Bipolar Disorder Medications Flashcards
What is the one treatment regimen for bipolar disorder everyone agrees on?
Do NOT treat bipolar depression with antidepressants ONLY- the anti-depressant may flip them into a manic episode
Always treat with both an antidepressant and a mood stabilizer
Which is the first line medication for bipolar disorder?
Lithium
Is lithium used for bipolar mania or depression?
both
How does lithium affect suicide tendencies?
Lithium is one of the few drugs that reduces the risks of suicide in patients with bipolar I disorder (and bipolar II as well as major depression)
What is the onset of lithium?
Delayed- takes 2-3 weeks for full therapeutic effect
How does lithium affect 5HT?
Increases the effect of 5HT
How does lithium affect turnover of NE and DA?
Decreases turnover
How does lithium affect acetylcholine levels?
Increases ACh synthesis
How can we guess the ion transport of Li?
Similar to Na+
Describe the blood protein binding of lithium?
THere is none – unique
Describe the therapeutic window of lithium
Super narrow
How is lithium excreted?
Entirely renally
All DDI involve the kidney
What types of drugs decrease serum lithium levels?
Drugs that act at the proximal tubules- acetazolamide, mannitol
Also: aminophylline, theophylline, caffeine, pregnancy..
What type of drugs do not affect lithium serum levels?
Loop diuretics: furosemide
What type of drugs increase lithium serum levels?
Thiazides, potassium sparing diuretics, ACE inhibitors, angiotensin II
Also: dehydration, renal impairment, advanced age, sodium depletion (body increases reabsorption of Na+)
What’s a common endocrine side effect of lithium?
Hypothyroidism- important because patients can appear depressed.
TSH levels should be checked once/twice per year
Name three neurologic side effects of lithium
Fine tremor, decreased concentration and sedation
List symptoms of mild Li+ toxicity
GI symptoms: nausea, vomiting, diarrhea
State of Consciousness: drowsy/lethargic
Neuro: weakness, coarse hand tremor
List symptoms of moderate Li+ toxicity
Confusion
Myoclonic twitches, dysarthria, ataxia, nystagmus
ECG changes
List symptoms of severe Li+ toxicity
Grossly impaired consciousness/coma
Increased deep tendon reflex and seizure
Syncope
What is the treatment for Li+ toxicity?
Mild: stop treatment and wait for levels to come down
Moderate: hold off on treatment, maybe provide some supportive care
Severe: dialysis
What are a few labs that need to be monitored/checked while administering lithium?
TSH levels
Renal function
BMI
Lithium levels
Pregnancy, while starting
Name three mood stabilizers used in the treatment of bipolar disorder
Valproic acid/Depakote
Carbamezepine (Tegretol)
Lamotragine
What is the MOA of valproic acid?
Unclear
What is the absorption of depakote? How does it travel through blood?
100% absorbed
90% protein bound
What is the half-life of depakote?
12 hours (relatively short)
Name 3 major DDI of depakote
1) Displaces other drugs from protein
2) Inhibits hepatic metabolism
3) Inhibits metabolism of other convulsants –> risk of toxicity
Name major side effects of depakote (valproic acid)
GI, tremor, sedation, weight gain
also..ataxia, increased ammonia, headaches
Patient blood levels of what must be routinely checked for at higher levels of valproic acid treatment?
Platelets- check for thrombocytopenia
What labs need to be routinely checked when on valproic acid/depakote?
LFTs
Platelet count
Weight (BMI)
Valproic acid level
Pregnancy test before starting
Do we have to be concerned about carpamezapine drug-drug interactions?
YES- CYP450 inducer ( slows down metabolism of other drugs)
alos AUTOINDUCES its own metabolism
List unique side effects of carpamezapine (other than dizziness, sedation and nausea)
Neuro: ataxia, diplopia, tremor…
SJS, aplastic anemia, agranulocytosis
Which is the only mood stabilizer drug that we have to worry about knocking other drugs off of protein in the blood (due to high protein binding?)
Valproic acid/depakote
WHat is the metabolism of lamotrigine?
Glucuronidation
How does valproic acid/depokote affect lamotrigine levels?
Increases! Lamotrigine levels may double
B/C depakote inhibits UDP-glucuronidation, which is responsible for the metabolism of lamotrigine
How do oral contraceptives affect lamotrigene levels?
Cut them in half
How does carpamezepine affect lamotrigene levels?
cuts in in half
Why is the rash symptom of lamotrigene so annoying?
Because there is no way of differentiating between rash and early SJS
When does SJS occur when taking lamotrigene?
Within the first 8 weeks- unless another medication is added that may change the pharmacology of the drug
When are second generation anti-psychotics used in the treatment of bipolar disorder?
Used in combo with mood stabilizers for acute mania
SGA + Lithium or SGA + depakote
Exposure to lithium in the first trimester is associate with what teratogenic defect?
Ebstein’s anomaly
–general risk is actually pretty low…
What type of birth defects are associated with the mood stabilizers?
neural tube defects
Lamotrigine carries the lowest risk- maybe risk of cleft palate
Should you use lamotrigine to treat a manic bipolar episode?
NO
Only used for maintenance therapy
How are antidepressants used in the treatment of a manic episode of bipolar disorder?
They are not used
How are benzodiazepines used in the treatment in a manic bipolar episode?
Adjunct therapy
How is the maintenance of bipolar disorder treated?
Use whatever worked for the acute episode
Is carpamezepine used for the treatment of bipolar depression?
No- only treats mild acute manic episode or hypomania
Are FGAs used in the treatment of bipolar depression?
No- antipsychotics are really only used in the treatment of the manic phases
Which drug may be used to treat acute manic episodes, maintenance and depressive episodes of bipolar disorder?
Lithium
Valproic acid is also good, although not shown to be as efficacious in treating the depressive symptoms
How can lamotrogene be used for treating bipolar disorder?
It can be used to treat the depressive phase
