Difference between revisions of "Lithium toxicity"

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==Background==
 
==Background==
 
*Mechanism of action is poorly understood.
 
*Mechanism of action is poorly understood.
*Despite availability of newer drugs, Lithium remains most effective tx for bipolar disorder, and it still in use
+
*Despite availability of newer drugs, [[Lithium]] remains most effective treatment for bipolar disorder, and it is still in use
 
*Lithium initially distributes in extracellular fluid, then gradually redistributes to other areas including the brain (takes up to 24 hours after absorption)
 
*Lithium initially distributes in extracellular fluid, then gradually redistributes to other areas including the brain (takes up to 24 hours after absorption)
 
*95% renal excretion
 
*95% renal excretion
**NSAIDs, Diuretics, ACE-inhibitors → ↑ Lithium serum concentration by ↓ lithium excretion
+
**[[NSAIDs]], [[diuretics]], [[ACE-inhibitors]] → ↑ Lithium serum concentration by ↓ lithium excretion
*Lithium toxicity rarely fatal (only 3 deaths in 2009)<ref>Bronstein AC, et al: 2009 Annual Report of the American Association of Poison Control Centers’ National Poison Data System (NPDS). Clin Toxicol (Phila) 2010; 48:979.</ref>
+
*Lithium toxicity rarely fatal (only 11 deaths out of 6815 reported toxic exposures in 2012)<ref> Mowry JB, Spyker DA, Cantilena LR Jr., Bailey JE, Ford M: 2012 annual report of the American association of poison control centers’ national poison data system (NPDS): 30th annual report. Clin Toxicol (Phila) 51: 949–1229, 2013</ref>
  
==Precipitants==
+
===Common Precipitants===
*Overdose
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*[[Overdose]]
*Renal failure
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*[[Renal failure]]
 
*Volume depletion
 
*Volume depletion
**Diuretic use, vomiting, diarrhea, diaphoresis, decreased oral intake
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**[[Diuretic]] use, [[vomiting]], [[diarrhea]], diaphoresis, decreased oral intake
*Hyperthermia
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*[[Hyperthermia]]
 
*Infection
 
*Infection
*CHF
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*[[CHF]]
 
*Surgery
 
*Surgery
*Cirrhosis
+
*[[Cirrhosis]]
  
 
==Clinical Features==
 
==Clinical Features==
Three recognized patterns of Lithium toxicity - "Acute", "Acute-on-chronic", and "Chronic".<ref>Waring WS, Laing WJ, Good AM, Bateman DN. Pattern of lithium exposure predicts poisoning severity: evaluation of referrals to a regional poisons unit. QJM. 2007 May;100(5):271-6. Epub 2007 Apr 5.</ref>
+
''Three recognized patterns of Lithium toxicity - "Acute", "Acute-on-chronic", and "Chronic".<ref>Waring WS, Laing WJ, Good AM, Bateman DN. Pattern of lithium exposure predicts poisoning severity: evaluation of referrals to a regional poisons unit. QJM. 2007 May;100(5):271-6. Epub 2007 Apr 5.</ref>''
  
 
===Acute===
 
===Acute===
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Serum concentrations can fall rapidly as lithium redistributes to tissues, and serum level does not correlate with degree of toxicity. GI symptoms predominate.
 
Serum concentrations can fall rapidly as lithium redistributes to tissues, and serum level does not correlate with degree of toxicity. GI symptoms predominate.
  
*GI - nausea, vomiting, diarrhea, abdominal pain
+
*GI - [[nausea/vomiting]], [[diarrhea]], [[abdominal pain]]
 
**Earliest and most common symptoms
 
**Earliest and most common symptoms
*Cardiac effects - bradycardia, QT prolongation, T-wave flattening or inversion<ref>Canan F, Kaya A, Bulur S, Albayrak ES, Ordu S, Ataoglu A. Lithium intoxication related multiple temporary ecg changes: A case report. Cases Journal. 2008;1:156. doi:10.1186/1757-1626-1-156.</ref>
+
*Cardiac effects - [[bradycardia]], [[QT prolongation]], T-wave flattening or inversion<ref>Canan F, Kaya A, Bulur S, Albayrak ES, Ordu S, Ataoglu A. Lithium intoxication related multiple temporary ecg changes: A case report. Cases Journal. 2008;1:156. doi:10.1186/1757-1626-1-156.</ref>
**Can also cause Brugada-like ECG pattern
+
**Can also cause [[Brugada]]-like ECG pattern
 
