Mood Stabilizers Flashcards
common mood stabilizers
lithium
valproic acid
carbamazepine
lamotrigine
less common mood stabilizers
delayed onset, may help w/ manic states of bipolar disorder
risperidone olanzapine quetiapine ziprasidone aripiprazole
^all second generation, atypical antipsychotics (likely metabolic side effects)
Lithium MOA
Reduces Na+ transport (Li+ mimics Na+) and inhibits myo-inositol-1-phosphatase inhibiting inositol recycling
- ->membrane stabilization (dec ion flux = dec APs)
- ->CNS depression
may take days/weeks for full effect
acute sx usually req addnl therapy (Benzos, antipsychotics)
Lithium is standard therapy for
mania and bipolar
Serum lithium levels are best monitored once the medication has reached a steady state, which is usually after _____ of consecutive dosing.
Serum lithium levels are best monitored once the medication has reached a steady state, which is usually after 4-5 DAYS of consecutive dosing.
lithium side effects
initial transient vs. initial persistent
initial/transient: nausea, diarrhea, fatigue
initial/persistent: tremor, weight gain, polyuria, polydipsia
Lithium is cleared intact primarily through the ______. Ramifications?
Lithium is cleared intact primarily through the KIDNEYS.
DRIVES BODY TO DILUTE BLOOD
-bc may cause inc blood osmolarity (like Na+) causing
increased ADH release and thirst, but Li+ blocks ADH-receptors in the collecting duct, causing a diabetes insipidus-like state (polyuria)
lithium adverse effects
confusion/ataxia (signs of OD)
-may progress to seizures
renal toxicity
thyroid disturbances (mild hypothyroidism)
others: skin rxns, leukocytosis, arrhythmia
baseline monitoring tests for lithium
creatinine, BUN (nephrotoxic)
thyroid (hypothyroidism)
electrolytes
ECG
Drugs that can increase lithium serum levels, and thus increase the risk for toxicity, include…
ACE inhibitors (captopril, lisinopril)
thiazide diuretics (hydrochlorothiazide, chlorthalidone)
NSAIDs ( ibuprofen, naproxen)
Medications that are known to decrease lithium levels include…
K+ sparing diuretics (amiloride)
treats diabetes insipidus effects
anticonvulsants as mood stabilizers
possible MOAs
modulation of voltage-dependent ion channels involved in propogating AP
enhancement of inhibitory activity (GABA)
inhibition of excitatory activity
(glutamate, aspartate)
What are the risks of anticonvulsants?
CNS side effects (sedation, dizziness, ataxia)
potential inc risk for suicidality
drug interactions
valproic acid
Used as a lithium alternative with FASTER onset; acts to inc GABA causing CNS depression
FDA indication for mania and bipolar
narrow therapeutic window
valproic acid adverse effects
Similar to Li
- Tremor, sedation, weight gain, nausea, diarrhea;
Others
- alopecia
- teratogenicity: neural tube defects (pregnancy, category D)
- inc in LFTs, can cause fatal hepatotoxicity.
Rarely causes
-platelet dysfunction, PANCREATITIS, agranulocytosis
valproic acid requires monitoring of …
valproic acid requires monitoring of liver function and platelet count
Carbamazepine
Used if patient is intolerant to both lithium and valproate
MOA: stabilizes Na+-channels, reducing ion flow and AP propagation causing CNS depression
Carbamazepine side effects
- bone marrow suppression (aplastic anemia), need CBC monitoring
- produces active, toxic metabolite (10,11-epoxide)
- HLA-based predisposition (asian) –> severe rashes
- Potent CYP450 inducer (requires titration of dose over time, may cause DRUG INTERACTIONS)
- hyponatremia, BC drug enhances ADH release (SIADH) causing fluid retention and dilution of systemic Na+
Oxcarbazepine
Carbamazepine derivative drug with less CYP450 induction and no production of toxic metabolite
Fewer overall symptoms except for risk of hyponatremia (poss a bit higher)
Lamotrigene
MOA/side effects?
Inhibits excitatory glutamatergic activity
Side Effects:
- Dizziness, ataxia, somnolence, nystagmus, blurred vision.
- Risk of severe rash (can lead to Stevens-Johnson Syndrome), DOSE TRITIATION NEEDED
How do anticonvulsants interact with other drugs?
Many anticonvulsant medications undergo extensive hepatic metabolism. They are often substrates as well as inducers of the CYP450 system
Carbamazepine –> potent inducer of this system and will commonly lower serum levels of other substances that are metabolized via similar pathways
