Mood stabilizers Flashcards
(197 cards)
what is considered the gold standard mood stabilizer for bipolar disorder
lithium
which has a more rapid anti-manic effect, lithium or valproate
valproate (therapeutic benefit seen in 3-5 days)
list medications that fall under the “mood stabilizers and anticonvulsants” label
lithium
valproate
carbamazepine
gabapentin
lamotrigine
levetiracetam
phenytoin
pregabalin
oxcarbazepine
what is the strictest definition of mood stabilizer
an agent that treats and prevents acute mania and depression
what is the broadest definition of mood stabilizer
an agent that is effective at either treating or preventing mania or in treating or preventing depression, and does not exacerbate symptoms
how long do mood stabilizers generally take for a good response
1-2 weeks
some initial effects can take place within 48 hours
why are antiepileptics used to treat bipolar disorders
bipolar disorder and epilepsy share common features including an EPISODIC course of illness and KINDLING phenomena
the AMYGDALA plays role in both disorders as well
however epilepsy and bipolar disorders are two distinct diseases
what is the mechanism of action of most mood stabilizers
most have multiple MOAs
include modulation of GABA-ergic and glutamatergic neurotransmission and alteration of VOLTAGE GATED ION CHANNELS or intracellular signalling pathways
what is the mechanism of action of lithium
“unknown and complex”
alters SODIUM TRANSPORT across cell membranes in nerve and muscle cells
alters metabolism of neurotransmitters including catecholamines and serotonin –> may alter intracellular signalling through actions on second messenger systems
specifically–> INHIBITS INOSITOL MONOPHOSPHATASE–> possibly affecting neurotransmission via phasphatidyl inositol second messenger system
also REDUCED PROTEIN KINASE C activity–> possibly affecting genomic expression associated with neurotransmission
how might lithium provide neuroprotective effects (what mechanism of action)
–increasing glutamate clearance
–inhibiting apoptotic glycogen synthase kinase activity
–increasing levels of antiapoptotic protein Bcl-2
–enhancing the expression of neurotropic factors (including brain derived neurotropic factor)
how might lithium affect genomic expression associated with neurotransmission
possibly by reducing protein kinase C activity
indications for lithium therapy
manic episodes in bipolar illness
maintenance patients with bipolar disorder
bipolar depression
MDD (adjunctive)
onset of action of lithium
1-3 weeks
how do you titrate lithium in the acute setting
start 300mg 2-3x/day
rapidly increase to 900-1200mg per day
(“dr lam slams it in after one day of 600mg)
THEN DO LEVELS
how do you titrate lithium in the outpatient setting
for low mood–> 150mg po daily for 1 week, then increase to 300mg po daily
then measure levels
what are the benefits to converting lithium from split dosing to once daily dosing
ideally daily at HS
less kidney exposure to lithium, possibly less CKD and side effects overall
how do you change the dose of lithium if going from divided doses to once daily dose
once daily dose is 20% LOWER than in divided doses–> this is because kidneys filter lithium more slowly while u are sleeping
i.e if was on 1500mg total daily dose in divided doses, then nighttime dose would be 1200mg
what is the typical adult target range dose for lithium
300-2400mg per day
what is the typical adolescent dose range for lithium
300-1800mg per day
in what forms does lithium come
capsules (carbonate)
liquid (citrate)
what baseline monitoring needs to be done for lithium
CBC/diff
electrolytes
creatinine/BUN
TSH, Ca, consider PTH
weight
beta-hcg in all women
ECG if over 40 or cardiac hx
what investigations should be ordered during maintenance phase of lithium therapy for monitoring
CBC.diff
electrolytes
creatinine, BUN
TSH
lithium level (minimum 5 days after dose change)
weight q6 months
calcium
PTH
how frequently should you measure calcium and PTH in lithium maintenance monitoring
calcium q2years
PTH ?q5 years and if indicated
when should you draw lithium levels
12 hours post dose so a “trough” level