110b - Mood Stabilizers Flashcards
What is the MOA of Lithium?
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 weeks to see full affect
- Not used alone for acute episodes
- Maintenence treatment for bipolar disorder
- More effective at preventing manic vs. depressive episodes, but is still a better treatment for bipolar depression than most other mood stabilizers
- Decreases risk of suicide
- More effective at preventing manic vs. depressive episodes, but is still a better treatment for bipolar depression than most other mood stabilizers
What fetal malformation is associated with lithium?
Ebstein’s anomaly
(Dysplastic tricuspid valve)
In general, what is the mechanism of Anti Epileptic Drugs (anticonvulsants)?
- MOA: blockade of voltage gated Na+ channels that enhances the activity of GABA or decreases activity of glutamate
- commonly used agents include valproic acid, carbamazepine, oxcarbazepine, and lamotrigine
Which drugs can be used to treat acute mania?
- Valproic acid (anticonvulsant)
- Works quickly
- Carbamazepine (anticonvulsant)
- 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
- has fewer side effects compared to other mood stabilizers and doesn’t need to be monitored
- a benign hypersensitivity rash can develop in 10% of users can develop further to Stevens Johnsons Syndrome + Toxic Epidermal Necrolysis
What are the symptoms of Lithium toxicity?
- Acutely:
- GI symptoms
- Chronically
- Neurologic: tremor, ataxia
- Renal: polyuria + polydipsia
- Cardiac conduction problems
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
- Decreased Na+ intake —-> results in increased Li absorption
- Decreased renal blood flow due to intrinsic renal disease, heart failure, cirrhosis
- drug interactions that damage renal function
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
How is lithium metabolized/excreted?
is excreted only by the kidney
Side effects of valproic acid?
- has common side effects of weight gain, GI problems, sedation, ataxia, and alopecia.
- rare but serious side effects include hepatoxicity, pancreatitis, and thrombocytopenia
- it is metabolized by the liver and can increase the levels of drugs metabolized by P450s
- is contraindicated during pregnancy b/c increases the risk of neural tube defects
