Psychopharmacology Flashcards
What are some of the SE of anti depressants?
Restlessness, agitation, nausea, GI disturbance, sexual dysfunction, suicidal ideation
What are some of the SEs of SSRIs?
- Sertraline - safest in cardiac disease
- Fluoxetine - Serotonin syndrome
- Citalopram - QT prolongation
- Paroxetine - Discontinuation syndrome
What are some examples of SNRI?
Venlafaxine, dulexetine
What are some of the side effects of SNRIs?
sedation, nausea, sexual dysfunction - more than SNRIs
What are the uses of SNRIs
- GAD
- Moderate depression
- Neuropathic pain - Duloxetine - licensed for fibromyalgia
- Venlafaxine - license in the US for neuropathic pain.
When is mirtazapine used and how does it work?
NASSA: norA and specific serotonin antidepressant
How is mirtazapine used?
Major depressive disorder
What does mirtazapine act on?
Serotonin and NorA
What are some of the side effects of mirtazapine?
Sedation and weight gain
What are some of the uses of tricyclics
- Used for those that don’t response to SSRIs
- Often used at low doses for neuropathic pain
What are some of the SEs of tricyclics?
- Muscarinic
- Histaminic
- QT -> prolongation Arrythmia
Where do MAOI work? What is their MoA?
- MAOI – A (work more on serotonin)
- MAOI – B (work more on dopamine)
Inhibit neurotransmitted reuptake
What should be avoided with MAOI?
- Tyramine - can cause a hypertensive crisis.
- Avoid cheese, wine, pickled meats.
- If changing anti depressant there should be a wash out period of 6 weeks
What is vortioxetine?
All different sorts of serotinergic activities • Effective • Well tolerated – most common side effect is nausea (but less severe than Venlafaxine) • Evidence for improvement in difficult to treat cognitive symptoms • Has recently entered NICE guidance, came in quite quickly as is quite cheap. Very effective. • Can only be prescribed by psychiatrists rather than primary care
What is discontinuation syndrome? How it is caused and what are the most common drugs causing it?
- Antidepressants are not addictive but they can be difficult to stop – dependence syndrome
- Can cause physiological effects when they are stopped
- Sx: sweating, shakes, agitation, insomnia, headaches, irritability, GI sx: cramping, N+V, paraesthesia, clonus
- The shorter the half-life the bigger the problem and when stopping quickly from a high dose
- Trickiest to stop - Paroxetine and Venlafaxine
What are some of the sx of serotonin syndrome?
How is it managed?
- Cognitive – headaches, agitation, hypomania, confusions, coma
- Autonomic – shivering, sweating, hyperthermia, tachycardia, nausea and diarrhoea
- Somatic – myoclonus, hyper-reflexia and tremor
- Mx: usually supportive: fluids and monitoring.
What are anti psychotics and which pathways do they target?
- Neuroleptics: reduce dopamine activity at D2 receptors
- Pathways:
- Mesocortical
- Mesolimbic
- Unwanted pathways: nigrostriatal and tubularfundibular
What are some of the common side effects of antipsychotics?
- Sedation
- Weight gain
- Acute dystonia
What is acute dystonia?
How is it managed?
- Sustained, often painful, muscular spasms, producing twisted abnormal posture
- 50% cases in the first 48 hours, 90% in first 5 days
- Most common: oculogyric crisis, torticollis (twisted neck) opisthonus(spasm of the muscles causing backward arching of the head, neck, and spine), tongue protrustion
- Mx:
- Stop antipsychotic
- Give IM + IV anti cholinergics – procycylidine - continue for 1-2 days after dystonia and consider long term prophylactic
What are some of the examples, features, mechanisms and SEs of typical vs atypical anti psychotics?
What is clozapine and when is it considered?
How is its use monitored?
- D2 and 5HT2 antagonist
- After 2 anti psychotics have not worked
- Most effious: improvements can continue for several months after stopping use
- FBC monitoring
- Weekly for the first 18 weeks
- Then every 2 weeks
- Then monthly
What is clozapine induced agranulocytosis and how is it managed?
- Stop clozapine
- Stop other potentially suppressing drugs e.g. sodium valproate
- Avoid other anti psychotics for a couple of weeks where possible, though if needed ariprozole has less potential for bone marrow suppression
- Contact consultant haematologist as an emergency
- Avoid sources of infection. Consider prophylactic broad spectrum antibiotics
- Lithium: sometimes used for increasing WCC and neutrophil count
- Granulocyte colony stimulating factor (G-CSF): G-CSF – Will release white cells from bone marrow. You will get a spike but this is not a long term fix. Very pain injection
What are some of the specific SEs of clozapine?
