If someone asked me to name one of my favorite medications in psychiatry, lithium would be near the top of the list.
That sometimes surprises people.
Lithium has developed a reputation as an “old,” complicated, or even scary medication. Patients hear about blood tests, kidneys, thyroid problems, toxicity, and drug interactions. Clinicians may sometimes reach for newer medications simply because lithium appears more difficult to manage.
But lithium has remained in psychiatry for decades for a reason.
It works.
And when it is prescribed thoughtfully, monitored appropriately, and paired with good patient education, lithium can be an extraordinarily useful medication.
Lithium Is Old—and That Is Actually One of Its Strengths
In medicine, “new” does not automatically mean “better.”
Lithium has an unusually long clinical history, particularly in bipolar I disorder, where it remains an important treatment for acute mania and long-term mood stabilization. Contemporary bipolar-disorder guidelines continue to include lithium among major evidence-based treatment options. (CANMAT/ISBD Guidelines)
We know a great deal about lithium precisely because it has been studied and prescribed for so long.
We know its benefits. We know its risks. We know its interactions. And importantly, we know how to monitor for problems.
That makes lithium different from simply prescribing a medication and hoping for the best.
Lithium gives us measurable information.
We can measure the blood concentration. We can monitor kidney function. We can monitor thyroid function and calcium. We can adjust the dose according to response, tolerability, medical conditions, hydration status, and serum levels.
To me, monitoring is not necessarily a weakness of lithium. Monitoring is part of what makes lithium manageable.
A Fun Piece of History: Lithium and 7 Up
Photo via Pexels
Long before lithium became one of psychiatry’s most important mood stabilizers, you could actually find lithium citrate in 7UP. When 7 Up was introduced in 1929, it was originally sold as “Bib-Label Lithiated Lemon-Lime Soda” and contained lithium citrate. Lithium was removed from the formula in 1948. (History)
Today’s 7 Up contains no lithium, and a soft drink was never a substitute for carefully dosed, monitored treatment. But it is a memorable reminder of how long lithium has been part of the story of mood and the mind.
Why I Like Lithium So Much
Lithium is not simply a sedating medication that suppresses symptoms.
For the right patient, it can provide meaningful mood stabilization and prevention of recurrent mood episodes, particularly mania. (Systematic Review)
Another reason lithium receives so much attention is its relationship with suicide risk.
For years, observational studies and several meta-analyses have suggested a reduction in suicide among patients with mood disorders treated with lithium. More recent randomized-trial analyses, however, have been less definitive because suicide is fortunately rare in clinical trials and therefore difficult to study statistically. A 2025 meta-analysis again found fewer suicide attempts and completed suicides with lithium, but the differences did not reach statistical significance. So I think the most scientifically accurate statement is that lithium has important evidence suggesting an anti-suicidal benefit, but the magnitude and certainty of that effect remain debated. (2025 Meta-analysis)
That distinction matters.
Lithium should never replace a comprehensive suicide-risk assessment, psychotherapy, safety planning, appropriate level of care, or treatment of the underlying psychiatric illness.
But its long-term clinical evidence is one reason it remains such an important medication in psychiatry.
Why Are People So Afraid of Lithium?
Usually because they hear one word: toxicity.
And yes—lithium deserves respect.
Its therapeutic concentration and toxic concentration are closer together than with many psychiatric medications. The FDA prescribing information specifically emphasizes regular serum concentration monitoring. (FDA Label)
But “requires monitoring” is not the same thing as “too dangerous to use.” Many medications throughout medicine require laboratory surveillance.
The key is knowing what changes lithium levels.
One of the biggest concepts I teach patients is that the kidneys control lithium clearance. Anything that substantially changes hydration, sodium balance, or renal function can change lithium concentrations.
Vomiting, diarrhea, heavy sweating, dehydration, major dietary sodium changes, and certain medications can therefore turn a previously stable lithium regimen into a potentially unsafe one. (FDA Label)
That is why education matters so much.
My Strategy: Make Lithium Predictable
When I prescribe lithium, my goal is not simply to write a prescription. My goal is to create a system around the medication.
1. I establish a baseline
Before starting lithium, I want to understand the patient’s medical starting point.
FDA prescribing information recommends evaluation of renal function, electrolytes, and thyroid function before initiation, along with review of concurrent medications and pregnancy considerations when applicable. (FDA Label)
Depending on the patient, I generally think about renal function/eGFR, electrolytes, TSH, calcium, medication interactions, pregnancy status when relevant, and additional testing when medically indicated.
2. I start thoughtfully rather than aggressively
I do not believe every patient needs to be pushed toward the highest possible lithium concentration.
The objective is clinical response with the lowest appropriate exposure for that individual patient.
Age, renal function, severity of illness, whether we are treating acute mania versus maintenance, concomitant medications, previous response, and tolerability all influence the decision.
Lithium treatment should be individualized—not treated as a laboratory number alone.
3. I teach patients how to obtain the lithium level correctly
A lithium level without knowing when it was drawn can be misleading.
For standard monitoring, FDA prescribing information recommends obtaining the serum concentration immediately before the next dose when concentrations are relatively stable—approximately 12 hours after the previous dose. (FDA Label)
That simple piece of education prevents a surprising amount of confusion.
