110: Mood Stabilizers Flashcards
What is the MOA of Li?
Acts via intracellular signal transduction to alter the activity of several neurotransmitters
Not well understood
No synaptic action
What are the indications for lithium?
- 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
What fetal malformation is associated with lithium?
Ebstein’s anomaly
(Dysplastic tricuspid valve)
In general, what is the mechanism of anti-convulsants?
Increased blockade of voltage-gated Na+ channels
Results in increased GABA, decreased glutamate activity
More inhibition, less excitation→ calm everything down
Which drugs can be used to treat acute mania?
- Valproic acid
- Works quickly
- Carbamazepine
- Lithium
- Does not act quickly; not used as monotherapy
- Antipsychotics
- Especially 2nd generation
Which medications can be used to treat manic episodes AND for Bipolar disorder maintenence therapy?
- Lithium
- Valproic acid
- Carbamazepine
Which AED can be used as maintenance therapy for bipolar disorder, but not to treat acute manic episodes?
Lamotrigine
Which mood stabilizers are most effective in the treatment of bipolar depression?
- Lithium
- Lamotrigine
- 2nd generation antipsychotics
Valproic acid, carbamazepine can be used in acute mania and maintenance, but are not as effective for bipolar depression
Which AED carries the lowest risk of sedation and weight gain?
What side effect IS associated with this agent?
Lamotrigine
10% get benign rash, 1% get SJS
What are the symptoms of Lithium toxicity?
- Acutely:
- GI symptoms
- Chronically
- Neurologic: tremor, ataxia (difficulty balancing/walking)
- Renal
- Cardiac
How is lithium toxicity managed?
- Stop lithium
- Rehydrate w/ normal saline (mild)
- Dialysis if severe
What might cause a patient previously doing well on Lithium to develop lithium toxicity?
- Dehydration (think a bad stomach bug)
- Decreased Na+ intake
- Results in increased Li absorption
- Decreased renal blood flow
- Intrinsic renal disease, heart failure, cirrhosis
What are the key differences between antidepressants and mood stabilizers?
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
Which mood stabilizer is the lowest risk in pregnancy?
Lamotrigine
Valproic acid and carbamezapine → neural tube defects
Lithium→ Ebstein’s Anamoly
How does valproic acid interact with lamotrigine?
Valproic acid slows the metabolism of lamotrigine → INCREASES SERUM LEVELS
When starting valproic acid, would decrease dose of lamotrigine.