*CNS Depression - late finding (takes time for lithium to distribute to CNS), indicates progression of toxicity
 
*CNS Depression - late finding (takes time for lithium to distribute to CNS), indicates progression of toxicity
  
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===Chronic===
 
===Chronic===
Occurs insidiously in patients on chronic lithium therapy. Toxicity is 2/2 increased absorption or decreased elimination. CNS symptoms predominate.
+
Occurs insidiously in patients on chronic lithium therapy. Toxicity is secondary to increased absorption or decreased elimination. CNS symptoms predominate.
  
 
Chronic lithium therapy is associated with nephrogenic diabetes insipidus, which → hyponatremia, fluid loss → ↑ lithium levels (can precipitate toxicity)
 
Chronic lithium therapy is associated with nephrogenic diabetes insipidus, which → hyponatremia, fluid loss → ↑ lithium levels (can precipitate toxicity)
  
 
*Neurotoxicity is major finding, and is generally more profound than that seen in acute toxicity
 
*Neurotoxicity is major finding, and is generally more profound than that seen in acute toxicity
**Mild symptoms include tremor, drowsiness
+
**Mild symptoms include [[tremor]], drowsiness
**Progressive symptoms include hyperreflexia, confusion, ataxia, seizures, extrapyramidal signs, coma
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**Progressive symptoms include hyperreflexia, [[confusion]], [[ataxia]], [[seizures]], [[extrapyramidal symptoms]], [[coma]]
*Hypothyroidism (lithium inhibits thyroid hormone release)
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*[[Hypothyroidism]] (lithium inhibits thyroid hormone release)
  
====Syndrome of Irreversible Lithium-Effectuated Neurotoxicity (SILENT)<ref>Adityanjee, Munshi KR, Thampy A. The syndrome of irreversible lithium-effectuated neurotoxicity. Clin Neuropharmacol. 2005 Jan-Feb;28(1):38-49.</ref>====
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===Syndrome of Irreversible Lithium-Effectuated Neurotoxicity (SILENT)<ref>Adityanjee, Munshi KR, Thampy A. The syndrome of irreversible lithium-effectuated neurotoxicity. Clin Neuropharmacol. 2005 Jan-Feb;28(1):38-49.</ref>===
Persistent sequelae of lithium toxicity. Defined as neurologic dysfunction persisting more than 2 months after cessation of lithium therapy. Exact mechanism unknown (possibly related to CNS demyelination).
+
*Persistent sequelae of lithium toxicity
 +
*Defined as neurologic dysfunction persisting > 2 months after cessation of lithium therapy
 +
*Exact mechanism unknown (possibly related to CNS demyelination).
 +
*Symptoms
 +
**Cerebellar dysfunction ([[dysarthria]], [[ataxia]], [[tremor]], gait instability)
 +
**Peripheral neuropathy
 +
**[[Extrapyramidal symptoms]]
 +
*Brainstem dysfunction
 +
*[[Dementia]]
  
Symptoms
+
==Differential Diagnosis==
*Cerebellar dysfunction
+
{{Heavy metals list}}
*Peripheral neuropathy
 
*Extrapyramidal symptoms
 
*Brainstem dysfunction
 
*Dementia
 
  
==Diagnosis==
+
==Evaluation==
 
*Lithium level
 
*Lithium level
 
**Therapeutic level = 0.6-1.2 meq/L
 
**Therapeutic level = 0.6-1.2 meq/L
**''level may be falsely elevated if placed in a green top tube due to the heparin lithium interaction''
+
**''Serum level may be falsely elevated if placed in a green top tube due to the heparin lithium interaction''
 +
**''Serum levels do not predict CNS levels and only roughly correlate with clinical symptoms''
 
*Metabolic Panel
 
*Metabolic Panel
 
*TSH
 
*TSH
*ECG
+
*[[ECG]]
 
*Acetaminophen and Salicylate Levels (possible coingestants)
 
*Acetaminophen and Salicylate Levels (possible coingestants)
  
