Mood Stabilisers

Question 1

What are the indications for mood stabilisers?

Answer 1

Also known as antimanic drugs

Used to control acute mania and prevent recurrence of episodes

Long term treatment of bipolar should continue for at least 2yrs from the last manic episode and up to 5yrs if the patient has risk factors for relapse

Question 2

What role do benzodiazepines have in managing mania?

Answer 2

Helpful in the initial stages for behavioural disturbance and agitation but not chronically due to addiction risk

Lorazepam commonly prescribed

Question 3

What role of antipsychotics have in managing mania?

Answer 3

Useful in managing acute episodes of mania

Olanzapine, quitiepine or rispiridone are commonly prescribed

If inadequate response, add lithium or valproate

Discontinuing should take at least 4wks if patient on another antimanic drug; up to 3 months if not or if Hx of manic relapse

Olanzapine can be given long term for management if initially responsive +/- Li/valproate

Question 4

What role does valproate have in managing mania?

Answer 4

Treatment of acute mania in bipolar

Also used as prophylaxis

Unavailable to females of childbearing age due to teratogenic risks

Specialist prescription only

Question 5

What role does lithium have in managing mania?

Answer 5

Prophylaxis and treatment of mania and depression in bipolar

Prophylactic effects may not appear until 6-12 months after initiation

Significant role in reduction of suicidal ideation

Also used for prophylaxis of recurrent unipolar depression, as an adjunct in unresponsive depression and treatment of aggression and self-harm

Question 6

Mechanism of action for lithium?

Answer 6

Unknown:
Interferes with cAMP formation 
Increasing serotonin synthesis, decreasing NAd release
NO pathways
Prevention of neuron apoptosis

Question 7

What monitoring is required?

Answer 7

Narrow therapeutic range so facilities for monitoring need to be available:

Li levels weekly after each dose until concentrations are stable

Whole blood/plasma/serum/urine levels - well controlled levels are 0.5-1.3mmol/l - checked every 3m once established

After change in dose:
Li level taken 1wk later and 12hrs after last dose

Thyroid and kidney function - checked every 6/12

Question 8

What does toxicity involve?

Answer 8

Blood plasma levels at 3-10mmol/l in acute overdose

Can occur acutely with increased plasma levels (dehydration, diuretic use) excess intake (accidental or deliberate) or chronically with accumulation

N+V/D, ataxia, tremor, lethargy, confusion, convulsions, seizure, renal failure, coma

Stop Li, gain plasma level, rehydrate with IV fluid and sodium

Question 9

What are some cautions/contraindications?

Answer 9

Avoid abrupt withdrawal

Cardiac disease, diuretic treatment, elderly (reduce dose), epilepsy (may lower seizure threshold) etc

Pregnancy 1st trimester - teratogen; Addisons; cardiac insufficiency; dehydration; untreated hypothyroidism

Question 10

c

Answer 10

c

Question 11

What are some side effects of Li?

Answer 11

Polyuria, polydipsia, dehydration (Li competitively inhibits ADH action, made worse by dehydration)

Confusion, GI disturbance (N+V, D/C) (hyponatraemia), weight gain, tremors/EPSEs

Serious - hypothyroidism (following 6-18 months of treatment; Li inhibits release of T3/T4), diabetes insipidus, Li toxicity

Question 12

What role does carbamazepine have in managing mania?

Answer 12

Prophylaxis of mania in bipolar disorder if patient unresponsive to other prophylactic drugs

Used in rapid cycling illness (4+ episodes/yr)

Specialist supervision only