Patient Safety in Mental Health

Why might a patient need to switch antidepressants?

• no/little response to antidepressant

• ADRs

What is cross-titration/cross-tapering of antidepressants?

• gradually reducing dose of 1 antidepressant while simultaneously introducing and increasing the dose of another

Why must antidepressant switching be carefully planned?

• to prevent interactions

• to prevent serotonin syndrome

• to reduce discontinuation symptoms

What are symptoms of common antidepressant discontinuation?

• flu-like symptoms

• electric shock sensations

• insomnia

• nausea

• imbalance

What is serotonin syndrome?

How can it occur?

• excessive serotonergic activity

• if given a dose increase, interacting drug combination

What are the 3 main groups of serotonin syndrome symptoms?

• mental state changes

• autonomic instability

• neuromuscular hyperactivity

What clinical signs are particularly suggestive of serotonin syndrome?

• clonus and hyperreflexia

• as well as agitation, sweating and fever

Why is lithium considered a high risk med?

What is lithium used for?

• narrow therapeutic index

• maintenance treatment of bipolar disorder

  • can also be used in other specialist psychiatric uses

What is maintenance lithium conc?

What is acute treatment level for lithium conc?

What conc can indicate toxicity?

• 0.4-0.5mmol/l

• 0.6 - 1mmol/l

• >1.2mmol/l

  • note; some patients can experience lithium toxicity symptoms even when conc is <1.2, so if showcasing symptoms always treat

Why are lithium levels checked 5 days after a dose change?

How long after dose is the level checked?

• takes approx 5 half-lives to reach a new steady state

• 8-12 hours post dose

How often monitor steady state lithium plasma level?

• every 3-6 months

How is lithium primarily eliminated?

Why does dehydration increase lithium toxicity risk?

• renal excretion

• dehydration can reduce renal lithium clearance = increase lithium conc

Which drugs can increase lithium toxicity risk?

• NSAIDS (big one)

• some diuretics

• ACE and ARBs

What are signs of lithium toxicity?

• GI symptoms, worsening tremor, slurred speech, ataxia, confusion

  • severe cases - seizure and coma

What to be monitored during long-term lithium treatment?

• kidneys

• thyroid (lithium can cause hypothyroidism and goitre)

• lithium plasma levels

• other blood tests

What are long-term S/E of lithium?

• hypothyroidism

• weight gain

• cognitive dulling

• skin conditions e.g. eczema and psoriasis

• tremor

Is lithium prescribed generally or by brand?

• brand

What formulation of lithium is tablet?

What formulation is solution?

• lithium carbonate IR or SR tablets

• lithium citrate solution

What is neuroleptic malignant syndrome (NMS)?

• rare, potentially life-threatening reaction associated with dopamine blocking drugs

What must happen if clozapine treatment interrupted for >48hours?

• must be re-titrated to the restart protocol (not resumed at full dose)

Why is restarting clozapine at previous full dose after >48 hour break dangerous?

• because clozapine has CV effects - so tolerance to these effects may be lost

• so increases risk of severe hypotension and collapse

Why is combining clozapine and carbamazepine problematic?

• both can affect blood cell production

• can cause bone marrow suppression

What is benzodiazepine tolerance?

What is benzodiazepine physical dependence?

• reduced response to doe following repeated exposure (works less effectively overtime)

• dependent on drug, stopping can cause withdrawal

Do short or long acting benzos cause more withdrawal difficulties?

Why?

• short acting

• conc falls more rapidly → produces earlier withdrawal symptoms

To withdraw or stop benzos a specific conversion needs to be used. What is it?

• convert current benzo to diazepam dose equivalent

• 
  

  

How are benzos to be stopped?

• lower dose by 1/6 to 1/8 fortnightly

• over 6 month period

What is DVLA rule for manic episode where patient ended up hospitalised?

• banned for 6-12 months