Lithium (Lithium salts) — Patient Information

Lithium is a medicine used mainly to treat certain mood disorders, helping to stabilise mood over time. Because it affects the body’s balance of salts and can build up in the bloodstream, lithium requires careful dosing, regular monitoring, and awareness of interactions with other medicines and everyday substances.

This page explains how lithium works, how it behaves in the body, how it is typically taken, safety considerations, and what to discuss with your healthcare team. Information is written to be patient-friendly for people in the United Kingdom.

Basic product information

• Active ingredient: Lithium (usually as lithium carbonate or lithium citrate, depending on the product).
• Medicine type: Mood stabiliser.
• Common dosage forms: Tablets/capsules and some liquid formulations (brand dependent).
• Manufacturer and brand: Varies by product; examples include lithium carbonate brands.
• How it is supplied: In the UK, lithium products are generally supplied via pharmacies under appropriate clinical governance and monitoring arrangements.

Different lithium preparations (and different strengths) are not always interchangeable. Always follow the specific instructions on your label and those provided by your healthcare professional.

How lithium works (mechanism of action)

The exact way lithium produces its mood-stabilising effects is complex and not fully understood. However, lithium is believed to:

• Affect brain signalling: Lithium influences several cellular pathways involved in mood regulation.
• Modulate neurotransmitter activity: It may change the release and action of certain brain chemicals.
• Influence neuronal resilience: Lithium can affect cell survival and adaptability in parts of the brain.
• Alter “second messenger” pathways: It interferes with signalling processes inside cells that help regulate mood-related behaviours.

Importantly, lithium’s therapeutic effect often builds gradually. Some people notice early changes, but full mood stabilisation can take time.

Pharmacokinetics (how lithium moves through the body)

Understanding pharmacokinetics helps explain why monitoring is needed and why interactions can matter. Key points:

• Absorption: Lithium is absorbed in the gastrointestinal tract. Absorption can vary slightly between individuals.
• Distribution: Lithium distributes into body fluids and tissues, including the brain. It does not bind strongly to proteins.
• Elimination: Lithium is removed mainly by the kidneys. This means kidney function strongly affects lithium levels.
• Half-life: Lithium’s half-life is typically around ~18–24 hours in adults (can vary). With impaired kidney function, elimination can slow and lithium may accumulate.
• Time to steady levels: Because it accumulates, steady therapeutic levels are reached after several days, depending on dosing and individual clearance.
• Therapeutic range: Therapeutic and toxic effects can overlap. That is why blood level monitoring is essential.

Any factor that changes kidney function, body water, or salt balance may change lithium levels.

Typical use in the UK

Lithium is most commonly used for mood disorders where long-term stabilisation is important. In practice, it may be used for:

• Bipolar disorder, particularly for preventing episodes (maintenance treatment) and reducing relapse risk.
• Recurrent mood episodes where mood swings are severe or difficult to control with other strategies.
• Augmentation of treatment in certain cases, as advised by a specialist, when additional mood stabilisation is needed.

Your healthcare professional will determine whether lithium is suitable based on your history, symptoms, kidney and thyroid function, current medicines, and your ability to attend regular monitoring.

Indications (what lithium is used for)

Indications can vary slightly depending on the specific lithium product and local clinical guidance. In general, lithium is indicated for:

• Maintenance treatment of bipolar disorder (to prevent recurrence of manic and depressive episodes).
• Acute mania in some settings, where rapid mood stabilisation is required and specialist assessment supports its use.

Lithium may be considered when the benefits of mood stabilisation outweigh the risks, particularly in patients who have responded to lithium previously.

How to take lithium: timing and routine

Your dose and timing will be tailored to you. Many people are prescribed either once daily or divided doses, depending on the product and clinical plan.

General timing guidance

• Take at the same time(s) each day to keep levels stable.
• Do not change your schedule without advice, especially if you monitor lithium levels.
• Blood test timing matters: if you are instructed to test “trough” levels (lowest level before the next dose), follow the schedule your clinic provides.

