Mood Stabilisers (bipolar)

Question 1

how does lithium act as a mood stabiliser??

Answer 1

1- decreases pre synaptic dopamine by inactivating GPCRs and acting on second messengers to decrease neurotransmission
2-decreases glutamate by downregulating NMDA receptors and acting on second messengers to decrease neurotransmission
3- increases GABA by upregulating GABA-B receptors

Question 2

Side effects of lithium

Answer 2

1-renal (Polyuria/nephrotoxicity)
2-hypothyroidism 
3-ECG changes 
4-leukocytosis 
5-mild cognitive effects 
6-GI, weight gain, dry mouth 
7-fine hand tremor/muscle weakness

Question 3

Caution lithium in

Answer 3

1-pregnant (increases risk of Epstein’s anomaly)
2-breastfeeding 
3-thyroidpathies
4-sick sinus syndrome 
5-renal impairment

Question 4

What can cause lithium toxicity and how to treat it?

Answer 4

Old/dehydration/NSAIDS/cox-2 inhibitors/thiazides/ACE in

Saline diuresis and haemodialysis if lithium > 4mmol

Question 5

Mode of action for Na valproate in treating bipolar

Answer 5

Enhances GABA transmission

Question 6

Contraindications for na valproate

Answer 6

Women of child bearing age (teratogenic)

Lamotrigine and amitriptyline as it’s metabolised by CYP in liver

Question 7

Lamotrigine mode of action to treat bipolar??

Answer 7

Decreases glutamate

Question 8

Side effects of lamotrigine

Answer 8

Stephen Johnson syndrome
Toxic epidermal neurolysis
Therefore titrate slowly

Question 9

How to treat bipolar

Answer 9

Treat depression with antipsychotic, fluoxetine, lamotrigine

Treat mania with antipsychotic, Lithium/Na valproate

Long term use Lithium>Na valproate> antipyschotic