MOOD STABILIZERS

Carbamazepine (Tegretol)

 

HALF-LIFE: Initially 25-65 hours, then 15 hours after 2-4 weeks
STARTING DOSE: 200mg PO BID
TARGET DOSING RANGE: 400mg-600mg PO BID
BEST TIME TO DOSE: Any
HOW TO DOSE:
>Initial 200mg PO BID
>Increase by 200mg/d every 3-4 days to target dose
>Max dose 800mg PO BID
PREGNANCY: AVOID
BREASTFEEDING: AVOID
FDA INDICATIONS:
1) Seizures
2) Trigeminal Neuralgia
3) Acute mania associated with Bipolar Disorder (Equetro)

 

ADDITIONAL INFORMATION

 

  • Proposed Mechanism of action: Blocks voltage sensitive sodium channels
  • Reports of CNS toxicity (dizziness, diplopia) associated with combination of carbamazepine and lamotrigine 
  • Metabolized primarily by CYP3A4 and also induces its own metabolism by inducing CYP3A4
  • Induces multiple other CYP450 isozymes as well as P-Glycoprotein
  • May test positive (false positive) for tricyclics (TCAs)

 

Notable Adverse Effects:

 

  • Leukopenia
  • Thrombocytopenia
  • Rare Aplastic Anemia (fever, fatigue, pallor, bleeding gums)
  • Risk of Aplastic Anemia increased by coadministration with clozapine
  • Rare Agranulocytosis
  • Rash (increased risk of SJ/TEN in Asians with HLA-B1502 allele
    • Recommend testing for this allele prior to prescribing carbamazepine to individuals of Asian descent
  • Syndrome of Inappropriate ADH (Hyponatremia)
  • Very rare hepatotoxicity
  • Rashes are common (up to 5% of patients)
  • Slows cardiac conduction

 

Commons Side Effects:

 

  • Elevated GGT (not concerning unless >3x normal limit)
  • Sedation
  • Fatigue
  • Nausea
  • Dizziness

 

At higher doses:

 

  • Ataxia
  • diplopia
  • muscle incoordination
  • nystagmus

 

Carbamazepine Overdose:

 

  • Stupor
  • Coma
  • Death

 

Drugs that may increase carbamazepine levels:

 

  • Cimetidine
  • Ciprofloxacin
  • Diltiazem
  • Fluoxetine
  • Fluvoxamine
  • Doxycycline
  • Erythromycin (and other macrolide antibiotics)
  • Fluconazole
  • Grapefruit juice
  • Isoniazid (INH)
  • Ketoconazole
  • TCAs
  • Valproate
  • Warfarin
  • Norfloxacin
  • Verapamil

 

Drugs whose blood levels are decreased by carbamazepine:

 

  • Atypical antipsychotics (olanzapine, risperidone, clozapine)
  • Benzodiazepines
  • Doxycycline
  • Ethosuximide
  • Fentanyl
  • Glucocorticoids
  • Haloperidol
  • Methadone
  • Oral contraceptives
  • Phenothiazines
  • Phenytoin
  • Sertraline
  • TCAs
  • Theophylline

INFORMATION ABOUT MOOD DISORDERS

 

What Does “Mood” Mean?

 

Mood is defined as a person’s internal emotional state that is sustained over time. Mood is subjective and experienced by the person. Terms used to describe mood: Normal, Sad, Angry, Irritable, Anxious, Happy

 

What Does “Affect” Mean?

 

Affect is a term used to describe the outward expression of a mood state. In other words, an individual’s affect is visible to others. Healthcare providers obtain important information about an individual’s internal emotional experience (mood) based on their emotional expression (affect). Terms used to describe an individual’s affect: Dysphoric, Happy, Excited, Irritable, Angry, Tearful, Blunted, Euthymic, Flat, Blunted, Constricted, Restricted, Appropriate, Congruent.

 

What Are Mood Disorders?

 

Mood disorders are group of psychiatric disorders in which disturbances of mood or affect are severe and persistent enough to cause significant problems in an individual’s life. Moods by themselves are not pathological and many of us have experienced a wide range of mood states. When moods become severe and persistent enough to cause dysfunction and issues in an individual’s life, then we use the term “mood disorder.”  Mood disorders are better defined as syndromes consisting of a cluster of signs and symptoms that often “come and go” in “episodes” which persist for weeks, months, or even years. During these “episodes,” there is a significant change in the individual’s mood which may negatively impact work performance, relationships, or other important areas of functioning. The most common mood disorder is major depressive disorder (MDD), often referred to as “Unipolar depression.” Bipolar disorders are also mood disorders that differ from unipolar depression by the presence of elevated mood states called hypomania or mania.

 

What is Mania?