If you miss a dose

• Take the missed dose only if you are not close to the next scheduled dose.
• If it is almost time for the next dose, skip the missed dose and continue as normal.
• Do not double up to make up for a missed dose.

If you miss doses repeatedly, contact your healthcare team for advice—dose changes and blood tests may be needed.

Dosing (typical approach)

Lithium dosing must be individualised. The safest approach uses: weight, age, kidney function, symptom history, and blood lithium levels.

Because lithium can become toxic if levels are too high, many clinicians adjust dose to reach a target blood concentration (often described as a therapeutic range). The exact target depends on the treatment phase (maintenance vs acute), your age, and whether side effects occur.

Typical titration pattern (generalised)

• Start low and increase gradually to reach target levels.
• Check blood levels after dose adjustments, once steady state is likely to be reached.
• Review kidney/thyroid tests periodically.

Do not use “average doses” from others. The right dose for you depends on your lab results and how your body handles lithium.

Food interactions

Lithium does not usually have major interactions with specific foods in the way some medicines do, but hydration and salt intake can affect lithium levels. In addition, gastrointestinal side effects (such as nausea or diarrhoea) can alter fluid balance.

• Consistent salt and hydration: Try to keep fluid intake and dietary salt patterns consistent.
• Dehydration matters: Vomiting, severe diarrhoea, or not drinking can raise lithium levels.
• Low-salt diets: Sudden major changes in salt intake can increase lithium levels in some people.

If you have been told to follow a special diet (for example, for blood pressure), discuss it with your clinician—medication adjustment may be needed.

Alcohol interactions

Alcohol does not have a simple, single “direct” interaction with lithium for all people, but it can contribute to dehydration, sleep pattern changes, and impaired judgement. These can indirectly increase risk.

• Avoid binge drinking and aim for moderate intake, if appropriate for you.
• Stay well hydrated, especially if you drink alcohol in warm conditions.
• Extra caution: If you become dehydrated or unwell after alcohol (e.g., vomiting/diarrhoea), contact your healthcare team promptly.

If you are unsure about safe alcohol intake for your situation, ask your pharmacist or clinician.

Interactions with other medicines (including OTC products)

Interactions are a major reason lithium requires monitoring. Many drugs can increase lithium levels or change kidney clearance. Always tell your healthcare professional and pharmacist about all medicines you take, including over-the-counter products and supplements.

Common medicines that may increase lithium levels

• Non-steroidal anti-inflammatory drugs (NSAIDs) (e.g., ibuprofen, naproxen, diclofenac) in certain circumstances.
• Diuretics (water tablets), particularly thiazide diuretics.
• ACE inhibitors (for blood pressure/heart conditions), such as lisinopril or enalapril.
• Angiotensin receptor blockers (ARBs), such as losartan or candesartan.
• Some medicines affecting sodium and water balance, including certain blood pressure or heart medications.

Other possible considerations

• Dehydrating illnesses: fever with poor intake, gastroenteritis, or heavy sweating can raise lithium levels.
• Other mood medicines: Combining lithium with other psychiatric medicines may increase certain side effects in some people; adjustment may be required.
• Herbal products: Some supplements could affect kidney function or hydration; ask before starting new products.

Key rule: Do not start, stop, or change the dose of any interacting medicine without checking first. If you need pain relief, ask a pharmacist which option is safest for you.

Safety profile: important risks and side effects

Lithium can cause side effects, particularly early on or if levels become too high. The risk is reduced by careful dosing and regular blood tests. If you notice symptoms of toxicity, seek medical help promptly.