==Treatment==
+
==Management==
*GI decontamination
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===GI decontamination===
**Consider lavage for massive ingestions (>4gm) if can be performed w/in 1hr
+
*[[Whole bowel irrigation]] (only for extended release tablets)
**Activated charcoal is ineffective
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*[[Gastric lavage]] and [[activated charcoal]] not effective and potentially harmful
*Fluid resuscitation
+
===[[Fluid resuscitation]]===
**Average pt has Na/volume deficit; giving fluid helps reestablish normal Li excretion
+
*Average patient has Na/volume deficit; giving fluid helps reestablish normal renal Lithium excretion
***Give 2L NS bolus; then give 200mL/hr
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*Give 2L NS bolus, then start 200mL/hr or 2x maintenance rate
*Seizure
+
===[[Hemodialysis]]===
**Benzos are 1st line
+
''Most effective method of removal. Must follow serial lithium levels - levels will likely rise after HD due to redistribution from tissues; additional HD may be required.''
**Phenobarbital is 2nd line
+
'''Indications:'''
**Phenytoin is ineffective
+
*Kidney function is impaired and the [Li+] >4.0 mEq/L (1D recommendation)<ref name="extra">Extracorporeal Treatment for Lithium Poisoning: Systematic Review and Recommendations from the EXTRIP Workgroup. Decker BS et al. Clin J Am Soc Nephrol 2015 Jan 12 [http://www.extrip-workgroup.org/#!recommendations/cy1f Extrip Recs]</ref>
*Dialysis
+
*Clinical deterioration
**Indications:
+
*In the presence of a decreased level of consciousness, seizures, or life-threatening dysrhythmias irrespective of [Li+] (1D)<ref name="extra"></ref>
***Li level >4 (acute overdose)
+
*[Li+].>5.0 mEq/L (2D suggestion)
***Li level >3.5 (chronic toxicity)
+
*If the expected time to obtain a [Li+]<1.0 mEq/L with optimal management is >36 h (2D suggestion)<ref name="extra"></ref>
***Little change in Li level after 6hr IVF
+
*Baseline renal failure
***Sustained Li level >1.0 after 36hr
+
*Contraindication to aggressive fluid resuscitation (CHF, etc)
***Baseline renal failure
+
*Make final decision after consulting toxicologist and/or nephrologist since it's a complex decision <ref>Internet Book of Critical Care (IBCC) Lithium intoxication https://emcrit.org/ibcc/lithium/#dialysis</ref>
***Ingestion of sustained-release preparations
 
**Goal:
 
***Li level <1
 
****Must monitor for up to 8hr following dialysis to ensure levels stay <1
 
  
 
==Disposition==
 
==Disposition==
*Consider discharge for pts who are asymptomatic after 4-6hr obs, 2 downtrending lithium levels, and no worsening of renal function
+
*Consider discharge for patients who are asymptomatic after 4-6hr obs, 2 downtrending lithium levels, and no worsening of renal function
*Admit all pts w/ Li level >1.5
+
*Admit all patients with Li level >1.5
*Admit all pts w/ ingestion of sustained-release preparation (regardless of Li level)
+
*Admit all patients with ingestion of sustained-release preparation (regardless of Li level)
  
 
==See Also==
 
==See Also==
 
*[[Toxicology (Main)]]
 
*[[Toxicology (Main)]]
 +
*[[Lithium]]
 +
*[[Heavy metals]]
  
 
==References==
 
==References==
 
<references/>
 
<references/>
*Tintinalli
 
*Rosen's Chapter 160 - Lithium
 
  
[[Category:Tox]]
+
[[Category:Toxicology]]

Latest revision as of 06:43, 9 March 2021

Background

  • Mechanism of action is poorly understood.
  • Despite availability of newer drugs, Lithium remains most effective treatment for bipolar disorder, and it is still in use
  • Lithium initially distributes in extracellular fluid, then gradually redistributes to other areas including the brain (takes up to 24 hours after absorption)
  • 95% renal excretion
  • Lithium toxicity rarely fatal (only 11 deaths out of 6815 reported toxic exposures in 2012)[1]

Common Precipitants

Clinical Features

Three recognized patterns of Lithium toxicity - "Acute", "Acute-on-chronic", and "Chronic".[2]

Acute

Occurs in patients not previously receiving lithium (i.e. with no current body stores)

Serum concentrations can fall rapidly as lithium redistributes to tissues, and serum level does not correlate with degree of toxicity. GI symptoms predominate.

