Mood Stabilizers

Question 1

Lithium

Answer 1

Uses various signal transduction sites beyond neurotransmitters - G proteins, gene expn, 2nd messengers

Treats:

• Manic episodes, prevents recurrence
• Depressive phase of bipolar disorder
• Sometimes used as augmentation agent for depressive illnesses

Question 2

What organ exclusively excretes Lithium? What does it excrete it with?

Answer 2

Kidney, with Na+

Question 3

What condition poses a risk of lithium toxicity?

Answer 3

Hyponatremia

Question 4

What should patients avoid when taking Lithium?

Answer 4

Becoming dehydrated (during exercise), Na+ depleting diuretics, low Na+ diets, NSAIDs b/c of their effect on renal prostaglandin synthesis and Na+ excretion

Question 5

Lithium: Wide or narrow therapeutic index?

Answer 5

Narrow

Question 6

What must you check before starting a patient on Li?

Answer 6

Renal function - BUN and creatinine, Baseline thyroid function, Urine pregnancy test, EKG, baseline blood count

Question 7

Side FX of Li that causes a tricuspid valve defect in 1st trimester of pregnancy?

Answer 7

Ebstein’s anomaly

Question 8

Tremor, nausea and diarrhea, nephrogenic diabetes insipidus, hypothyroidism, weight gain, alopecia, interference of conduction in SA node, Ebstein’s anomaly, leukocytosis

Answer 8

Side FX of lithium

Question 9

Avoid prescribing Li to patients with what medical conditions?

Answer 9

• Cardiac conduction problems

- Impaired renal function

Question 10

Coarse tremor, vomiting, ataxia, dysarthria, confusion, seizures

Answer 10

Symptoms of Li toxicity

Question 11

Are anticonvulsants effective as mood stabilizers?

Answer 11

Not all of them - depends on mechanism of action

Question 12

Valproic Acid/Divalproex

Depakote

Answer 12

Anticonvulsant that inhibits voltage sensitive Na+ channels, increases action of GABA, regulates downstream signal cascades

Effective in acute phase of mania

Question 13

Metabolism of Valproic acid/Divalproex (Depakote)

Answer 13

Hepatic - inhibits P450 enzymes

Question 14

Side FX of Valproic Acid/Divalproex (Depakote)

What types of patients should you not use this drug with?

Answer 14

Sedation, weight gain, alopecia, tremor

Pts with clotting abnormalities- causes thrombocytopenia

Pts with liver disease - causes hepatotoxicity

Question 15

Lamotrigine (Lamictal)

Answer 15

Anticonvulsant, used off label for depressed phase, not appropriate for mania

Inhibits voltage-sensitive Na+ channels, inhibits glutamate release, blocks Ca2+ channels

Question 16

Metabolism of Lamotrigine (Lamictal)

Combination with what drugs affect its levels?

Answer 16

Hepatic - levels increased by valproic acid and decreased by carbamazepine

Question 17

Side FX of Lamotrigine (Lamictal)

Answer 17

Relatively few - some sedation

1/1000 risk of Stevens-Johnson sydrome and toxic epidermal necrolysis

Question 18

Carbamazepine (Tegretol) and Oxcarbamazepine (Tripletal)

Which one is effective in treating mania?

Answer 18

Anticonvulsants

Blocks voltage sensitive Na+ channels, enhances GABA function

Carbamazepine for acute mania

Question 19

Metabolism of Carbamazepine (Tegretol) and Oxcarbamazepine (Tripletal)

Which induces hepatic enzymes, increasing its own metabolism as well as metabolism of other drugs? (TEST QUESTION)

Answer 19

Hepatic

Carbamazepine/Tegretol

Question 20

Side FX of Carbamazepine (Tegretol)

Answer 20

Sedation, rash progression to Stevens-Johnson, SIADH (hyponatremia), neural tube defects, decreases effectiveness of oral contraceptives

Question 21

Side FX of Oxcarbamazepine (Tripletal)

Answer 21

Sedation, higher risk of SIADH