Mood stabilizers (mania) Flashcards
What is the use for mood stabilizers?
Mood stabilizers are medications used to prevent the extreme mood swings between mania and depression typically seen in bipolar disorder
Why is therapeutic drug monitoring required for lithium?
The therapeutic range is very narrow and thus requires monitoring
Why is volume of distribution important in lithium administration?
The volume of distribution for lithium is approximately equal to body water therefore anything that changes body water can cause a toxic increase in circulating lithium levels
- Thiazide diuretic use
- Intense exercise
- Diarrhea.
What signs of toxicity are associated with lithium?
Signs and symptoms of toxicity include:
- nausea
- vomiting
- diarrhea
- ataxia
- depressed thyroid function
- cognitive slowing
What side effects are associated with lithium?
- Lethargy
- Weight gain
- Blurred vision
- Slight tremble in the hands
- Feeling of being mildly ill
- Reversible nephrogenic diabetes insipidus also sometimes seen.
To what pharmacologic drug class does lithium belong?
Anti-mania, mood stabilizer, headache prophylaxis esp. cluster headaches
What is the (proposed) mechanism of action of lithium?
- Alter Na+ transport in nerve and muscle cells
- Inhibit the recycling of neuronal membrane phosphoinositides involved in generation of second messengers
- Inhibition of glycogen synthase kinase 3, inositol phosphatases
- Modulating glutamate receptors.
What are the major drug interactions with lithium?
diuretics, NSAID , ACE inhibitors, calcium channel blockers
What special considerations should be taken with lithium?
- pregnancy risk factor D,
- CAUTION for hypersensitivity to drug/class
- Brugada syndrome
- elderly pts
- renal impairment, volume depletion
- cardiovascular disease
- thyroid disorder
- concurrent CNS depressant use, alcohol use
What is the route of administration for lithium?
by mouth (po)
Which anti-epileptic drugs are also effective for mania?
Valproic acid, Carbamazepine, Oxcarbazepine and Lamotrigine
- See anti-epilepsy deck
What special considerations should be taken with Valproic acid (valproate–see epilepsy deck for full pharm info)?
- Pregnancy risk factor D
- Reduces clearance of carbamazepine and lamotrigine
What should be monitored in patients on Valproate?
- Obtain baseline complete blood cell counts with differential (CBC with diff every 3-6 months)
- Liver function tests (every 3-6 months)
- Pregnancy test for females.
- Monitor for development of polycystic ovary disease in females
What are the black box warnings associated with Valproate?
Hepatotoxicity, Teratogenic, Pancreatitis
What are the black box warnings associated with lamotrigine?
SERIOUS SKIN RASHES:
- Requires hospitalization
- Stevens-Johnson syndrome
- Rare cases of toxic epidermal necrolysis, and rash-related deaths
What is oxcarbazepine?
Oxcarbazepine is a structural derivative of carbamazepine.
- It has a reduced effect on inducing liver metabolizing enzymes which means less dose modification.
- More expensive than carbamazapine currently.
- See carbamazepine cards
Describe the pharmacodynamics of oxcarbazepine.
- Blocks voltage-sensitive Na channels (like Carbamazepine with fewer side effects)
- Stabilizes neural membranes
- Inhibits repetitive firing, and decrease synaptic impulse propagation
To what drug class does olanzapine belong?
Atypical anti-psychotic, mood stabilizer
Describe the pharmacodynamics of olanzapine.
Blocks 5HT2A and D2 receptors similar to clozapine
Describe the pharmacokinetics of olanzapine.
- Metabolized extensively by the liver
- CYP450: 1A2, 2D6 (minor), 2C19 substrate
- Urine 57% (7% unchanged), feces 30%
- Half-life: 21-54h
What toxicity is associated with olanzapine?
- Drowsiness
- Flu syndrome
- Weight gain
- Salivation
- Tardive dyskinesia,
- QTc prolongation (all anti-psychotics)
- Rarely neuroleptic malignant syndrome.
What special considerations should be taken with patients on olanzapine?
- Pregnancy risk factor C (preferred bipolar med. for pregnancy)
- p450 inducers
What is the route of administration for olanzapine?
- p.o.
- IM
What should be monitored in patients on olanzapine?
- Fasting glucose and lipid panel at baseline, then periodically
- AST/ALT if significant hepatic dz
- CBC frequently during initial TX if pre-existing leukopenia or if drug-induced leukopenia/neutropenia hx
- Weight
- Orthostatic hypotension (IM use)
Why is olanzapine not approved for dementia related psychosis in elderly patients?
- Increased mortality risk in elderly dementia pts. on conventional or atypical antipsychotics
- Most deaths due to cardiovascular or infectious events
What is the clinical management of a patient during a manic episode?
Trials have proved that a combination of an atypical antipsychotic with lithium provides better prophylaxis than does lithium monotherapy, however the weight gain and sedation is prohibitory for many.
