Medication guide

Lithium (Limas)

What is lithium?

In most countries it's prescribed simply as lithium (brand names include Lithobid in the US and Priadel in the UK); in Japan it's Limas (リーマス on Japanese packaging). It's a long-established mood stabiliser: it calms the highs of mania, and over the longer term it is used to keep mood episodes from coming back. It works within a fairly narrow range, so the dose is guided by simple blood tests.

How is it different from other mood medicines?

Suggested for long-term prevention: Japan's bipolar guideline lists it among the options for preventing both manic and depressive episodes
Evidence on suicide prevention: published research links lithium with a lower risk of suicide
Decades of experience: its effects, risks, and monitoring are well understood
Dosing by blood test: the level is measured directly, so the dose is set for you rather than estimated

What is it used for in Japan?

In Japan, lithium is approved for:

Mania (the elevated, overactive phase of bipolar disorder)

Keeping episodes from coming back is not part of the Japanese approval wording, but Japan's bipolar disorder guideline suggests lithium as one of the options for long-term prevention. Your doctor will explain how it is being used for you.

How does it help?

It settles the highs of mania, and when it is continued over the longer term, it makes both manic and depressive episodes less likely to return. The dose is fine-tuned with blood tests so there's enough to work without too much; that balance is what keeps it both effective and safe.

What should I tell my doctor before starting?

A few situations rule it out entirely; your doctor will choose something else if any of these apply:

Epilepsy or a known brain-wave (EEG) abnormality
A serious heart condition
A state where lithium builds up easily: current kidney problems, being weak and run-down or dehydrated, an illness with fever, sweating or diarrhoea, or a salt-restricted diet

And tell your doctor first if any of these apply; these usually just need adjustments or a closer eye:

Having reacted unusually strongly to lithium before (signs of toxicity even at a normal blood level)
A heart problem in the past, even if it isn't serious now
Kidney problems in the past, or a thyroid condition (overactive or underactive)
Other medicines: especially anti-inflammatory painkillers (e.g. ibuprofen), water tablets (diuretics), and some blood-pressure medicines, which can push your lithium level up
Pregnant, planning to be, or breastfeeding (see the section below; this one matters more than for most medicines)

You'll have regular blood tests for your lithium level (more often at the start, then every few months), and for your thyroid and kidneys. Let your doctor know if you become ill with vomiting, diarrhoea, or fever, as these can raise your lithium level.

How do I take it, and what if I miss a dose?

Lithium is taken every day, in one to three doses as your doctor sets, at a dose guided by your blood level rather than a standard number.

If you miss a dose: take it when you remember, unless the next one is close; in that case just skip it. Never double up; with lithium, an extra dose isn't harmless
Keep your habits steady: roughly consistent fluid and salt intake day to day matters more with lithium than with most medicines
Tell other doctors: any doctor treating you should know you take lithium before new medicines are added

What side effects should I expect?

Most are mild, and several can be eased with a counter-medicine if they persist. Not everyone gets them.

A fine trembling of the hands
Dry mouth and thirst
Passing more urine than usual
Nausea, or loose stools
Over time, changes in thyroid function: which is why it's checked on your blood tests

If anything is bothering you, tell your doctor; there's often a way to adjust.

Finally, the one thing to know with lithium: if the level climbs too high it can cause lithium toxicity. The regular blood tests are there to catch a rising level early. Get in touch straight away if you notice:

A tremor that is clearly worse than usual
Ongoing vomiting or diarrhoea, or loss of appetite
Unsteadiness or slurred speech, or feeling unusually drowsy or confused

Will I become dependent? How do I stop safely?

No; lithium isn't habit-forming. But stopping suddenly carries a real risk of relapse, especially of mania. Any change is made gradually, with your doctor, with the blood tests continuing along the way.

Can I drive while taking it?

The Japanese label advises against driving while taking it. Lithium can cause drowsiness or dizziness in some people, and the label here instructs that patients on it shouldn't drive or operate dangerous machinery. Discuss your own situation with your doctor.

What about pregnancy and breastfeeding?

This is a conversation to have early, before pregnancy if possible. Lithium can affect the baby's developing heart, so in pregnancy it's avoided except when truly necessary. If it is continued, the Japanese label calls for care from a doctor experienced in bipolar disorder, with the lithium level checked often, because the level changes during pregnancy and can rise sharply around delivery. The Japanese label says to avoid breastfeeding while taking lithium: it passes into milk, and an infant's level can reach a third to a half of the mother's. At the same time, never stop lithium suddenly on discovering a pregnancy; sudden withdrawal risks a severe relapse, which is dangerous for both of you. The safe path is an early, planned conversation. Our guides to medication in pregnancy and medication while breastfeeding cover the wider picture.