Acute-on-Chronic

Also called "Acute-on-therapeutic", occurs in patients currently taking lithium due to acute ingestion of supra-therapeutic doses.

  • Symptoms are a mix of both acute and chronic - includes both GI and CNS effects

Chronic

Occurs insidiously in patients on chronic lithium therapy. Toxicity is secondary to increased absorption or decreased elimination. CNS symptoms predominate.

Chronic lithium therapy is associated with nephrogenic diabetes insipidus, which → hyponatremia, fluid loss → ↑ lithium levels (can precipitate toxicity)

Syndrome of Irreversible Lithium-Effectuated Neurotoxicity (SILENT)[4]

  • Persistent sequelae of lithium toxicity
  • Defined as neurologic dysfunction persisting > 2 months after cessation of lithium therapy
  • Exact mechanism unknown (possibly related to CNS demyelination).
  • Symptoms
  • Brainstem dysfunction
  • Dementia

Differential Diagnosis

Heavy metal toxicity

Evaluation

  • Lithium level
    • Therapeutic level = 0.6-1.2 meq/L
    • Serum level may be falsely elevated if placed in a green top tube due to the heparin lithium interaction
    • Serum levels do not predict CNS levels and only roughly correlate with clinical symptoms
  • Metabolic Panel
  • TSH
  • ECG
  • Acetaminophen and Salicylate Levels (possible coingestants)

Management

GI decontamination

Fluid resuscitation

  • Average patient has Na/volume deficit; giving fluid helps reestablish normal renal Lithium excretion
  • Give 2L NS bolus, then start 200mL/hr or 2x maintenance rate

Hemodialysis

Most effective method of removal. Must follow serial lithium levels - levels will likely rise after HD due to redistribution from tissues; additional HD may be required. Indications:

  • Kidney function is impaired and the [Li+] >4.0 mEq/L (1D recommendation)[5]
  • Clinical deterioration
  • In the presence of a decreased level of consciousness, seizures, or life-threatening dysrhythmias irrespective of [Li+] (1D)[5]
  • [Li+].>5.0 mEq/L (2D suggestion)
  • If the expected time to obtain a [Li+]<1.0 mEq/L with optimal management is >36 h (2D suggestion)[5]
  • Baseline renal failure
  • Contraindication to aggressive fluid resuscitation (CHF, etc)
  • Make final decision after consulting toxicologist and/or nephrologist since it's a complex decision [6]

Disposition

  • Consider discharge for patients who are asymptomatic after 4-6hr obs, 2 downtrending lithium levels, and no worsening of renal function
  • Admit all patients with Li level >1.5
  • Admit all patients with ingestion of sustained-release preparation (regardless of Li level)

See Also

References

  1. Mowry JB, Spyker DA, Cantilena LR Jr., Bailey JE, Ford M: 2012 annual report of the American association of poison control centers’ national poison data system (NPDS): 30th annual report. Clin Toxicol (Phila) 51: 949–1229, 2013
  2. Waring WS, Laing WJ, Good AM, Bateman DN. Pattern of lithium exposure predicts poisoning severity: evaluation of referrals to a regional poisons unit. QJM. 2007 May;100(5):271-6. Epub 2007 Apr 5.
  3. Canan F, Kaya A, Bulur S, Albayrak ES, Ordu S, Ataoglu A. Lithium intoxication related multiple temporary ecg changes: A case report. Cases Journal. 2008;1:156. doi:10.1186/1757-1626-1-156.
  4. Adityanjee, Munshi KR, Thampy A. The syndrome of irreversible lithium-effectuated neurotoxicity. Clin Neuropharmacol. 2005 Jan-Feb;28(1):38-49.
  5. 5.0 5.1 5.2 Extracorporeal Treatment for Lithium Poisoning: Systematic Review and Recommendations from the EXTRIP Workgroup. Decker BS et al. Clin J Am Soc Nephrol 2015 Jan 12 Extrip Recs
  6. Internet Book of Critical Care (IBCC) Lithium intoxication https://emcrit.org/ibcc/lithium/#dialysis