- Agranulocytosis and neutropaenia
- Reduced seizure threshold
- Constipation -> GI hypomobility -> fatal bowel obstruction
- Myocarditis (take a baseline ECG should be taken before starting treatment)
- Hypersalivation
- Urinary incontinence
How are anti psychotics managed?
-
Baseline: FBC (can affect bone marrow production causing pancytopenia) ; Lipids; LFT (steatohepatitis); HbA1C. Weight. ECG. Blood pressure and pulse
- Drugs are metabolised by liver rather than kidneys (so U+E are NOT important)
- Weekly: Weight
- Three months: FBC; Lipids; LFT; HbA1C. Weight. ECG. Blood pressure and pulse
- Yearly: FBC; Lipids; LFT; HbA1C. Weight. ECG. Blood pressure and pulse
What is neuroleptic malignant syndrome?
- Rare, life-threatening reaction to antipsychotics
- Causes: Fever, confusion, muscle rigidity, sweating, autonomic instability , delirium
- Death usually due to: Rhabdomyolysis, renal failure, seizures
- RFs:
- High potency dopamine antagonists (typical antipsychotics) in antipsychotic naïve (those who have not taken them before)
- High doses, young men and usually if restraint is involved (maybe due to rhabdomyolysis)
How is neuroleptic malignant syndrome investigated and managed?
- Ix: WCC CRP, Creatine Kinase (Most important to distinguish between NMS and Serotonin Syndrome)
- Mx: Emergency referral to A&E; stop antipsychotics; fluid resuscitation; reduce temperature, sodium bicarbonate to alkalise the urine
- Relax muscles – dantrolene
Give two examples of anxiolytics?
-
Benzodiazapines: lorazepam (shorter half life), diazepam (longer)
- Mechanism: Bind to GABA receptors to potentiate the effect of GABA and therefore reduce excitability of neurones.
- Use very cautiously and for no more than six weeks (usually prescribed for 2-4 weeks)
- SE: benzodiazapine withdrawal syndrome and paradoxical inhibition
-
Beta blockers: propanolol - Limited effectiveness for enduring anxiety disorders
- CI: asthma
What are some of the SEs of benzos and what happens?
- Paradoxical inhibition: caused by frontal lobe supression, diinhibited behaviour more common in elderly pts
-
Benzodiazepine withdrawal symptoms
- Can occur up to 3 weeks
- Sx: insomnia, anxiety, irritability, tremor, loss of appetitve, tinnitus and perspiration
What is the mechanism of pregabalin?
- Bings to voltage gated calcium channels -> increased [GABA synthesising enzyme] -> GABA increases -> neuronal excitability decreases
- Uses; anxiety, neuropathic pain, epilepsy
- Indication short term use;
- SE: sedation and weight gain
What tablets can be used for sleeping?
- Benzodiazepines: Temazepam, Lormatazepam, Nitrazepam
- Nonbenzodiazepines: - Also called Z drugs: Zopiclone, Zolpidem - favoured but probably not much difference between the two (though Z-drugs usually favoured)
- Potential for misuse, dependence, rebound insomnia.
- Use for only two weeks and take for only 5 out of 7 days each week to reduce potential for tolerance
How does lithium work and what are its uses?
- Mood stabilisers
- Narrow therapeutic window
- Kidney excretion
What are the SEs of lithium (short and long term)?
Short term
- GI disturbance (worse on initiation)
- Weight gain
- Polyuria, polydipsia
- Metallic taste
- Fine tremor
Long term
- Hypothyroidism (reversible)
- Renal impairment
Lithium Toxicity: ataxia, confusion, blurred vision - increase fluid intake (dehydration precipitates)
Others: seizures, N+V diarrhoea,
ECG: T wave flattening + inversion
How is lithium monitored?
- 12h post first dose
- Weekly after each dose change till conc. stable
- Normal: every 3 months (stable conc)
- Other: thyroid + kidney - every 6 months
What drugs interact with lithium?
Anything messing with kidneys
- NSAIDs
- Acei
- Diuretics
What are some of the types of anti convulsants?
- Sodium valproate: SE: teratogenic, LFTs - benign hepatitis
- Carbemezapine
- Lamotrigine. SE: stevens johnsons - T4 hypersensitivity
- Pregabalin
SE: thrombocytopenia (check FBC), sedation, weight gain
What are the rversible and irreversible examples of MAOIs?
- Irreversible – more dangerous: Phenelzine; Isocarboxazid
- Reversible – less dangerous: Moclobamide; Tranylcypromine
What needs to be monitored when using venlafaxine
BP - caution with higher doses in Heart Disease
