From the Guidelines
Symptoms of lithium toxicity include tremors, confusion, slurred speech, nausea, vomiting, diarrhea, drowsiness, muscle weakness, and lack of coordination, and can be life-threatening if not promptly addressed. In more severe cases, patients may experience seizures, coma, cardiac arrhythmias, and even death 1. Early signs often include fine hand tremors, increased thirst, frequent urination, and mild cognitive impairment. Lithium toxicity can develop gradually or suddenly, with risk factors including dehydration, decreased kidney function, sodium depletion, and drug interactions with medications like NSAIDs, ACE inhibitors, and diuretics.
Key Considerations
- Regular monitoring of lithium blood levels is essential for patients taking this medication, with therapeutic levels typically ranging from 0.6-1.2 mEq/L 1.
- Toxicity often occurs at levels above 1.5 mEq/L, though some patients may experience symptoms even within the therapeutic range.
- If lithium toxicity is suspected, the medication should be stopped immediately and medical attention sought, as treatment may require intravenous fluids, kidney support, or in severe cases, dialysis to remove excess lithium from the bloodstream 1.
Monitoring and Prevention
- It is recommended that all people taking potentially nephrotoxic agents such as lithium have their GFR, electrolytes, and drug levels regularly monitored 1.
- Maintaining hydration during intercurrent illness and avoiding concomitant NSAIDs can help prevent lithium toxicity 1.
From the FDA Drug Label
Diarrhea, vomiting, drowsiness, muscular weakness and lack of coordination may be early signs of lithium toxicity, and can occur at lithium levels below 2 mEq/l. At higher levels, giddiness, ataxia, blurred vision, tinnitus and a large output of dilute urine may be seen.
- Symptoms of lithium toxicity include:
- Diarrhea
- Vomiting
- Drowsiness
- Muscular weakness
- Lack of coordination
- Giddiness
- Ataxia
- Blurred vision
- Tinnitus
- Large output of dilute urine Lithium toxicity can occur at serum levels below 1.5 mEq/l in sensitive patients, and the risk of toxicity increases with increasing serum lithium levels 2.
From the Research
Symptoms of Lithium Toxicity
- Confusion 3
- Ataxia 3
- Seizures 3, 4
- Altered sensorium 4
- Renal insufficiency 4
- Neurologic symptoms, such as cerebellar dysfunction 3
- Cardiovascular symptoms 5
Factors Influencing Symptoms
- The type of lithium poisoning (acute, acute-on-chronic, or chronic) can influence the severity of symptoms 5, 3, 6
- Patients with chronic lithium poisoning are more likely to have severe symptoms 5, 3
- Underlying diseases and renal impairment can modify lithium toxicity and kinetics 6
- High-risk factors for toxicity, such as dehydration, can increase the chances of lithium toxicity in patients on long-term lithium therapy 4