Bipolar Depression Flashcards
What is the most common tx for bipolar depression?
- Mood stabilizers
- The most prescribed is lithium..other tx have become more popular.
- Lithium (Eskalith, Lithobid, and Lithonate) can also be given in combination with certain antipsychotics to tx psychosis-induced mania.
- Really a continuum of severity: Monopolar Depression-> Bipolar Depression (inpatient)-> Psychosis (inpatient)
Monopolar Depression
- These pts will be on psych floor inpatient b/c of suicidal ideations.
- is usually tx as an outpt
Bipolar Depression
- it has components of MD in addition to psychosis
- Mania tends to be a psychotic symptom, but the mixture of the 2 components..usually have suicidal ideation and homicidal ideations
Cutters tend to be in the middle caegory
cycles b/w mania and depresssion
goal of tx..you want to take out the highs and lows..we do this via mood stabilizers
mood stabilizers do this by decreasing neuronal activity by blocking ion channels…particularly, CATION channels (Na, K, Ca, etc)
Several problems with this..very rarely can you tx bipolar by meds..they feel “blah” and they know this is not how they are supposed to feel..they hate it
Drinking is highly co-morbid with depression
9 out of 10, you will give these MOOD STABILIZERS WITH A SECOND GENERATION ANTIPSYCHOTIC
drugs used to tx bipolar d/o:
- lithium
- lamotrigine
- depakote
- tegretol
- carbamazepine
- olanzapine
Characteristically, lithium (Li+):
Tends to block Na+ channels
orally admin and absorbed, although its passage into the CNS is slow (its kinetics are similar to those of the sodium (Na+) ion)
long acting ( t1/2=24hrs)
excreted 95% unchanged in urine; does not bind plasma proteins
excreted in human milk, and therefore, women on lithium should not breast feed
ineffective in approx 30% of the pt who take it
MOA of Lithium
have not been firmly est
inhibits nerve metabolism, alters reuptake of serotonin, NE, and dopamine, and decreases release
decreases protein kinases in brain tissue such as PKC and directly affects neuronal inositol levels by directly inhibiting inositol monophosphatase
A/E of Lithium
Frequently cause problems with compliance
a/e from a therapeutic dose are qualitatively similar to toxic effects
Problems with the GI tract- can be an indication of toxicity or simply peak absorption, nausea, diarrhea
Drowsiness
Polyuria- 80% of filtered Li+ is reabsorbed by the proximal renal tubles
Dry mouth and thirst
Acquired neprogenic diabetes can occur in pts maintained at therapeutic plasma concentrations of lithium, because:
- inhibition of AVP-mediated water reabsorption in the collecting duct
- attenuated reabsorption of Na+ in the PCT
weight gain
insomnia
a small number of pt develop a benighn, diffuse, nontender thyroid enlargement, suggestive of thyroid dysfunction; however, most pts remain euthyroid and hypothyroidism is rare. In pts who develop goiter, d/c of lithium or tx with thyroid hormone results in shrinkage of the gland
a benign, sustained increase in circulating polymorphonuclear leukocytes occurs during chronic tx and is reversed within a week of terminating tx
What are the effects of acute lithium intoxication?
can be seen even at therapeutic serum concentrations
75-90% of pts tx with lithium will experience a toxic event at some point during tx
toxicities have been shoen to affect the CNS, heart, GI tract, and kidneys
s/s:
- AMS
- Vomiting
- Profuse diarrhea
- Coarse tremor atxia
- Coma
- Convulsions- in non-epileptic pt at therapeutic doses
lithium toxicity, neuroleptic malignant syndrome (NMS) and serotonin syndrome can all present with a number of symptoms that are similar; one factor that may distinguish lithium toxicity from NMS or serotonin syndrome is hyperthermia..
PT WITH LITHIUM TOXICITY ARE NOT USUALLY FEBRILE**
Drug interactions with lithium:
- Diuretics seem to be the most problematic interaction because most diuretics with increase Na+ excretion and indirectly decrease Li+ excretion..this leads to increased or toxic levels of lithium
- increase excretion-osmotic diuretics and acetazolamide
- decrease excretion- the thiazides and loop diuretics that deplete Na+ - nonsteroidal antiinflammatory agents such as indomethacin, naproxen and ibuprofen may diminish clearance and increase reabsorption of lithium, leading to toxicity
Lamotrigine (Lamictal)
is the first drug given FDA approval for lont-term prophylactic tx of bipolar d/o without an indication of acute mania
it is particularly effective against bipolar depression with minimal risk of inducing mania
valproic acid (depakote) or valproate -anticonvulsants-
is FDA approved for mania and is extensively used off-label for long-term prophylactic tx of bipolar pts
has less s/e than other drugs
DRUG OF CHOICE
Carbamazepine
is sometimes used for tx of resistant bipolar d/o and remains under investigaton.
The antipsychotic olanzapine (Zyprexa) is also used
