bipolar

Question 1

what is bipolar disorder

Answer 1

fluctuation between manic (overactive and excitable) and depressive phases (reclusive and lethargic)

• antimanic drugs used in BD to treat acute mania/hypomania
• antidepressants may also be used for bipolar depression but AVOID in rapid cycling disorder, recent history of mania or rapid fluctuations
• STOP antidepressant if mania/hypomania develops

Question 2

Treatment

Answer 2

acute:
- benzodiazepines
- anti-psychotic drugs: olanzapine, quietiapine, risperidone or haloperidol
- add in lithium or sodium valproate

prophylaxis:
- carbamazepine, lithium or sodium valproate

when stopping antipsychotics - reduce gradually over at least 4 weeks

asenapine - 2nd gen antipsychotic licensed for treatment of moderate-severe acute manic eps

carbamazepine - licensed for prophylaxis in pts unresponsive to lithium

Question 3

important points about lithium toxicity

Answer 3

therapeutic range 0.4 - 1 mmol/L
in acute episodes of BD 0.8 - 1 mmol/L

measure 12 hours after dose
then weekly till stable, 3 monthly for year 1, then 6 monthly thereafter

LITHIUM TOXICITY - SICK + TREMOR
vs
THEOPHYLLINE TOXICITY - SICK + FAST
vs
DIGOXIN TOXICITY - SICK + SLOW

R - renal impairment - incontinence
E - extra pyramidal side effects - TREMOR
V - visual disturbances - blurred vision
N - nervous system disorders - confusion & restlessness
G - GI disorders - N&V

Question 4

lithium SEs

Answer 4

thyroid disorders (amiodarone also causes this)
nephrotoxicity
rhabdomyolysis
QT prolongation
benign intercranial hypertension (headaches)
1st trimester - teratogenic

Question 5

lithium’s interactions

Answer 5

hyponatremia - increases risk of toxicity - diuretics
salt imbalance
serotonin syndrome
QT prolongation
EPSEs - (e.g. metoclopramide, haloperidol)
renally cleared drugs - increase risk of toxicity
reduced seizure threshold
hypokalaemia