 

Mania is characterized by a distinct period of abnormally and persistently elevated, expansive, or irritable mood and abnormally and persistently increased goal-directed activity or energy, lasting at least 1 week and present most of the day, nearly every day (or any duration if hospitalization is necessary). During this period of elevated/expansive mood/energy, individuals may experience any combination of the following: Inflated self-esteem or grandiosity; Decreased need for sleep (e.g., feels rested after only 3 hours of sleep); More talkative than usual or pressure to keep talking; Flight of ideas or subjective experience that thoughts are racing; Distractibility (i.e., attention too easily drawn to unimportant or irrelevant external stimuli), as reported or observed; Increase in goal-directed activity (either socially, at work or school, or sexually) or psychomotor agitation (i.e., puroseless non-goal-directed activity); Excessive involvement in activities that have a high potential for painful consequences (e.g., engaging in unrestrained buying sprees, sexual indiscretions, or foolish business investments). As with any “disorder,” the mood disturbance is sufficiently severe to cause marked impairment in social or occupational functioning or to necessitate hospitalization to prevent harm to self or others, or there are psychotic features. If the mood disturbance can be attribute dto a drug, medication, or medical condition then the term “manic episode” should not be used. 

 

What is Hypomania?

 

Hypomania is a less severe form of mania and is characterized by a distinct period of abnormally and persistently elevated, expansive, or irritable mood and abnormally and persistently increased activity or energy, lasting at least 4 consecutive days and present most of the day, nearly every day with the same symptoms that characterize mania (see above). 

 

Subtypes of Bipolar Disorder:

Bipolar 1 Disorder: Manic or Mixed episode +/- Major Depressive Episode (Only manic episode required) 

Bipolar 2 Disorder: Hypomanic episode + Major Depressive Episode (both are required)

With rapid cycling: 4 or more mood episodes in a 12-month period

 

 

 

Neurobiology of Bipolar Disorder 

 

The underlying biochemical abnormalities that cause or contribute to bipolar disorder remain unclear. However, studies have suggested neurobiological differences between unipolar and bipolar depression which is further supported by the relative lack of efficacy of classic antidepressant monotherapy in the treatment and prevention of bipolar depression. Human studies have found increased concentrations of noradrenaline (norepinephrine) and dopamine (DA) and decreasedconcentrations of serotonin (5-HT) in manic patients which suggests that norepinephrine and dopamine dysregulation may play a primary role in manic symptoms. In patients with unipolar depression, both serotonin (5-HT) and norepinephrine concentrations are low. Perhaps the imbalance partially explains bipolarity? Lastly, glutamate and GABA dysregulation have been implicated in the pathophysiology of bipolar disorder. Animals studies suggest increased glutamatergic neurotransmission via NMDA receptors in manic patients. In addition, the efficacy of anticonvulsants and benzodiazepines in the treatment of bipolar disorder suggests the likelihood that glutamate and GABA systems are involved in uncertain ways. 

 

It is likely that the combination of vulnerable genetics and environmental stressors lead to intracellular changes in transcription, signal transduction, and synaptic functioning that ultimately give rise (via poorly understood mechanisms) to symptoms of bipolar disorder.

 

 

Functional Imaging Studies

 

Functional Connectivity Studies have demonstrated or suggested

 

(1) Decreased connectivity between the amygdala and anterior cingulate cortex

(2) Increased connectivity between the amygdala and the supplemental motor area

 

Functional Neuroimaging Studies have demonstrated or suggested

 

(1) Decreased size and activity in the PFC of patients with bipolar disorder—similar to that found in patients with unipolar depression.

(2) Increased gray matter volume in bipolar patients after 4 weeks of lithium treatment (Note: Valproic acid (depakote) has not been shown to have the same effect.

(3) Amygdala are larger and more active in the bipolar patients.

(4) Bipolar disorder may be the result of abnormal interactions between the PFC and subcortical regions such as the amygdala—an abnormality not usually seen with unipolar depression.

 

References:

  1. Cooper, J. R., Bloom, F. E., & Roth, R. H. (2003). The biochemical basis of neuropharmacology (8th ed.). New York, NY, US: Oxford University Press.
  2. Iversen, L. L., Iversen, S. D., Bloom, F. E., & Roth, R. H. (2009). Introduction to neuropsychopharmacology. Oxford: Oxford University Press.
  3. Puzantian, T., & Carlat, D. J. (2016). Medication fact book: for psychiatric practice. Newburyport, MA: Carlat Publishing, LLC.
  4. J. Ferrando, J. L. Levenson, & J. A. Owen (Eds.), Clinical manual of psychopharmacology in the medically ill(pp. 3-38). Arlington, VA, US: American Psychiatric Publishing, Inc.
  5. Schatzberg, A. F., & DeBattista, C. (2015). Manual of clinical psychopharmacology. Washington, DC: American Psychiatric Publishing.
  6. Schatzberg, A. F., & Nemeroff, C. B. (2017). The American Psychiatric Association Publishing textbook of psychopharmacology. Arlington, VA: American Psychiatric Association Publishing.
  7. Stahl, S. M. (2014). Stahl’s essential psychopharmacology: Prescriber’s guide (5th ed.). New York, NY, US: Cambridge University Press.
  8. Stahl, S. M. (2013). Stahl’s essential psychopharmacology: Neuroscientific basis and practical applications (4th ed.). New York, NY, US: Cambridge University Press.
  9. Whalen, K., Finkel, R., & Panavelil, T. A. (2015). Lippincotts illustrated reviews: pharmacology. Philadelphia, PA: Wolters Kluwer.

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