112b - Mood Stabilizers

Question 1

What is the MOA of Li?

Answer 1

Acts via intracellular signal transduction to alter the activity of several neurotransmitters

Not well understood

No synaptic action

Question 2

What are the indications for lithium?

Answer 2

• Mania
  
  • But can take 1-3 weks to see full affect
  • Not used alone for acute episodes
• Maintenence treatment for bipolar disorder
  
  • More effective at preventing manic vs. depressive episodes
• Bipolar depression
  
  • Better for bipolar depression than most other mood stabilizers
  • Decreases risk of suicide

Question 3

What fetal malformatio is associated with lithium?

Answer 3

Ebstein’s anomaly

(Dysplastic tricuspid valve)

Question 4

In general, what is the mechanism of AEDs?

Answer 4

Increased inactivation of voltage-gated Na+ channels

Results in increased GABA, decreased glutamate activity

Question 5

Which drugs can be used to treat acute mania?

Answer 5

• Valproic acid
  
  • Works quickly
• Carbamazepine
• Lithium
  
  • Does not act quickly; not used as monotherapy
• Antipsychotics
  
  • Especially 2nd generation

Question 6

Which medications can be used to treat manic episodes AND for Bipolar disorder maintenence therapy?

Answer 6

• Lithium
• Valproic acid
• Carbamazepine

Question 7

Which AED can be used as maintenance therapy for bipolar disorder, but not to treat acute manic episodes?

Answer 7

Lamotrigine

Question 8

Which mood stabilizers are most effective in the treatment of bipolar depression?

Answer 8

• Lithium
• Lamotrigine
• 2nd generation antipsychotics

Valproic acid, carbamazepine can be used in acute mania and maintenance, but are not as effective for bipolar depression

Question 9

Which AED carries the lowest risk of sedation and weight gain?

What side effect IS associated with this agent?

Answer 9

Lamotrigine

10% get benign rash, 1% get SJS

Question 10

What are the symptoms of Lithium toxicity?

Answer 10

• Acutely:
  
  • GI symptoms
• Chronically
  
  • Neurologic: tremor, ataxia
  • Renal
  • Cardiac

Question 11

How is lithium toxicity managed?

Answer 11

• Stop lithium
• Rehydrate w/ normal saline (mild)
• Dialysis if severe

Question 12

What might cause a patient previously doing well on Lithium to develop lithium toxicity?

Answer 12

• Dehydration
• Decreased Na+ intake
  
  • Results in increased Li absorption
• Decreased renal blood flow
  
  • Intrinsic renal disease, heart failure, cirrhosis

Question 13

What are the key differences between antidepressants and mood stabilizers?

Answer 13

Both work to treat and prevent depressive episodes

• Mood stabilizers also treat and prevent manic episodes
  
  • And treat depressive episodes without precipating mania
• Antidepressants can precipitate manic episodes
  
  • And do not work to treat manic episodes