Bipolar Disorder and Mood Stabilizers Overview

Study Notes

Differentiate between pathophysiology of mania and bipolar disorders.
Understand mechanisms of action, adverse effects, and monitoring for drugs treating mania and bipolar disorder.
Justify mood stabilizer choices for patients.
Create care management plans for bipolar disorder patients.
Collaborate on genetic, ethnic, cultural, or gender issues impacting psychiatric prescribing practices.

Mood stabilizers treat acute mania and stabilize both mania and depression.
Combining mood stabilizers may enhance treatment effectiveness.
Understanding individual therapeutic actions is crucial for treatment selection.

Lithium has been used for over 50 years to treat mania.
Its mechanism of action is not fully understood; may involve:
- Inhibition of enzymes affecting signal conduction.
- Modulation of G proteins and gene expression related to growth factors.
Proven to prevent suicide in mood disorder patients.
Comparable or superior efficacy to valproate for mood episodes.
Prescribing is limited due to:
- Need for monitoring.
- Narrow therapeutic index.
- Side effects and potential long-term adverse effects.

Alters sodium transport across nerve and muscle cell membranes.
Side effects include:
- Ataxia, dysarthria, tremor, memory problems, polyuria, polydipsia, weight gain, sedation, possible goiter, and cardiac arrhythmias.
- Gastrointestinal symptoms like nausea and abdominal cramps may resolve, but persistent vomiting and diarrhea indicate toxicity.
Therapeutic range is 0.6-1.2 mEq/L.
Initial plasma level monitoring every 1-2 weeks, then every 2-3 months for 6 months.
Assess dehydration signs and obtain baseline kidney, thyroid function, and EKG before starting treatment.
Caution advised with diuretics due to potential lithium concentration increase.

Effective in treating acute mania and stabilizing mood.
Key agents include:
- Valproate: Blocks sodium channels and increases GABA.
- Carbamazepine: Not detailed but also recognized as effective.
- Lamotrigine: Known for mood stabilization and preventing mania/depression.

Mechanism involves blocking voltage-sensitive sodium channels and enhancing GABA activity.
Side effects include:
- Sedation, gastrointestinal disturbances, weight gain, tremors, dizziness, ataxia, and headaches.
Monitoring requirements:
- Baseline liver function and coagulation tests.
- Track weight and BMI.
- Plasma levels monitored after each dose increase, with targets of 50-125 mcg/mL.
Be mindful of the rare but serious risks of liver failure and pancreatitis.
Most patients may need combination therapy for optimal results.