Mood Stabilizers and Related Psychopharmacology

Overview

• Mood stabilizers: confusing drug class due to unknown mechanisms or multiple body area effects.
• Lithium: unknown mechanism, requires close monitoring.
• Anti-convulsants: work in multiple body areas, unpredictable side effects.

Diagnostic Reminders

• Mania: Use mnemonic "DIG FAST" to remember symptoms (need at least 3 for diagnosis).
• Bipolar Disorder: Requires psychiatrist treatment; differentiation from borderline personality disorder is crucial.

Distinguishing Bipolar from Borderline Personality Disorder

• Bipolar Disorder: Mood changes happen over weeks/months, episodes occur independently of life events.
• Borderline Personality Disorder: Mood dependent on life events, particularly interpersonal relationships.
• Prevalence: Bipolar is rarer (~1% of population) compared to borderline (up to 10%).

Treatment Phases of Bipolar Disorder

• Chronic Management: Always involves mood stabilizers.
• Acute Phase: Antipsychotics may be used to bridge time before mood stabilizers work.
• Antidepressants: Avoid in bipolar disorder; can induce manic episodes.

Lithium

• History & Mechanism: Used since 1800s, mechanism unknown.
• Suicide Prevention: Shown to reduce suicide risk in bipolar patients.
• Side Effects:
  • Low therapeutic index (dose close to toxic levels).
  • Use mnemonic "LMNOP" for side effects:
    • L: Lithium
    • M: Movement (tremors)
    • N: Nephrotoxicity
    • O: Hypothyroidism
    • P: Pregnancy problems

Anticonvulsants

• Valproic Acid:
  • Mechanisms: Inhibits sodium channels, increases GABA.
  • Side Effects: Teratogenic effects, hepatic necrosis.
• Carbamazepine:
  • Uses: Trigeminal neuralgia, mood stabilization, epilepsy.
  • Risk of agranulocytosis.
• Lamotrigine:
  • Use: Better for depressive episodes in bipolar.
  • Side Effects: Rash, potential for Stevens-Johnson syndrome.

Other Medications

• Oxcarbazepine, Topiramate, Gabapentin:
  • Off-label use for mood stabilization; not FDA-approved for bipolar.

Anxiolytics and Sedatives

• Benzodiazepines and Barbiturates:
  • Benzos increase frequency of GABA channel opening; barbiturates increase duration.
  • Benzos preferred due to lower toxicity.
• Buspirone: For generalized anxiety, lacks immediate effects of benzos.

Sedatives for Sleep

• Temazepam: Often used for sleep, part of benzodiazepine class.
• Antihistamines (Doxylamine, Diphenhydramine): Available over-the-counter, disrupt sleep cycle.
• Zolpidem (Ambien): Non-benzo hypnotic, can cause sleepwalking.
• Eszopiclone (Lunesta): Similar to Zolpidem, preferred for sleep.