Drugs for Bipolar Disorders Flashcards
Describe the mechanism of action of Lithium
The mechanism is unclear, but may dampen the IP3 second messenger system or inhibit glycogen synthase kinase-3
Name the drugs used to treat bipolar disorders in order by preference.
Lithium, Olanzapine, Valproate, Lamotrigine
What is the indication for Olanzapine?
Bipolar I, especially during manic emergencies because of its sedative effects
What are the common side effects of Lithium?
Low therapeutic index (toxicity can occur with normal therapy), sedation, tremor, edema, acne
What are the clinical indications for Lithium?
Maintenance medication for bipolar disorder, adjunctive therapy in the tx of depression, and an adjunctive tx for schizoaffective disorder
Is Lithium useful during manic episodes?
It can be given but is not the first choice. Olanzapine is good for manic emergencies
Discuss the pharmacokinetic features of Lithium.
It has a gradual response (days to weeks) so it is often given with faster-acting mood stabilizers at first. Given PO and should monitor blood levels. Kidney excretion
Describe the role of renal function while taking Lithium.
Because Lithium has a low therapeutic index, patients with impaired renal clearance are more likely to develop toxicity with normal therapy.
What is the drug of choice for maintenance therapy of bipolar disorder?
Lithium
Describe the clinical use of Valproate.
It is an anticonvulsant often used as an adjunct with lithium for maintenance therapy and is becoming first-line for bipolar II disorder.
Describe the side effects associated with Valproate
GI distress, sedation, weight gain, occasionally hepatotoxicity (monitor LFTs)
Describe the clinical uses of Lamotrigine.
It is an anticonvulsant with significant anti-depressant activity. It is superior to lithium in preventing depressive episodes (though lithium is better for manic episodes) so a combination is recommended.
Describe the side effects associate with Lamotrigine.
Dizziness, nausea, headache, mild rash, rarely but may cause Stevens-Johnson syndrome
What is key in managing acute manic emergencies?
Sedation. Utilize antipsychotics, benzodiazepines, or anticonvulsants (e.g. valproate, lithium)
Is it safe to treat bipolar disorder with antidepressants?
No, this can lead to significant problems by causing a switch from depression to mania (particularly with TCAs and SNRIs) and may also increase the rapidity and depth of cycling.
