Mood Stabilizers

Question 1

Which AEDs are most commonly used for mood stabilization?

Answer 1

Valproic acid and Lamotrigine.

Question 2

What is the effect if antidepressants are used in bipolar disorder?

Answer 2

They will precipitate a manic episode.

Question 3

What is the mechanism of action for lithium?

Answer 3

The MOA is not fully understood; it likely works through a number of different mechanisms.

Question 4

What are some characteristics of lithium?

Answer 4

It is a very old and simple drug; it has a VERY narrow therapeutic index.

Question 5

What is the primary dose-related ADR that occurs with lithium use?

Answer 5

Intention tremor.

Question 6

What ADRs occur as a result of ADH inhibition?

Answer 6

Polydipsia, polyuria, and diarrhea.

Question 7

What percent of patients on lithium acquire hypothyroidism?

Answer 7

20%: it tends to be irreversible and develops with chronic use.

Question 8

What cardiovascular ADRs can occur with lithium use?

Answer 8

Sick sinus syndrome and SA node block.

Question 9

What blood condition can occur with lithium use?

Answer 9

Mild leukocytosis (without a shift to the left); usually asymptomatic.

Question 10

What ADR occurs as a result of increased PTH?

Answer 10

Hypercalcemia.

Question 11

What is the therapeutic dose range of lithium?

Answer 11

0.5-1.2

Question 12

What are the symptoms of lithium toxicity?

Answer 12

Dizziness, vomiting, severe diarrhea, delirium, cardiac arrhythmia, coma, renal failure, and death.

Question 13

How is lithium excreted?

Answer 13

Excretion s entirely renal; lithium clearance is proportional to creatine clearance (kidney function).

Question 14

Which drugs have DDIs, with the potential for causing lithium toxicity?

Answer 14

NSAIDs (concerning with large doses); thiazide diuretics (even at small doses); ACE inhibitors; ARBs; and calcium-channel blockers.

Question 15

How do these drugs cause lithium toxicity?

Answer 15

They increase reabsorption and decrease excretion of lithium at the distal renal tubule.

Question 16

How does lithium toxicity lead to further lithium retention?

Answer 16

Sodium and lithium get absorbed together; lithium toxicity causes dehydration and sodium retention. Thus lithium is further reabsorbed.

Question 17

What are the monitoring requirements for lithium?

Answer 17

Lithium levels must be monitored routinely (8-12 hours after the last dose); thyroid and kidney function are also monitored; TSH levels should be checked at least once per year.

Question 18

What are the therapeutic uses of lithium?

Answer 18

It is an effective treatment for mania and depressive episodes; it has also been shown to reduce the risk of suicide, and have a neuroprotective effect.