I remember a patient, let’s call him David. He’d been doing so well on lithium for his bipolar disorder, truly a new lease on life. Then one week, he started feeling… off. A bit of a tummy ache, some shakiness in his hands he hadn’t noticed before. He almost brushed it off. Thankfully, he didn’t. Because those subtle signs? They were the first whispers of lithium toxicity. It’s a serious thing, this lithium toxicity, and it happens when there’s too much of this medication in your body. It’s something we always discuss carefully because while lithium can be a fantastic help, its safety window is, well, a bit narrow.
What is Lithium Toxicity, Really?
So, lithium itself is a natural salt. We prescribe it mainly for bipolar disorder because it’s excellent at managing mania. But, as I said, there’s a fine line between a dose that helps and one that harms. It doesn’t take a huge misstep to have too much lithium in your system.
How Does It Happen?
There are a few ways lithium toxicity can sneak up:
- Acute (sudden and severe) toxicity: This is usually when someone takes way too much lithium at once, maybe accidentally, or if they suddenly become very dehydrated.
- Acute-on-chronic toxicity: This happens if you’re taking lithium regularly, but then one day you take an extra dose, or perhaps you get sick and dehydrated.
- Chronic (long-term) toxicity: This is a bit trickier. It’s when lithium builds up in your body slowly over time, even if you’re taking your prescribed dose. Things like dehydration, kidney health, or even other medications can affect how your body handles lithium, leading to this gradual increase.
What are the Levels We Watch For?
We keep an eye on lithium levels with a simple blood test. What’s right for one person might be different for another, but generally, we think of it like this:
- Mild toxicity: Around 1.5 to 2.5 mmol/L (that’s millimoles per liter, just a way we measure it).
- Moderate toxicity: Between 2.5 to 3.5 mmol/L.
- Severe toxicity: Anything higher than 3.5 mmol/L. And this is where things can get quite serious.
Spotting the Signs: Symptoms of Lithium Toxicity
The clues your body gives can really vary, depending on how the toxicity came about and how much extra lithium is on board.
When It Hits Suddenly (Acute & Acute-on-Chronic)
If it’s a sudden overload, the first things you’ll probably notice are tummy troubles. These often show up within an hour or so of taking too much lithium:
- Feeling sick to your stomach (nausea) and actually vomiting.
- Diarrhea.
- Pain in your abdomen.
- A bloated stomach.
If the toxicity is moderate to severe, after these gut symptoms, neurological signs – things affecting your brain and nerves – can appear:
- Changes in how you’re thinking, from mild confusion to full-blown delirium.
- Uncontrollable shaking, or tremors.
- Problems with coordination and balance, what we call ataxia.
- Muscle twitches (myoclonus).
- Slurred speech (dysarthria).
- Your reflexes might become overactive (hyperreflexia).
- Uncontrolled eye movements (nystagmus).
- In severe cases, a very high body temperature (hyperthermia), seizures, or even a coma.
If you’re on lithium and these things start happening, you need medical help right away. No waiting.
When It Creeps Up (Chronic Toxicity)
With chronic lithium toxicity, the picture can be a bit different. Often, the kidneys take a hit. This can lead to a few specific kidney conditions:
- Nephrogenic diabetes insipidus: This isn’t like the sugar diabetes most people know. It’s when your kidneys can’t balance fluids properly. You might notice:
- Dehydration (dry mouth, feeling tired, dizzy).
- Being incredibly thirsty all the time (polydipsia).
- Peeing a lot (polyuria).
- Sodium-losing nephritis: Kidney damage here leads to an imbalance of electrolytes, like sodium. Symptoms can include:
- Muscle cramps or weakness.
- Changes in your mental state.
- Fatigue.
- Intense thirst and peeing a lot.
- Nephrotic syndrome: This is when your kidneys let too much protein leak into your urine (proteinuria). You might see:
- High cholesterol.
- Swelling (edema), especially in your legs and feet.
- Loss of appetite.
- Abdominal pain.
- Foamy-looking pee.
Chronic toxicity can also mess with your endocrine system, the one that manages hormones. This might show up as:
- An underactive thyroid (hypothyroidism).
- An overactive thyroid (hyperthyroidism).
- Overactive parathyroid glands (hyperparathyroidism).
If you’re taking lithium long-term and any of these symptoms crop up, please, talk to your doctor as soon as you can.
A Quick Word on Serotonin Syndrome
Sometimes, lithium can contribute to something called serotonin syndrome, especially if you’re taking other medications that affect serotonin levels (like some antidepressants). This is another serious condition. Watch out for:
- Feeling nervous.
- Nausea, vomiting, diarrhea.
- Pupils that look larger than usual (dilated pupils).
- Tremor.
- Feeling agitated or restless.
- Muscle twitching or stiffness.
- Sweating and shivering.
- Confusion, disorientation, or delirium.
- A very rapid heart rate.
- High blood pressure.
Again, if these pop up, it’s an urgent call to your doctor or the emergency room.
What Puts You at Risk for Lithium Toxicity?
So, how does this happen? Usually, it’s one of three things:
Taking Too Much
This could be an accidental double dose, or sadly, sometimes an intentional overdose. Very rarely, a prescribed dose might be increased too quickly.