4. I teach hydration and sodium consistency
I tell patients:
“Don’t suddenly become a different person with your water and salt intake just because you started lithium. Be consistent.”
Excessive dehydration can raise lithium concentrations. Significant sodium depletion can also affect lithium clearance.
Patients should be particularly cautious during prolonged vomiting, diarrhea, fever, unusually heavy sweating, or other illnesses that can cause dehydration. (FDA Label)
5. I specifically discuss medications that can raise lithium
This is one of the most important parts of lithium education. I want patients to know that medications they may consider routine can matter.
My lithium safety checklist includes:
- NSAIDs, including medications such as ibuprofen and naproxen
- Diuretics, particularly when they alter sodium balance
- ACE inhibitors/ARBs and other renin-angiotensin system medications
- New medications that may affect kidney function or fluid/electrolyte balance
- Dehydration from illness, vomiting, diarrhea, heavy exercise, or heat
- Major changes in sodium intake
- Checking lithium levels after clinically significant medication or health changes
- Watching for symptoms of toxicity such as worsening tremor, vomiting/diarrhea, marked weakness, confusion, poor coordination, slurred speech, or significant changes in alertness
FDA prescribing information specifically identifies NSAIDs, diuretics, and renin-angiotensin system antagonists as medications that can increase lithium concentrations and require closer monitoring. (FDA Label)
6. I monitor the organs lithium can affect
Long-term lithium treatment deserves ongoing surveillance.
I monitor kidney function, thyroid function, calcium, lithium levels, and clinical symptoms at appropriate intervals based on the patient’s situation.
Lithium can cause hypothyroidism, polyuria related to impaired urinary concentrating ability, hypercalcemia/hyperparathyroidism, and chronic renal effects in some patients. FDA labeling therefore recommends ongoing kidney, thyroid, and calcium monitoring. (FDA Label)
These are real risks.
But the solution is not necessarily to avoid lithium. The solution is to look for problems rather than waiting for problems to announce themselves.
What If the Thyroid Changes?
This is another area where patients sometimes become frightened unnecessarily.
A change in thyroid function does not automatically mean that lithium must be abandoned.
The FDA prescribing information specifically notes that when hypothyroidism occurs during lithium treatment, thyroid supplementation may be used while lithium treatment continues when clinically appropriate. (FDA Label)
Treatment decisions depend on the individual patient, the severity of the thyroid abnormality, lithium response, alternatives, and the overall risk-benefit picture.
This is an excellent example of why psychiatry should not be practiced using simple rules such as “side effect = immediately stop medication.” Good psychopharmacology is more nuanced than that.
The Kidney Question
Kidney concerns deserve particular respect because chronic lithium exposure can affect renal function in some patients.
That does not mean kidney damage is inevitable.
It means we should know the patient’s renal function before treatment, follow it over time, avoid preventable episodes of lithium toxicity, reconsider the regimen when kidney function changes, and collaborate with primary care or nephrology when appropriate. (FDA Label)
Some clinicians also use once-daily lithium dosing when clinically appropriate. There is literature suggesting potential renal advantages, although the evidence is not definitive, so I view dosing frequency as an individualized clinical decision rather than a universal rule. (Dosing Review)
I Don’t Want Patients to Fear Lithium—I Want Them to Understand It
This is probably the most important point.
When patients hear “Lithium can be toxic,” they may hear “Lithium is dangerous.”
I would rather teach: “Lithium is a powerful medication that needs a monitoring system.”
Those are very different messages.
A patient who understands lithium knows:
- Why we check blood work
- When the lithium level should be drawn
- Why dehydration matters
- Why they should mention ibuprofen, blood-pressure medication, or a new diuretic
- Why vomiting and diarrhea matter
- Which symptoms should prompt them to contact their clinician or seek urgent evaluation
That patient is not simply taking lithium. They are participating in lithium treatment.
Don’t Fear the Medication. Respect the Medication.
Lithium is certainly not appropriate for every patient.
There are situations in which another treatment is preferable, and there are medical conditions, pregnancy considerations, medication interactions, tolerability problems, and renal concerns that may significantly change the risk-benefit calculation.
But I also do not believe lithium should be dismissed simply because it requires more work. Some of the best treatments in medicine require careful management.
For me, lithium represents something important about psychopharmacology:
The goal is not to find a medication with zero risk. That medication does not exist.
The goal is to choose a treatment where the potential benefit makes sense for the patient, understand the risks, reduce the risks we can control, monitor the risks we cannot eliminate, and educate the patient well enough that we are managing the medication together.
That is why lithium remains one of my favorite medications in psychiatry.
Not because lithium is harmless. Not because lithium is perfect. But because when the diagnosis is appropriate, the patient is carefully selected, and the medication is thoughtfully monitored, lithium can be an exceptionally valuable tool.
Sometimes the medications we should respect the most are not necessarily the medications we should fear the most.
Lithium deserves respect, education, monitoring—and a place at the psychiatric table.
This article is for educational purposes and does not replace individualized medical evaluation, laboratory monitoring, or treatment recommendations from a qualified healthcare professional.
Erwin Baird, MSN, PMHNP-BC
Next Gen Psyche and Wellness, LLC