Mood Stabilizers

Question 1

Lithium MOA & levels

Answer 1

Exact mechanism of action is unknown (generally stimulates inhibitory neurotransmission and inhibits excitatory transmission)

reduces excitatory (dopamine and glutamate) but increases inhibitory (GABA) neurotransmission;

.6-1.2

Half life is 24 hours, steady state is achieved about 5 days

Question 2

Lithium (lab monitoring)

Answer 2

• Urinalysis, BUN, creatinine q 2-3months for 6 months, then q 6-12 months thereafter
• Thyroid dysfunction - TSH 1-2x for first 6 months, q 6-12 months thereafter
• Hypercalcemia - calcium q12 months
• obtain a level within 2 weeks of a dose increase
  -PREGNANCY test

Question 3

Lithium (side effects)

Answer 3

Nausea (10-20% of patients)

Diarrhea

Polyuria & polydipsia (up to 70% of patients)

Tremor (up to 25% of patients)

Sexual dysfunction

Weight gain

Cognitive impairment

Increased risk of serotonin syndrome with SSRI/SNRIs

Question 4

Lithium (hydration)

Answer 4

Increased water intake will decrease lithium level, vice versa
Increased salt intake will decrease lithium level, vice versa

Dehydration leads to risk of toxicity as level rises

Question 5

Valproic Acid (Depakote) MOA & Level

Answer 5

• May inhibit voltage-sensitive sodium channels
• May boost the actions of the neurotransmitter GABA

80-125 for acute mania, 50-100 for maintenance

For acute mania, dosing is weight based (15-20mg per kg)

Half life is 24 hours, steady state is achieved about 4-5 days

Question 6

Valproic Acid (side effects)

Answer 6

Weight gain/insulin resistance
Nausea, vomiting
Hair loss
Sedation
Tremor
PCOS, amenorrhea, birth defect

Rarely, hepatic failure, thrombocytopenia, pancreatitis

Question 7

Valproic Acid (blood monitoring)

Answer 7

Prior to starting:
- LFTs, CBC, pregnancy test

During treatment:

• LFTs: frequently during first 6 months, then q6-12 months
• CBC/platelets: periodically

Question 8

Carbamazepine (Tegretol) MOA

Answer 8

may block voltage-sensitive sodium channels and inhibit release of glutamate

Not often prescribed due to how many drug-drug interactions

Question 9

Lamotrigine (Lamictal) MOA

Answer 9

may reduce the release of excitatory glutamate

Effective for bipolar depression- treatment and prevention, less effective in preventing mania, does not treat active mania or hypomania, does not treat unipolar depression