What You Need to Know to Safely Take Lithium

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Lithium is a mood stabilizer used to prevent and treat manic episodes in people with bipolar disorder. If you've been prescribed this drug, it's important to know how to use it safely. This involves being aware of its potential side effects, as well as recognizing why it is critical to follow through with regular testing at lithium monitoring labs.

Most Important Information to Know About Lithium

  • Serious side effects can occur when taking lithium, and taking even a little too much can be dangerous to your health.
  • Regularly monitoring your lithium level is extremely important for taking this drug safely.

Possible Side Effects of Lithium

As with most any medication, lithium can come with a number of side effects. Some lithium side effects are common and mild. Others don't happen as often but can be serious, requiring medical attention.

Common Side Effects

The most common side effects of lithium tend to be more annoying than dangerous. They include:

  • Acne-like rash
  • Appetite changes
  • Diarrhea
  • Dizziness
  • Dry mouth
  • Frequent urination
  • Hair loss or thinning
  • Hand tremors
  • Headache
  • Increased thirst
  • Nausea or vomiting
  • Swelling (edema)

Another common side effect of lithium is weight gain. This effect tends to occur in the first two years of taking the drug and is associated with many factors, such as being on other medications that also cause weight gain, increased thirst leading to high-calorie drink consumption, and hypothyroidism or edema.

A 2016 study found that the medication Metformin may help reduce or prevent weight gain for some people on lithium therapy.

If any of these common effects are bothersome or don't go away, talk with your healthcare provider. They may modify your dosage or change medications to help ease these effects.

Serious Side Effects

Other lithium side effects are more serious, often requiring immediate medical attention. Serious lithium side effects include:

  • Blacking out or fainting
  • Blurry vision
  • Chest tightness or shortness of breath
  • Confusion or hallucinations
  • Movements that are slow or jerky
  • Ringing in the ears or pounding noises inside your head
  • Seizures
  • Speech issues
  • Uncontrollable shaking

If any of these side effects are experienced when taking lithium, contact your healthcare provider immediately or seek emergency medical attention.

Lithium Toxicity

If lithium levels get too high, it can result in toxicity. Lithium toxicity, also sometimes referred to as lithium poisoning, can appear in one of three forms:

  • Acute lithium toxicity: This type of toxicity results from taking too much lithium on one occasion.
  • Chronic lithium toxicity: This type is generally unintentional, resulting from taking in more lithium than the body can eliminate over time.
  • Acute-on-chronic lithium toxicity: Toxicity can also occur if you typically take your lithium as prescribed, but take too much on a particular day.

Mild cases of lithium toxicity can result in symptoms such as weakness, tremors, poor concentration, and diarrhea. In severe cases, it can lead to vomiting, more noticeable tremors, slurred speech, lethargy, and confusion.

While lithium toxicity is generally not fatal, it does require treatment. It may also require an extended hospital stay due to mobility and cognitive complications.

If you suspect lithium toxicity, call the Poison Help hotline at 800-222-1222 or seek immediate medical attention.

Drug Interactions With Lithium

There are several drugs that can interact with lithium, resulting in increased lithium levels in the blood. These include:

  • Angiotensin II receptor antagonists (ARBs) such as Diovan (valsartan) and Cozaar (losartan)
  • Angiotensin-converting enzyme inhibitors (ACE inhibitors) like Vasotec (enalapril) and Prinivil (lisinopril)
  • Diuretics, also referred to as water pills
  • Non-steroidal anti-inflammatory drugs (NSAIDs) such as Advil (ibuprofen) and Aleve (naproxen)

In contrast, other substances have been found to lower lithium levels, potentially reducing this drug's therapeutic effects. They include caffeine, table salt, and theophylline, a medication sometimes prescribed for breathing issues.

Due to caffeine and table salt being on this list, the prescribing physician may provide special dietary instructions to follow when taking lithium. This could involve avoiding low-sodium diets, drinking enough fluids, and limiting caffeine intake.

This is not a comprehensive list of substances that may interact with lithium. Therefore, it's important to tell your healthcare provider about any drugs, prescription medications, supplements, or herbal remedies you are taking to help verify that they won't impact your treatment.

Monitoring Tests During Lithium Therapy

If lithium levels get too high, it can be problematic for the kidneys, parathyroid, and thyroid glands. This makes regular testing at lithium monitoring labs important for taking this drug safely.

For example, almost half of patients experience some degree of excessive urination after starting lithium, with 15% to 20% of these individuals developing nephrogenic diabetes insipidus (NDI). NDI is a condition in which the kidneys are unable to concentrate the urine resulting in excess urination (polyuria) and excess thirst (polydipsia).

Process of Monitoring Lithium Levels

Before treatment is started, tests are ordered to assess kidney and thyroid function. Lithium is excreted from the body by the kidneys, so if the kidneys are malfunctioning to any degree, levels of lithium can build up in the blood.

Blood lithium levels are then analyzed regularly during treatment. For instance, they are often checked five days after a dosage change, as the drug's levels begin to stabilize. Levels should also be checked if any new medications are added or discontinued since many medications interact with lithium.

Tests used to monitor lithium levels and this drug's effects may include:

  • Calcium levels: Lithium can enter calcium channels and stop this nutrient from passing through. Checking serum calcium levels can help determine if this is occurring.
  • Kidney tests: Regularly testing your eGFR and creatinine levels can help your practitioner keep an eye on your kidney function.
  • Thyroid tests: It's important to note that anyone diagnosed with bipolar disorder should have their thyroid function monitored frequently—even if not on lithium. This is because abnormal thyroid hormone levels appear to play a role in bipolar mania and depression.

Additional tests, such as blood chemistries and an EKG, may also be used to help monitor safe lithium levels.

Therapeutic Lithium Levels

Lithium has a narrow safety window. This means that there is a fine line between the level of the drug needed to have a therapeutic effect and that which causes toxicity.

The therapeutic level of lithium is usually between 0.8 mmol/L and 1.1 mmol/L at the beginning of treatment, with maintenance levels between 0.6 mmol/L and 0.8 mmol/L. Although, target ranges may be slightly lower for elderly patients.

The dosage of lithium prescribed is usually between 600 milligrams (mg) and 1200 mg per day. However, some people require a higher daily dose to obtain relief from bipolar symptoms.

Coping With Lithium Side Effects and Toxicity

There are several ways in which lithium's side effects and toxicity risk can be reduced. They include keeping the dose low enough so that blood levels are on the lower side of the therapeutic window. The timing of the dose may also be helpful.

Monitoring of blood levels is important on a regular basis, as well as if any new symptoms should arise. In some cases, medications can be used to reduce certain side effects.

Summary

Lithium can be an effective drug for people with bipolar disorder. In some cases, it can even be a lifesaver as this drug has been found to decrease the rate of suicide, which is a significant risk among people with this condition.

If you are having suicidal thoughts, contact the National Suicide Prevention Lifeline at 988 for support and assistance from a trained counselor. If you or a loved one are in immediate danger, call 911.

For more mental health resources, see our National Helpline Database.

That said, careful monitoring of lithium levels is critical to reducing the potential for toxicity and its consequences. While some side effects are common, many of these effects are more annoying than dangerous.

Lab tests must be conducted regularly when taking lithium to minimize the risk of kidney and thyroid dysfunction. With monitoring, however, and a careful understanding of the early symptoms of toxicity, you can enjoy the benefits of this medication without significant risks.

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Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Marcia Purse
Marcia Purse is a mental health writer and bipolar disorder advocate who brings strong research skills and personal experiences to her writing.