THE SAME AS WITHDRAWAL, since antidepressants are not addictive.
Can include GI symptoms, flu-like symptoms, anxiety, trouble sleeping, headache
What is refractory depression and what are its treatment options
Depression which is not responsive to treatment
- Must check medication adherence in a non-accusatory manner, then optimise dose and side effect profile
- Switch antidepressant, initially to an alternative SSRI
- Switch to an alternative antidepressant class e.g Mirtazapine, venlafaxine, TCA
- If all this fails, this is now ‘refractory depression’- try combinations such as addition of an SSRI or augment with lithium or another antipsychotic
What is serotonin syndrome, and what is the triad of symptoms that characterise it?
A medical emergency which occurs when excessive serotonin in the synapses the brain, the incidence is <1%, presents as a TIAD of:
- Altered mental state: agitation confusion, coma
- Neuromuscular changes: hallmark features is myoclonus, hypertonia, hyper reflexia, tremor
- Autonomic dysfunction: tachycardia, HTN, mydriasis (dilated pupils)
Risk factors for the development of seretonin syndrome
Antidepressant use, combination antidepressant, overdose of antidepressants, lithium, ECT, opiates, concurrent use of an SSRI and St John’s Wort- a psychoactive plant
Complications of seretonin syndrome
DIC, rhabdomyolysis, RF, metabolic acidosis, seizures
(treatment involves stopping the antidepressant and giving supportive therapy)
Examples of SSRIs
Setraline, Citalopram, Fluoxetine, Escitalopram, Paroxetine
Drug class and side effects of Mirtazapine
Noradrenergic and specific seretonergic antidepressant (NaSSA)
SEs: Increased appetite (useful if malnourished), weight gain, sedation, dry mouth, headache, dizziness
Drug class and side effects of Venlafaxine and Duloxetine
Seretonin-Noradrenaline re-uptake inhibitors
SEs: similair to SSRIs, need to monitor BP
Examples of TCAs
Amitriptyline, Imipramine
Example and side effects of a RIMA
Moclobemide
SEs: cheese reaction
Drug class and side effects of Trazodone
Seretonin antagonist and reuptake inhibitor (SARI)
SEs: sedation, arrhythmia, hypotension, priapism
Example and uses of a noradrenaline and dopamine reuptake inhibitor
Bupropion- liscenced to help smoking cessation in the UK
Reboxetine drug class and advantages
A selective noradrenaline reuptake inhibitor (NRI)
Less likely to cause sexual dysfunction
Example of a melatonin agonist and serotonin agonist
Agomelatine
Drug class and side effect profile of Vortioxetine
Serotonin modulator and stimulator
Has a good side effect profile: GI effects, dizziness and skin reactions
How is lithium used in the treatment of mental healh disorders?
Lithium is the gold standard mood stabiliser used in BPAD, schizoaffective disorder and severe or refractory depression
Therapeutic range of lithium
0.4-1.0mmol/L
(narrow therapeutic range) would worry about lithium toxicity above this range and the treatment being ineffective below this. Requires regular monitoring (potentially fatal above 2mmol/L)
Complications of lithium treatment
Arrhythmia, CKD, Hypothyroidism, also teratogenic so should be avoided in pregnancy unless the mother is at significant risk.
Common adverse effects of lithium
Fine tremor, mild GI upset, ‘metallic taste’ in mouth, sedation
Effects of persistently elevated lithium levels
- Renal disease
- Polyuria and polydipsia (can cause DI)
- CKD
- Hypothyroidism
- Weight gain
- Persistent tremor
- T wave flattening on ECG
- Mild cognitive impairment
- Change in hair texture
- Mild leucocytosis
Symptoms of lithium toxicity (>1.5mmol/L)
- Coarse tremor
- Marked GI upset
- Ataxia
- Dysarthria
- Impaired conciousness
- Epileptic seizures
- Nystagmus
- Renal failure
What checks should be done before commencing a patient on lithium treatment?
FBC, U&Es, calcium, TFTs, ECG and initially lithium levels will be monitored weekly
What maintenance monitoring should be done for patients on lithium
- 6 monthly bloods including FBC, U&Es, calcium, TFTs, ECG
- 3 monthly lithium levels
- Also need to safety net: advice to stay hydrated, come back if GI symptoms or febrile illness
Which drugs increase the risk of lithium toxicity?
Risks associated with stopping lithium treatment suddenly
Increased risk of manic episodes
Examples of antipsychotic drugs and their uses
Olanzipine, Risperidone, Quitiapine
Rapidly effective for both acute mania and prophylaxis against mania
Must be aware of risk of developing dyslipidaemia and metabolic syndrome when using olanzipine
Examples of Anticonvulsant medication
Sodium Valproate, Carbamazepine, Lamotrigine
Indications and side effects of Sodium Valproate
- Used for acute mania and prophylaxis, but not to be used in women of childbearing age- risk of developmental disorders and congenital malformations.
- Can also cause PCOS
- GI upset (nausea, vomiting, dyspepsia, diarrhoea), tremor, sedation, weight gain, curly/loss hair, ankle swelling FBC abnormalities (leucopenia, thrombocytopenia), abnormal LFTS
Indications and side effects of carbamazepine
- A strong CYP450 inhibitor which is uncommmonly used for prophylaxis against mania
- SEs: Nausea and vomiting, blurred vision, ataxia/, fatigue, hepatic failure, antidiuretic effect (hyponatraemia), FBC abnormalities (leucopenia, thrombocytopenia), skin rashes, abnormal LFTS
Indications and side effects of Lamotrigine
- Used for prophyaxis and in dipolar depression
- Side effects: Nausea and vomiting, rash, headache, sedation, insomnia, aggression
- Rarely causes STEVENS JOHNSON syndrome (epidermal necrolysis)
Management of acute mania
- IF first episode: Antipsychotics (+lithium if ineffective on its own), may stop antidepressant
- IF already on stabiliser: optimise dose then add antipsychotic
- May add adjunctive benzo
Long term management of mania
- Lithium
- Or/in addition use valproate/olanzapine
Management of bipolar depression
- Limited evidence but don’t use SSRIs alone- add antipsychotic or mood stabiliser
Why shoul antidepressants be avoided in rapid cyclinf bipolar disorder
They should only be prescribed if the patient is also taking an antipsychotic or anti-manic agent, because of the risk of triggering a manic episode. This would best be done with the advice of the Mental Health Team. Fluoxetine is the only SSRI recommended by NICE for use in Bipolar Affective Disorder
