Lithium poisoning can develop gradually
Sometimes the people around you notice it before the person who takes the medication does. When the dose has stayed the same, the cause is usually a shortage of fluid and salt (or too much loss of fluid and salt). Poisoning can also occur when someone takes too much lithium. Lithium poisoning can be prevented well through careful use and regular checks of the lithium level.
The chance of lithium poisoning increases in these situations:
- Diarrhoea or vomiting
- Excessive loss of fluid through sweating (for example through intensive sport, a visit to the sauna or hot weather) and not drinking enough
- An extreme diet or a low-salt diet
- Loss of appetite, for example during an acute illness or high fever
- Use of certain medicines such as water tablets (diuretics), certain painkillers (not paracetamol), certain medicines for high blood pressure and certain antibiotics
What are the signs of lithium poisoning?
With lithium poisoning you see an increase of ‘ordinary’ side effects such as:
- Trembling, nausea, vomiting, stomach cramps and diarrhoea
- Loss of concentration, sluggishness, drowsiness and sleepiness
- A heavy feeling in arms and legs, muscle weakness
- Walking or talking as if drunk
- Confusion, muscle twitches and seizures
If one or more of these signs occur, the intake of lithium has to be stopped, at least for the time being, and you have to alert a psychiatrist or your doctor. You can also take extra salt and fluid straight away, for example in the form of one or two cups of stock.
Checks when you use lithium
When you use lithium, the amount of lithium in the blood has to be measured regularly (weekly at the start, later every month and in the long term every 3 to at most 6 months) to see that it is not too high or too low. Values between 0.6 and 0.8 mmol/l are taken as normal. The blood is also checked for kidney and thyroid function, and your weight is monitored.
When in doubt, contact your doctor or prescriber straight away.
Read more about medication for bipolarity.
Prof. dr. Jim van Os, Chair Division Neuroscience, Utrecht University Medical Centre. Jim works at the interface of ‘hard’ brain science, health services research, art and subjective experiences of people with ‘lived experience’ in mental healthcare.
Jim has been appearing on the Thomson-Reuter Web of Science list of ‘most influential scientific minds of our time’ since 2014. In 2014 he published his book ‘Beyond DSM-5‘, and in 2016 the book ‘Good Mental Health Care’. In 2026 he published 'Wat psychisch lijden is'.
Want to read more?
Blogs by Jim van Os can be read here
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