Drugs for Bipolar Disorder

Question 1

Characteristics of depressive phase of bipolar disorder

Answer 1

Depressed mood, diurnal variation, sleep disturbance, anxiety, and sometimes psychotic symptoms

Question 2

Bipolar I

Answer 2

Mania and depressive episodes

Question 3

Bipolar II

Answer 3

Hypomania and depressive epidodes

Question 4

Lithium
Use
Mechanism
Adverse rxns
Precautions

Answer 4

• Use – 1st line for bipolar (used in acute phase and to prevent recurrence). Also used for MDD and w/ antipsychotics in schizoaffective disorders.
• Mechanism – Inhibits 2 phosphatase enzymes involved in inositol recycling → low IP3. Li competes w/ Na, K, Ca, and Mg → altered gene expression involved in neuroplasticity / mood stabilization.
• Adverse rxns – very common (75% of pxs)
• CNS: fine tremor, ↓ libido, anorexia, drowsiness, confusion
• CV: ECG abnormalities, bradycardia
• GI: xerostomia, altered sense of taste, NVD; reduced if taken with food
• UG: POLYURIA (with polydipsia; disappears after a few weeks)
• Hypothyroidism → goiter (4%), CNS depression
• Edema, weight gain (30%)
• Leukocytosis
• Precautions – pregnancy risk D, renal insufficiency, diuretics increase serum [Li]

Question 5

Carbamazepine
Type of drug
Mechanism
Adverse rxns

Answer 5

Antiseizure med. May be combined w/ lithium.
Blocks Na channels.
May cause dermatologic side effects such as Stevens-Johnson.

Question 6

Lamotrigine
Type of drug
Use

Answer 6

Antiseizure drug.

Delays time to occurrence of mood disorders in stabilized pxs. Only good for maintenance.

Question 7

Valproic Acid
Type of drug
Use
Mechanism

Answer 7

Antiseizure med.
1st line for treating bipolar. Similar efficacy to lithium.
Increases GABA function.