Lithium

Lithium is one of the most effective treatments for bipolar disorder, and it has a narrow margin between the level that works and the level that harms. That is why the blood tests are non-negotiable, and why dehydration matters so much.

Monitoring and brands

Lithium levels are checked regularly — weekly at first, then usually every three months once stable — along with kidney and thyroid function, and calcium.

Blood should be taken about 12 hours after your last dose, so keep to your usual dosing time before a test appointment.

Stay on the same brand. Different lithium products are not equivalent, and switching can change your blood level. If your supply looks different, check with us before taking it.

Carry your lithium purple book — the record book, alert card and information booklet — and show it to any healthcare professional treating you.

Toxicity — what to watch for

Toxicity is usually triggered by something raising the level rather than the dose changing:

• Dehydration — vomiting, diarrhoea, fever, hot weather, heavy exercise
• Low salt intake, or a sudden change in diet
• Anti-inflammatories such as ibuprofen — avoid unless agreed with your prescriber
• ACE inhibitors, sartans and diuretics
• Kidney problems

Drink plenty of fluid, keep your salt intake steady, and contact your team if you become significantly unwell.

Everyday points

Take it at the same time each day, usually in the evening, and swallow modified-release tablets whole.

Common effects: mild tremor, increased thirst and urination, weight gain, nausea and a metallic taste. These are not the same as toxicity, but tell your team if they worsen.

Never stop lithium abruptly — it substantially increases the risk of relapse. Any change should be planned with your specialist.

Lithium in pregnancy needs specialist input; do not stop it on your own if you become pregnant.

Frequently asked questions