Drug therapy of bipolar

Question 1

Differentiate bipolar I from bipolar II

Answer 1

Bipolar I: episodes of mania and depression

Bipolar II: episodes of hypomania and depression

Question 2

Antidepressant drugs may precipitate _____ and should not be given to patients with bipolar disorder

Answer 2

mania

Question 3

List the three categories of pharmacotherapy for bipolar disorder

Answer 3

Lithium
Atypical antipsychotics
Antiseizure agents

Question 4

In addition to being used to treat bipolar disorder, lithium can also be used in _____ disorder and can be combined with atipsychotic agents in _______ disorders

Answer 4

major depressive disorder

schizoaffective disorder

Question 5

Describe the mechanism of action of lithium

Answer 5

Complex mechanism, inhibits several enzymes and is known to inhibit two phosphatase enzymes involved in inositol recycling, leading to depletion of substrate for IP3 production.
Electrolytes, neurotransmitters, and 2nd messengers are all affected; Li+ competes with Na+, K+, Ca++, and Mg++ at binding sites, initiating intracellular changes and altered expression of genes implicated in long-term neuroplastic events that may underlie long-term mood stabilization

Question 6

Describe the adverse effects seen with lithium therapy

Answer 6

CNS: tremor, decreased libido, anorexia, confusion
CV: ECG changes, bradycardia
GI: xerostomia, NVD
UG: polyuria
Decreased thyroid function
Edema and weight gain
Leukocytosis

Question 7

Describe precautions with lithium therapy

Answer 7

Narrow therapeutic window
Greater toxicity with renal failure, diuretics
Pregnancy Risk D

Question 8

List atypical antipsychotics used to treat bipolar disorder

Answer 8

Aripiprazole, olanzapine, quetiapine, risperidone, ziprasidone

Question 9

Valproic acid

Answer 9

Antiseizure agent, first-line TX for bipolar disorder, efficacy similar to lithium during early TX period; ↑ GABA function

Question 10

Carbamazepine

Answer 10

Antiseizure agent, Na+ channel blocker may be used alone or in combination with lithium; or rarely, valproic acid

Question 11

Oxcarbazepine

Answer 11

Antiseizure agent, Na+ channel blocker chemically related to carbamazepine

Question 12

Gabapentin

Answer 12

Antiseizure drug, structural analogue of GABA, but does not bind to GABA sites; well-tolerated; efficacy?

Question 13

Topiramate

Answer 13

Antiseizure drug, MOA involves Na+ channels, GABAA receptors, glutamate receptors, carbonic anhydrase inhibition; efficacy?

Question 14

Lamotrigine

Answer 14

Antiseizure drug, exact MOA unknown (Na+ channel blocker?), delays the time to occurrence of mood disorders in stabilized patients, clinical findings are more robust for depression

Question 15

Asenapine

Answer 15

Atypical agent a for acute manic phase of bipolar I and as an antipsychotic agent; has high affinity for numerous 5-HT, NE, DA, and histamine receptors