Lithium and valproate Flashcards Preview

Toxicology > Lithium and valproate > Flashcards

Flashcards in Lithium and valproate Deck (13):
1

How is lithium eliminated

95% renal from the proximal tuble

2

List factors that can reduce the excretion of lithium

advanced age
volume depletion
decreased Na in diet
low flow CHF
diabetes insipidus
Meds: thiazide diuretics, NSAIDs ACE-I/ARBs

3

What are side effects of Li at therapeutic doses

tremor, NVD, nephrogenic DI, hypoth, leukocytosis, conduction abN (rare)
Teratogenic

4

How does acute Li toxicity present?

GI: N/V/D
CNS: H/A, tremulousness, dystonia, hyperreflx, ataxia, agitation, lethargy, coma, sz,
CVS: ventricular dysrhythmias, sinus arrest, asystole

5

What permanent neurologic sequele can result from chronic Li toxicity

(SILENT [syndrome of irreversible lithium effectuated neuro toxicity]syndrome)
- Cognitive impairment
- Sensorimotor peripheral neuropathy
Cerebellar dysfunction

6

How does chronic Li toxicity present

less GI
Renal: nephrogenic DI, interstitial nephritis, renal failure
Mostly neuro: Parkinson syndrome, psychosis
CVS: myocarditis
Hypothyroid
aplastic anemia

7

What 2 syndromes is Li toxicity also assoc with

NMS
serotonin syndrome

8

How can Li be decontaminated?

WBI
does not bind to AC

9

What is the mainstay of Tx for Li toxicity

IV fluids and dialysis

10

What are the indications for dialysis in Li toxicity

acute level GT 4 mEq/L
Chronic level GT 2.5mEq/L

Clinical: neurotoxicity
renal failure
unable to tolerate volume
shoch
worsening despite max therapy

11

What is required for valproic acid metabolism

Carnitine and acetyl-Co-A. Depletion of carnitine halts metabolism through oxidation and can cause hyperammonemia

12

What are the clinical manifestations of VPA overdose?

CNS: lethargy to encephalopathy
CVS: hypocalcemia: can cause prolonged QT
HyperNa
pancytopenia
pancreatitis, hepatitis via aberrant FFA metabolism (not hypersensitivity)
ARF

13

What are the therapies for VPA overdose?

AC, HD
Carnitine if liver failure, coma, hyperammonemia (GT 100umol/L or 2xULN