Bipolar Flashcards
what is bipolar disorder?
characterized by recurrent episodes of mania and depression
- 3-4% of populations
- the periods of mania and/or depression alternate with intervening well periods
classification of bipolar disorders:
- bipolar I: “one of more manic or mixed episodes and one or more major depressive episodes” Normal functioning is greatly impaired and the patient may be hospitalized
- bipolar II: “one or more major depressive episodes accompanied by at least one hypomanic episode.” A hypomanic episode is similar to a manic episode, but isn’t as severe and doesn’t last as long
when is a patient likely to undergo lifetime treatment with mood stabilizing drugs?
a patient who experiences at least tow episodes of mania
DSM-IV criteria for mania
period of abnormally intense excitement last at least one week with at least 3 of the following:
-inflated self-esteem
-decreased need for sleep
-talkativeness
-racing thoughts
-easily distracted
-increased motivation
-unusual interest in activities that can lead to painful results
(basically they are more child-like, except the sleep thing)
less sever form of bipolar disorder which doesn’t reach the threshold for BP1 or 2
-may be a precursor (1/3 are eventually diagnosed with BP)
Cyclothymic disorder
category for bipolar disorders which don’t fit the criteria for BP1, 2 or cyclothymic disorder
Bipolar disorder not otherwise defined ((NED?)
what are the classes of bipolar treatment drugs?
- mood stabilizers
- anti-epileptic drugs (AED’s)
- atypical atipsychotics
- antidepressant drugs
what is the most popular mood stabilizers
lithium, effective in 60-80% of bipolar
-in normal ppl it basically has no effect
in the 1920’s it was used as a sedative-hypnotic compound (both calming and sleep inducing effects) and used as an anticonvulsant drug
lithium
pharmacokinetics of Lithium
- When administered orally Lithium is absorbed rapidly and completely.
• Within 3 hours peak blood levels are reached, and complete absorption occurs by 8 hours.
• Its efficacy is directly correlated to its level in the blood.
• It does cross the blood brain barrier; and it is not recommended during pregnancy
-narrow therapeutic range (2-3), monitor plasma levels
structure of lithium upon excretion
- lithium is not metabolized before excretion, thus unchanged
- half of an oral dose is excreted within 18-24 hours
- long half life
how long does it take for lithium therapy to become effective?
1-2 weeks
side effects of lithium
- related to plasma concentration
- Toxic effects involve the GI tract, kidneys, CV system, skin and nervous system
- long term the gyroid may become enlarged, 30% pts become obese
- pts often become dehydrated
- Neurological: lethargy, impaired concentration and dizziness
drug interactions with lithium
- NSAID’s reduce renal excretion of Lithium
- indomethacin: strong effect
- Ibuprofen and naproxed: moderate effect
- aspirin and sulindac: weak effect
txt of lithium overdose
no specific antidote, but can:
- sodium containing fluids to flush it out
- hemodialysis
- gastic lavage (pump stomach if Li is in there)
- diuretic therapy
- antiepileptic medications
big problem associated with lithium use
- noncompliance (up to 50% of pts)
- comorbidity: more than 55% of bipolar patients have a history of substance abuse (esp alcohol)
Lithium is often used in combination therapy with what other drugs?
-alone is only effective in 50-60% of cases
- lithium+anticonvulsant
- lithium + atypical antipsychotics
- lithium + other drugs
what three anticonvulsants have been shown to be effective in the treatment of bipolar disorder?
- Carbamazepine
- Lamotrigine
- Valprotic Acid
- Effective for acute mania/mixed episodes and maintenance
- Superior to Li+ in controlling rapid cycling bipolar disorder.
- currently regarded as a “second line” treatment for mania, usually used in combination with Li+.
- Broader spectrum of activity- used in patients with non-classical bipolar disorder.
Carbamazepine
adverse effects of Carbamazepine
- sedation
- upset stomach
- visual disturbances
- cognitive functioning (limited)
- white blood cell reduction, anemia (blood should be analyzed periodically)
what drug produces neural tube defect in 1% of offspring?
carbamazepine
- Effective in acute mania/mixed episodes, rapid cyclers and for maintenance.
- More effective than Li+ in patients with comorbid depression and/or cyclothymia.
- augments post-synaptic action of GABA
- Intravenous administration overcomes the 3 to 10 day waiting period for oral administration to take effect (also no need for sedatives to control mania before drug takes effect.)
Valproic Acid
- Approved in 2003 by FDA for Bipolar I disorder
- Also effective for personality disorders, schizoaffective disorder, and PTSD.
- Inhibits neuronal excitability by inhibiting release of glutamate
- many drug interactions
- can cause (fatal) rash
Lamotrigine
- NotformallyapprovedbyFDAforuseinbipolar treatment and limited controlled studies have shown it has no clinical efficacy.
- PfizerandWarner-LambertsuedbyStatesAttorneys General for deceptive marketing for bipolar treatment
- Veryfewdruginteractions,excretedunchanged.
- DoesnotalterLi+activity
- Unstudiedinpregnant/breast-feedingwomen tolerable side effects
Gabapentin
