From the FDA Drug Label
ADVERSE REACTIONS Lithium toxicity: The likelihood of toxicity increases with increasing serum lithium levels. Serum lithium levels greater than 1.5 mEq/l carry a greater risk than lower levels. However, patients sensitive to lithium may exhibit toxic signs at serum levels below 1. 5 mEq/l. 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. Information for the patients: Outpatients and their families should be warned that the patient must discontinue lithium therapy and contact his physician if such clinical signs of lithium toxicity as diarrhea, vomiting, tremor, mild ataxia, drowsiness, or muscular weakness occur
The signs of lithium toxicity include:
- Early signs:
- Diarrhea
- Vomiting
- Drowsiness
- Muscular weakness
- Lack of coordination
- Signs at higher levels:
- Giddiness
- Ataxia
- Blurred vision
- Tinnitus
- Large output of dilute urine 1
From the Research
Signs of Lithium Toxicity
The signs of lithium toxicity can vary, but common symptoms include:
- Confusion 2, 3, 4
- Ataxia 2, 3, 4, 5
- Lethargy 4
- Seizures 3
- Bizarre behavior 4
- Expressive aphasia 5
- Cogwheel rigidity 5
- Fine tremors 5
- Gastrointestinal symptoms 6
Diagnosis and Treatment
Diagnosis of lithium toxicity is largely clinical, although the EEG may be helpful in some cases 2. The red cell:plasma lithium ratio may also be a sensitive indicator of intoxication 2. Treatment typically involves prompt and effective measures, including dialysis in severe cases 2, 3, 4.
Types of Lithium Toxicity
There are different patterns of lithium poisoning, including: