Lithium

Question 1

Uses of lithium

Answer 1

mood stabiliser used prophylactically in bipolar disorder

Also used as an adjunct in refractory depression.

Question 2

Describe Lithium’s therapeutic range

Answer 2

narrow 0.4-1.0mmol/L

Question 3

how is lithium excreted?

Answer 3

Renally excreted

Question 4

Lithium mechanism of action

Answer 4

interferes with
- inositol triphosphate formation
- cAMP formation

Question 5

Name common adverse effects of lithium

Answer 5

N+V/ diarrhoea
tremor
nephrotoxicity
thyroid enlargement (hypothyroidism)
weight gain
idiopathic intracranial hypertension
high WCC
hyperparathyroidism (high Ca2+)

Question 6

How does lithium cause nephrotoxicity?

Answer 6

polyuria is secondary to nephrogenic diabetes insipidus

Question 7

ECG changes present in patients taking lithium

Answer 7

T wave flattening/inversion

Question 8

Describe how lithium levels should be monitored

Answer 8

• Sample 12 hours post-dose
• perform weekly after starting lithium and after each dose change until concentrations are stable
• then Lithium level every 3 months

Question 9

What additional tests should be checked every 6 months in patients on lithium therapy?

Answer 9

thyroid and renal function