Mood stabilisers

Question 1

Uses of mood stabilisers

Answer 1

• Used in bipolar affective disorder
• Hypomania, mania, depression or mixed.
• Treatment and prophylaxis of mood episodes

Question 2

Lithium uses

Answer 2

• Used in the acute treatment of mania, the prophylaxis of unipolar and bipolar mood disorder, augmentation therapy in resistant depression and the prevention of aggressive behaviour in patients with learning disabilities.
o Mania (usually with antipsychotic) – more effective than valproate.
o Prevention of manic and depressive relapses
o Treatment resistant depression

Question 3

Lithium mechanism

Answer 3

o Intracellular messenger systems

o NMDA pathways

Question 4

Lithium pharmacokinetics

Answer 4

o Rapidly absorbed
o Diffuses quickly throughout body
o Removed quickly from plasma and more slowly from the body’s total pool.

Question 5

Lithium issues and monitoring

Answer 5

• Sudden cessation can precipitate mania
• Narrow therapeutic range – 0.4-0.8 (toxic at >1.0)
• Test blood levels 12 hours post-dose. Blood should be tested every two weeks at first, then every six weeks once a steady state has been reached.
• Renal reabsorption – maintain hydration
• Blood monitoring weekly then three monthly. Peaks in plasma at 12 hours, so test is only valid if done 12 hours after dose
Baseline ECG, TFT, then TFT and U&E 6 monthly.

Question 6

Lithium side effects

Answer 6

o Polydipsia, polyuria (diabetes insipidus)
o Metabolic – nausea, weight gain, GI disturbance.
o Fine tremor
o Renal - mild renal impairment
o Metallic taste in mouth
o teratogenic
o Cardiac – T wave flattening, widening of QRS
o Thyroid
o Baseline ECG, TFT, then TFT and U&E 6 monthly.

Question 7

Lithium DDRs

Answer 7

o NSAIDS
o Diuretics – thiazides act on sodium channels, which cause a reciprocal increase of lithium in the blood.
o ACE inhibitors
o SSRIs

Question 8

Lithium contraindications

Answer 8

o Renal failure or significant renal impairment
o Heart failure or recent MI
o Untreated hypothyroidism
o Addison’s disease and patients with low body sodium levels.
o Patient unlikely to use the drug safely.

Question 9

Lithium Toxicity

Answer 9

Lithium toxicity – coarse tremor, ataxia, dysarthria, reduced consciousness, convulsions, coma, and death.

Question 10

Sodium valproate uses

Answer 10

• Good for mania, can be more effective than lithium for patients with mixed affective states. Effective in the prophylaxis of both manic and depressive episodes.

Question 11

sodium valproate mechanism

Answer 11

• Multiple actions – GABA, cell signalling, sodium channels

Question 12

Sodium valproate pharmacokinetics

Answer 12

• Rapidly absorbed, peak reached within 2 hours.

* Metabolised in the liver – some metabolites are clinically active

Question 13

Sodium valproate monitoring

Answer 13

• Baseline FBC, LFT, weight, then 6 monthly LFT and FBC

* Blood levels when indicated (toxicity, poor compliance)

Question 14

Sodium valproate side effects

Answer 14

o Tremor, sedation, headache
o GI disturbance – anorexia, nausea, vomiting and diarrhoea
o Hyperammonaemia, thrombocytopenia, hair loss.
o Teratogenic – avoid in childbearing women
o Rarely fulminant hepatic failure

Question 15

Lamotrigine uses

Answer 15

• Used in bipolar with a more depressive pole or anxiety in bipolar. Often used in combination with other drugs, such as lithium.

Question 16

Lamotrigine ADRs

Answer 16

o	GI – nausea, vomiting, diarrhoea
o	Dizziness, tremor, ataxia
o	Stevens-Johnson Syndrome
o	Toxic epidermal necrolysis
o	Bone marrow failure
•	Titrate doses up slowly due to possible adverse effects.

Question 17

Carbamazepine indications

Answer 17

• “Rapid cycling” – multiple mood episodes per year. Mixed affective states.
• Evidence to support use in acute mania and prophylaxis.
• Third line to lithium and valproate.

Question 18

Carbamazepine mechanism

Answer 18

• Sodium channel blocker, affects glutamate, dopamine and NA.

Question 19

Carbamazepine pharmacokinetics

Answer 19

• Slowly but completely absorbed.
• Extensively metabolised, but at least one metabolite is therapeutically active.
• Induces own metabolism. Half-life after repeated treatment is about 20 hours. Also lowers the concentration of other drugs.

Question 20

Carbamazepine monitoring

Answer 20

• Baseline LFT, FBC, U&E (then 6 monthly)

Question 21

Carbamazepine monitoring

Answer 21

o Dizziness, drowsiness, ataxia, headache, visual disturbance
o Hyponatraemia, oedema
o GI – anorexia, nausea, constipation
o Leucopenia (rare)