Lithium Flashcards
What is the main indication for the mood stabilizer Lithium ?
For the Tx of bipolar disorder.
How is lithium used in Bipolar disorder ?
As a maintenance therapy and also as an acute agent, however the preferred acute agent is a atypical antipsychotics
When is lithium used in unipolar disorder ?
When it does not respond to conventional anti-depressents.
What is the MOA of Lithium ?
The exact mechanism is unknown. However, the current understanding is that the lithium inhibits the enzyme IPpase responsible for converting IP2 to IP1 as well as the enzyme IMpase responsible for converting IP1 to inositol by displacing the MG2+ iron from both of these enzymes. The ultimate effect is impaired inactivation of presynaptic T-type Ca2+ channels leading to reduced excitatory and inhibitory neurotransmitter release conferring the mood stabilising effect.
What is the therapeutic window of lithium ?
Narrow and require close serum monitoring to prevent adverse effects especially in people with renal diseases as lithium is exclusively excreted by the kidneys.
What are the medications that reduce GFR and increase lithium toxicity ?
- Thiazides and Loop diuretics.
- NSAIDs and ACE inhibitors.
What are the common side effects of lithium ?
*GIT symptoms and tremor
* Polyuria and polydipsia due to inhibition of ADH action on the kidneys leading to nephrogenic diabetes insipidus.
* Inhibition of TSH causing hypothyroidism
* Leukocytosis
What is the teratogenic effect of lithium ?
Ebstain’s anomaly characterised by pathologic caudal position of tricuspid valves.
What are the signs of lithium toxicity ?
Acute renal failure, ataxia, dysarthria, confusion coma and death.
Osmosis link to Lithium
https://www.osmosis.org/learn/Lithium?from=/pa/foundational-sciences/pharmacology-and-pharmacotherapeutics/psychiatry-behavioral-science/mood-stabilizers
