What is lithium used in for mainly .. ?
Main therapy for bipolar disorder
18 years old who you suspect to have lithium toxicity. Level was 1.6 mEQ/liter … How do you interpret the level ?
It have a narrow therapeutic index (0.6-1.2 mEq/L)
What does it mean to have a narrow therapeutic index ?
In chronic use It can have a high saturation burden on the body. So even a low level does not means that brain is not highly saturated.
How much does it take lithium to completely absorbed and reach peak effect ?
Peak levels are reached within 2 - 4 hours.
When do you think absorption of lithium will be slowed down .. ?
- In massive overdose - sustained release preparations - chronic therapy - elderly
How long do you think it will take for distribution to the brain ?
Can take up to 24 hours
How do you think lithium is eliminated from the body ?
95 % by the kidney
How do you think lithium is similar to sodium ?
Any condition that causes sodium to be reabsorbed will increase the reabsorption of lithium from the proximal tubules as well.
What are the conditions that will increase the lithium reabsorption and causes toxicity ?
- advanced age - decreased GFR - decreased sodium intake - thiazide diuretics - NSAID
17 years old who took a high dose of lithium of his brother medications. What is the main clinical signs you expect to see ?
- Delayed toxicity due to delayed distribution - High serum levels initially do not correlate with toxicity - GI symptoms is the most common initial presentation. - neurological toxicity might be seen delayed.
50 years old who is maintained on lithium who presented with AMS and ataxia .. His level was 1.9 mEQ/liter How can you interpret this level in his case .. ?
- Decreased excretion - Serum levels lower since intracellular levels high - Subacute/nonspecific neurologic symptoms - GI symptoms less severe - Encephalopathy, myoclonus, ataxia severe rigidity, seizures can be seen
What EKG findings can be seen .. ?
- Bradycardia - T-wave flattening/inversion - QT prolongation
18 years old M. Presnted with overdose and you suspect lithium to be involved .. What diagnostic tests would you do .. ?
- serum lithium level. - Electrolytes - renal function - EKG
Main points to consider when interpreting lithium levels?
- serum levels does not correlate with symptoms - serum levels does not correlate with brain levels of saturation - you need to send level in a lithium free tube.
In the above patient . Levels turned to be 2 mEQ/liter .. What initial management approach you will take .. ?
- stop any lithium or offending drugs. - improve the GFR and kidney perfusion . Will give you 20 % reduction in lithium level in 6 hours - hydrate patient IVF as tolerated. - avoid forced diuresis. - consider hemodialysis
When to consider hemodialysis .. ?
- severe neurotoxicity - can not tolerate volume overload - acute lithium concentration 4 mEQ/liter - chronic level > 2.5 mEQ/liter
What do we mean by the rebound phenomenon in lithium .. ?
where clearance of plasma compartment is followed by redistribution from tissue compartment
When to consider Activated charcoal for GI decon .. ?
- activated charcoal does not bind lithium. - is quickly absorbed so role is limited - sometimes Whole bowel irrigation might be considered in large sustained release overdose.
What do we mean by SILENT syndrome ?
- syndrome of irreversible lithium-effectuated neurotoxicity - it is a neurologic dysfunction caused by lithium in the absence of prior neurologic illness, which persists for a period of at least 2 months following cessation of the drug. ( rare ) ..
What do you think the most bad prognostic sign in chronic lithium toxicity .. ?
Hyperthermia