Trouble Getting Rid of It
Your kidneys are key players in clearing lithium from your body. If they can’t do their job properly, lithium levels can rise. A big factor here is a lack of sodium (salt) and fluid – dehydration. When you’re low on salt and water, your kidneys try to hold onto lithium. This can happen from:
- Vomiting or diarrhea.
- A fever.
- Kidney failure.
- Taking diuretics (water pills).
- Lots of exercise and sweating.
- Not drinking enough water.
- Being on a very low-sodium diet.
- Conditions like congestive heart failure.
- Pregnancy or during labor and delivery.
- Changes in your thyroid function, like hyperthyroidism.
Who’s More Likely to Experience It?
Some folks are at higher risk for chronic lithium toxicity:
- Being over 50 years old.
- Having a thyroid disease.
- Kidney function that’s already not at its best.
- Having diabetes insipidus. In fact, long-term lithium use can sometimes cause this, creating a bit of a cycle.
If any of these apply to you, it just means we need to be extra vigilant with monitoring.
How We Figure Out If It’s Lithium Toxicity
If we suspect lithium toxicity, getting a clear picture quickly is vital. It’s super helpful for us to know:
- How much lithium was taken.
- When it was taken.
- If any other medications or substances were involved.
- Whether it was an accidental or intentional thing.
Then, we’ll likely run some tests:
- Blood tests to check your lithium levels, of course.
- More blood tests for electrolytes (like sodium and calcium) and thyroid-stimulating hormone (TSH) levels.
- A urinalysis (a urine test).
- Kidney function tests (like blood urea nitrogen and creatinine).
- Sometimes, though it’s rare, brain imaging tests.
We’ll also keep a close eye on:
- Your heart with an EKG (electrocardiogram).
- How much you’re peeing.
- Your oxygen levels, usually with a little clip on your finger called a pulse oximeter.
Getting You Back on Track: Treating Lithium Toxicity
Our main goals are to get the extra lithium out of your body and manage any symptoms you’re having.
For Sudden, Serious Cases
If it’s acute or acute-on-chronic toxicity, and especially if you get to the emergency room quickly, treatment might involve:
- Stomach pumping (gastric lavage).
- Whole-bowel irrigation: This involves drinking a special solution (or having it through a tube) to flush the lithium out of your gut.
- Activated charcoal, especially if other drugs were taken too.
- Kidney dialysis (hemodialysis): This is a way to filter your blood if your kidneys are overwhelmed or the toxicity is severe.
- IV fluids to help with hydration and flushing out the lithium.
- Various medications to treat specific symptoms.
You’ll usually be treated in an emergency room, and if it’s severe, you might need care in an intensive care unit (ICU).
Dealing with Long-Term Effects
Chronic lithium toxicity often means kidney damage. Treatment will depend on the specific kidney issue, and sometimes dialysis is needed here too.
What to Expect: The Outlook
How well someone recovers really depends on the type of toxicity, how severe it was, and how fast they got medical help.
If someone has acute lithium toxicity but doesn’t develop those neurological symptoms, they usually don’t have long-term problems. But if serious neurological symptoms do appear, they can, unfortunately, become permanent. That’s why getting help fast is so, so important. In the worst cases, severe toxicity can lead to coma, brain damage, or even be fatal.
Chronic lithium toxicity can be a bit sneaky because symptoms might come on slowly. This delay in diagnosis can lead to long-term kidney and neurological issues.
Staying Safe with Lithium: Prevention is Key for Lithium Toxicity
Preventing lithium toxicity is all about careful management and awareness. Here’s what you can do:
- Take your medications exactly as prescribed: Only take the amount of lithium your doctor has told you to. I often suggest using a labeled pill box or making notes – it’s easy to forget if you’ve taken a dose.
- Store your lithium safely: Keep it where children or others can’t get to it.
- Stay hydrated: Drink water regularly. Dehydration is a big risk factor. If you get sick with vomiting, diarrhea, or a fever, call your doctor.
- Always tell your doctors you take lithium: If you’re starting any new medication, make sure every provider knows lithium is on your list. Some drugs can interfere with how your body handles it.
- Keep your doctors updated on health changes: Things like pregnancy or new hormone issues can make a difference.
- A serious note: If you’re ever having thoughts of harming yourself or intentionally overdosing on lithium, please, please call the Suicide and Crisis Lifeline at 988. There are people ready to talk 24/7. Or, go straight to the nearest emergency room.
If you’re taking lithium long-term, your doctor will recommend regular blood and urine tests. This is our way of keeping an eye on things and catching potential chronic lithium toxicity early. These usually include:
- Checking blood lithium levels 3 to 5 days after starting or changing a dose.
- Checking blood lithium levels every 3 to 6 months once you’re stable.
- Checking electrolytes, urea, and creatinine levels every 3 to 6 months.
- Checking calcium and TSH levels every 6 to 12 months.
Key Things to Remember About Lithium Toxicity
It’s a lot to take in, I know. But here are the main takeaways:
- Lithium toxicity occurs when lithium levels in your blood are too high.
- It can be acute (sudden) or chronic (gradual buildup).
- Symptoms range from stomach upset and tremors to severe confusion, kidney problems, and potentially life-threatening issues.
- Staying hydrated and watching for drug interactions is crucial.
- Regular blood tests are essential for anyone on long-term lithium therapy.
- If you suspect lithium toxicity, seek medical attention immediately.
You’re not alone in managing this. We’re here to help you use lithium safely and effectively. It’s all about teamwork and open communication.