Lithium Toxicity - Types, Symptoms, and Management

What Is Lithium?

Lithium is a monovalent cation that was first approved by the United States. It got its Food and Drug Administration approval as a medication in the 1970s for treating bipolar and other mental health problems. Lithium is a very powerful, antimanic medication with a narrow spectrum of therapeutic usage and safety.

What Are the Uses of Lithium as a Drug?

Lithium can be used as a medication and helps in many ways -

• Lithium helps in producing brain inositol depletion, resulting in reduced response to alpha-adrenergic stimulation.

• Lithium stimulates serotonin to release from the hippocampus.

• Lithium is a cation, and it works the same as potassium and sodium in the process of transportation and cell membrane potential.

• Lithium helps in reducing the neuronal response to neurotransmitters.

What Is Lithium Toxicity?

Lithium toxicity is described as the excessive accumulation of lithium in the body's cells and tissues. Lithium is mainly used as a mood-stabilizing medication to treat bipolar disorder and major depressive disorder. Lithium toxicity results in tremors, increased reflexes, kidney problems, and other health-related issues.

What Are the Types of Lithium Toxicity?

There are three types of lithium toxicity which include acute, chronic, and acute-on-chronic.

1. Acute Toxicity -

The medical risk is less severe in acute toxicity, as the amount of lithium ingestion is less. In acute toxicity, the affected person may have symptoms like vomiting, diarrhea, dizziness, and other mild neurological problems.

2. Chronic Toxicity -

Chronic lithium toxicity can be caused by ingesting little lithium for a while. In people with chronic toxicity, problems like nystagmus (a condition in which eyes make uncontrolled movements), tremors (involuntary shaking of the body), hyperreflexia (overresponsive bodily reflexes), ataxia (a group of disorders affecting the co-ordination of balance and speech), and changes in the mental state are seen. Other symptoms like vomiting and diarrhea are common.

3. Acute-On-Chronic Toxicity -

The intake of lithium daily can cause acute-on-chronic lithium toxicity, but the amount of lithium may vary.

What Are the Signs and Symptoms Associated With Lithium Toxicity?

The following are the signs and symptoms of the three types of lithium toxicity -

Acute Lithium Toxicity:

• Nausea.

• Vomiting.

• Diarrhea.

• Stomach pain.

• Dizziness.

• Weakness.

• Coma (decreased level of consciousness, lack of responsiveness).

• Hand tremors.

• Lack of coordination of arms and legs.

• Muscle twitches.

• Seizures.

• Slurred speech.

• Uncontrollable eye movement.

• Changes in mental status or altered thinking.

• Slow heart rate.

Chronic Lithium Toxicity:

• Increased reflexes.

• Slurred speech.

• Uncontrolled shaking.

• Kidney failure.

• Drinking a lot of fluid.

• Urinating more or less than normal.

• Memory problems.

• Movement disorders, muscle twitches, hand tremors.

• Problems keeping salts in your body.

• Psychosis (disturbed thought processes, unpredictable behavior).

• Coma (decreased level of consciousness, lack of responsiveness).

• Lack of coordination of arms and legs.

• Seizures.

• Slurred speech.

Acute-On-Chronic Toxicity:

Acute-on-chronic type of toxicity refers to symptoms caused by the intake of lithium for a while, but the quantity of lithium may vary.

There will often be a combination of acute and chronic symptoms, including nervous system and intestinal symptoms.

What Are the Investigations Performed for the Diagnosis of Lithium Toxicity?

Diagnosis of lithium toxicity requires patient evaluation and some investigations -

• Recording the patient’s history to determine the amount of lithium ingested.

• Monitoring urine output.

• Determining the serum electrolytes by a blood test.

• A renal function test is done to check the kidney’s working efficiency.

• Blood glucose level.

• Serum lithium levels.

• Thyroid-stimulating hormone.

• In patients with lithium toxicity, leukocyte count is also increased.

• If the diagnosis is not confirmed, brain imaging can also be done.

What Are the Therapeutic Lithium Levels Indicating Lithium Toxicity?

Lithium is a soft metal that can be administered as a medication for diseases like bipolar disorder. The amount of lithium intake is very important, and it should be precise. A higher dose can cause lithium intoxication.

A therapeutic lithium level is around 0.6 to 1.2 milliequivalent per liter (mEq/L). When the level starts rising from 1.5 milliequivalents per liter or more, the toxicity of lithium starts showing up.

The level of lithium toxicity is classified as -

• Mild- 1.5 to 2.5 mEq/L.

• Moderate - 2.5 to 3.5 mEq/L.

• Severe - above 3.5 mEq/L.

What Is the Management of Lithium Toxicity?

In the early diagnosis of lithium toxicity, the amount of lithium intake should be reduced, and symptomatic treatment should be indicated.

The symptomatic treatment involves

• ACE inhibitors.

• Nonsteroidal anti-inflammatory medications.

• COX-2 inhibitors.

The treatment of lithium toxicity can be managed by three different methods.

1. Decontamination -

• Administration of charcoal to the affected individual. In many studies, it is noted that lithium does not adhere to activated charcoal.

• Gastric lavage has also performed the cases of regular release, and the patient is showing some threatening signs and symptoms. In the cases of massive ingestion, whole bowel irrigation is indicated.

2. Elimination -

• The most effective way to treat lithium toxicity is hemodialysis, particularly in patients with severe signs and symptoms.

• Peritoneal dialysis can also be performed in the case of remote areas as a primary treatment.

3. Disposition -

• All the affected patients should be admitted to the hospital for monitoring and care.

• Patients with moderate to severe symptoms should be shifted to an intensive care unit.

• The lithium serum level should be evaluated every six hours.

• The patient should be monitored until the lithium levels go down to 1.5 milliequivalents per liter (mEq/L), and then the patient can proceed and get discharged.

What Are the Differential Diagnoses for Lithium Toxicity?

Lithium toxicity is a rare disorder and has similar signs and symptoms to other disorders. Therefore it gives a wide range of differential diagnoses.

• Acute hypoglycemia [a condition in which the blood sugar (glucose) level is lower than normal].

• Alcohol toxicity (caused by consumption of excessive alcohol in a short span of time).

• Depression (mood problem related to mental health).

• Heavy metal toxicity (toxicity caused by excessive exposure to heavy metal).

• Mercury toxicity (exposure to mercury causes damage to the brain, lungs, and other internal organs).

• Stroke (blockage in the blood supply to the brain).

• Ischemia (a condition in which blood flow is restricted or reduced in a part of the body).

• Anticholinergic toxicity (it is caused by the excessive intake of anticholinergic drugs).

What Is the Prognosis of Lithium Toxicity?

Lithium toxicity is a curable disease, and it is diagnosed and treated easily, but if it gets ignored, it can result in life-threatening conditions. Lithium toxicity shows a good prognosis and does not leave any damage to the quality of life if it is diagnosed earlier.

Conclusion:

Lithium toxicity is a rare disorder. Lithium is used as medication in many different ways, especially for problems related to mental health. People undergoing some treatment having lithium as a prescribed medicine should be aware of it. It is very important to educate people about lithium toxicity to avoid unfortunate circumstances, and if a person experiences any signs and symptoms should seek medical help.