Mood stabilizer and anxiolytics

Mood Stabilizers Overview

  • Mood stabilizers are a confusing class of drugs in psychopharmacology, often due to unknown mechanisms of action (e.g., lithium) and variable side effects (e.g., anticonvulsants).

Diagnostic Criteria for Mania

  • Utilize mnemonic DIG FAST to remember symptoms of mania; at least three symptoms meet DSM criteria for mania.

  • Time period for diagnosis: 1 week of elevated mood is sufficient for manic episodes, contrasting with major depression requiring two weeks.

  • Role of Psychiatrists: Bipolar disorder treatment often requires psychiatric supervision due to the necessity for close monitoring of medications like lithium.

Differentiating Bipolar Disorder and Borderline Personality Disorder

  • Shared Features: Depression, impulsivity, suicidality, and transient psychotic symptoms complicate differentiation.

  • Importance: Misdiagnosis leads to inappropriate treatment, e.g., pharmacological treatment for bipolar versus therapy (DBT) for borderline.

  • Key Differences:

    • Mood Fluctuation: Bipolar mood changes last weeks/months; borderline mood swings occur within seconds.

    • Episode Triggers: Bipolar episodes happen independently of life events; borderline moods are often life-event-dependent.

    • Prevalence: Bipolar disorder occurs in ~1% of the population; borderline personality disorder is up to ten times more common.

Pharmacology of Bipolar Disorder Treatment

  • Management Phases:

    • Chronic Phase: Managed with mood stabilizers.

    • Acute Phase: Antipsychotics initiate treatment to manage manic episodes quickly; mood stabilizers take about 10 days to be effective.

  • Avoidance of Antidepressants: Antidepressants can provoke mania and lead to rapid cycling; they are ineffective in bipolar depression.

Lithium as a Mood Stabilizer

  • History: Originally used in the 1800s for gout; recognized for mood stabilization in 1949.

  • Mechanism: Unknown, but it is one of the best-studied drugs for suicide prevention, showing a 7-fold decrease in risk.

  • Therapeutic Index: Lithium has a low therapeutic index, making dosage management critical; target therapeutic range is 1.0 to 1.2 mEq/L. Mnemonic: LITHE-one.

Side Effects of Lithium (Mnemonic: LMNOP)

  • L: Lithium itself.

  • M: Movement or tremors—significant if present.

  • N: Nephrotoxicity; lithium is primarily excreted by the kidneys, causing potential damage, particularly in dehydration.

  • O: Hypothyroidism; lithium’s use correlates with a 6-fold increase in hypothyroidism which can mimic depressive symptoms.

  • P: Pregnancy complications; notably raises the risk of Ebstein’s anomaly (cardiac defect). Mnemonic: LIT for Low Implanted Tricuspid.

Laboratory Monitoring for Lithium

  • Regular labs needed for patients starting lithium to monitor side effects and therapeutic levels; knowing side effects correlates with what needs to be monitored.

Additional Mood Stabilizers - Anticonvulsants

Valproic Acid (also Valproate, Divalproex)

  • Mechanisms: Inhibits voltage-gated sodium channels and increases GABA levels, providing sedative effects.

  • Pregnancy Risk: Known teratogen; risk of neural tube defects (reminder: valproate the folate).

  • Hepatotoxicity Risk: Rare but severe hepatic necrosis potential, remember with liver dinner mnemonic (Halothane, Valproic Acid, Acetaminophen).

Carbamazepine (Tegretol)

  • Mechanism: Similar to valproic acid; inhibits sodium channels, GABA augmentation.

  • Uses: Trigeminal neuralgia, mood stabilization, epilepsy.

  • Risk: Shares agranulocytosis risk with clozapine but less severe.

Lamotrigine (Lamictal)

  • Mechanism: Sodium channel inhibitor but not a GABA receptor modulator; effective for depressive episodes in bipolar disorder.

  • Side Effects: Commonly causes rash; 5-10% chance of Stevens-Johnson syndrome (severe skin condition).

  • Mnemonic: LAMITCHTOL for Lamotrigine and rash association.

Other Anticonvulsants (Limited Efficacy)

Oxcarbazepine (Trileptal)

  • Relation to Carbamazepine: Does not cause agranulocytosis but has not been proven effective for bipolar mood stabilization.

Topiramate (Topamax)

  • Weight Loss: More than 10% weight loss in patients but side effects include cognitive dulling and kidney stones.

  • Nickname: DopaMax; may cause mental dullness despite weight loss.

Gabapentin

  • Used off-label for mood stabilization; primarily indicated for neuropathic pain.

Anxiolytics and Sedatives Introduction

  • Anxiolytics: Used for various anxiety disorders; characterized primarily by enhancing GABA effects.

    • Main classes are benzodiazepines and barbiturates.

  • Benzodiazepines: Increase frequency of GABA channel openings. Advantages over barbiturates include lower toxicity and greater safety margin for overdosing.

  • Barbiturates: Primarily associated with historical overdoses; their use is now limited and includes physician-assisted death.

Benzodiazepines Overview

  • Effective short-term; however, long-term use carries risks of tolerance, dependency, and withdrawal symptoms.

  • Naming Convention: Most end in -azepam and can be identified by the A-Z pattern in names. Mnemonic for half-life distinctions: short Tom, medium cat, long divorce.

Buspirone (Buspar)

  • Under-utilized for generalized anxiety; non-sedating with minimal withdrawal effects; takes weeks to kick in. Mnemonic: Think someone missing the bus regarding anxiety.

Sedatives for Sleep

Temazepam (Restoril)

  • Primarily for sleep; recognized for sedative properties and colloquially termed various nicknames like Vitamin T.

Antihistamines for Sleep

  • Doxylamine (Unisom) found effective for insomnia; however, they disrupt sleep cycles after three continuous usage days.

  • Diphenhydramine (Benadryl) widely used for sedation, particularly in children during travel.

Zolpidem (Ambien)

  • Non-benzodiazepine hypnotic with unique side effects like anterograde amnesia. Associated with unusual behaviors such as sleepwalking.

Eszopiclone (Lunesta)

  • Another non-benzodiazepine hypnotic; similar to zolpidem in efficacy but preferred for sleep treatment over traditional benzodiazepines.

  • Mood stabilizers, such as lithium and anticonvulsants, are utilized in treating bipolar disorder, owing to their complex mechanisms and side effects.

Diagnostic Criteria for Mania

  • DIG FAST mnemonic aids recall of mania symptoms; 1 week of elevated mood suffices for diagnosis. Psychiatrists are often necessary for proper management.

Differentiating Bipolar Disorder and Borderline Personality Disorder

  • Both share symptoms of depression and impulsivity, but misdiagnosis can lead to inappropriate treatment. Bipolar mood changes last longer than those in borderline personality disorder.

Pharmacology of Bipolar Disorder Treatment

  • Chronic Phase: Managed with mood stabilizers.

  • Acute Phase: Antipsychotics for rapid treatment; mood stabilizers take around 10 days. Avoid antidepressants due to risk of induced mania.

Lithium

  • Recognized for mood stabilization since 1949; effective in suicide prevention but has a low therapeutic index (target: 1.0 to 1.2 mEq/L).

Side Effects of Lithium (LMNOP)

  • L: Lithium itself, M: Movement tremors, N: Nephrotoxicity, O: Hypothyroidism, P: Pregnancy complications.

Additional Mood Stabilizers

  • Valproic Acid: Sedative effects; teratogenic risk and hepatotoxicity.

  • Carbamazepine: Similar action to valproic acid, used for trigeminal neuralgia.

  • Lamotrigine: Effective for depressive episodes but carries a rash risk.

Anxiolytics and Sedatives

  • Benzodiazepines: Enhance GABA effects, effective short-term but risky long-term.

  • Buspirone: Non-sedating, minimal withdrawal effects but slow onset.

  • Sedative Options: Temazepam for sleep, with antihistamines disrupting sleep cycles.