Lithium

Question 1

Indications of lithium

Answer 1

Prophylaxis and treatment of mania
Prophylaxis of bipolar disorders
Prophylaxis of recurrent depression

Question 2

Therapeutic index for lithium

Answer 2

0.4-1 mmol/L
Lower end of the range for maintenance therapy and elderly patients

Question 3

Monitoring parameters for lithium

Answer 3

• Renal function - there is a link between CKD and lithium
• U+E’s - esp Na+ as lithium toxicity is worsened by sodium depletion
• Thyroid levels - long term use of lithium is associated with thyroid disorders

Question 4

Lithium and ACE inhibitors

Answer 4

Excretion of lithium reduced by ACEi and ARB causing an increased plasma lithium conc.

Question 5

Lithium and NSAID’s

Answer 5

Excretion of lithium reduced by NSAID’s causing an increased risk of toxicity

Question 6

Lithium and diuretics

Answer 6

Excretion of lithium reduced by thiazides and related diuretics causing an increased plasma conc. and risk of toxicity

Loop diuretics are safer

Question 7

Overview of lithium interactions

Answer 7

• ACEi/ARB’s - increase lithium levels
• NSAID’s - increase lithium levels
• Diuretics - thiazide like diuretics increase lithium levels

Question 8

Toxic effects of lithium

Answer 8

Tremor
Ataxia (impaired co-ordination and balance)
Dysarthria (loss of speech due to loss of muscle control)
Nystagmus (involuntary movement of the eye)
Renal impairment
Convulsions