Common side effects

• Thirst and increased urination
• Fine hand tremor
• Nausea, stomach discomfort
• Diarrhoea or stomach upset
• Weight gain in some people
• Fatigue or mild drowsiness

Less common but important effects

• Thyroid changes (underactive thyroid is possible). Regular thyroid blood tests may be advised.
• Kidney effects (including reduced concentrating ability). Kidney function monitoring is important.
• Persistent or worsening tremor or coordination problems.

Signs of lithium toxicity (seek urgent advice)

Toxicity can develop if lithium levels rise too high, often due to dehydration, drug interactions, overdose, or kidney impairment. Symptoms can range from mild to severe.

• Early signs: worsening tremor, diarrhoea, vomiting, increasing drowsiness, unusual fatigue, slurred speech.
• More serious signs: confusion, severe unsteadiness, muscle twitching, seizures, or reduced consciousness.

If you suspect lithium toxicity or you develop severe symptoms, contact urgent medical services or a clinician immediately.

Practical use tips to stay safe

• Attend scheduled blood tests: levels, kidney function, and often thyroid tests.
• Keep consistent fluid intake: avoid dehydration and aim for steady day-to-day hydration.
• Maintain consistent salt intake: sudden changes in low-salt diets can raise lithium levels.
• Be cautious during illness: if you have vomiting, severe diarrhoea, high fever, or are not drinking well, contact your healthcare team for advice about lithium.
• Check other medicines: confirm NSAID use, diuretics, blood pressure medicines, and cough/cold remedies with a pharmacist.
• Use a medication routine: alarms, pill organisers, and a note of when your blood test is due help reduce missed doses.
• Report new symptoms early: increased thirst, tremor changes, coordination problems, or feeling “not yourself” should be discussed promptly.

Recent guidance and UK monitoring considerations

Clinical practice in the UK generally emphasises:

• Regular monitoring of lithium blood levels (timed according to dosing schedule).
• Monitoring kidney function (e.g., creatinine/eGFR and other relevant measures).
• Monitoring thyroid function, as thyroid impairment can occur.
• Reviewing interactions and hydration status especially when patients become unwell or start new medicines.
• Individualising target ranges based on age, comorbidities, and clinical goals.

Recommendations can evolve as new evidence emerges. Your clinician may tailor the frequency of tests and target ranges to your circumstances. If you are unsure what your monitoring plan is, ask your healthcare team or pharmacist.

Delivery and availability in the United Kingdom

Lithium products may be available from licensed pharmacies operating in the UK. Availability can depend on product strength, formulation, and supplier stock. Delivery options, dispatch times, and eligibility may vary between pharmacies and depends on regulatory requirements and local service arrangements.

• Check product availability: Some strengths or formulations may be subject to intermittent supply.
• Packaging and labelling: Your order should arrive in secure packaging with clear instructions.
• Temperature considerations: Store lithium as directed on the label (typically at room temperature away from moisture and heat).

If you need help finding the correct formulation (for example, lithium carbonate vs another salt), contact the pharmacy before placing an order.

Market/legal context for the UK

In the UK, lithium medicines are regulated and typically used under structured clinical monitoring due to the narrow range between effective and harmful levels. Medicines supply may involve additional checks by pharmacy staff to support safe use, including guidance on:

• Confirming the correct product strength and formulation.
• Ensuring monitoring is in place (blood tests and relevant safety assessments).
• Reviewing interactions based on your current medicine list.

For patients, this means you may be asked questions about your health conditions, kidney function, thyroid history, and other medicines. This is intended to support safe use rather than delay necessary care.

Alternative options (if lithium is not suitable)

Alternatives depend on your diagnosis, symptom pattern, and previous response. For bipolar disorder and mood stabilisation, clinicians may consider:

• Other mood stabilisers (e.g., certain anti-epileptic medicines used for mood stabilisation).
• Antipsychotic medicines for some mood episodes and relapse prevention in selected people.
• Psychological and lifestyle approaches alongside medication (e.g., routine support, sleep regularity, stress management).

If you are thinking about alternatives, discuss them with your specialist. Stopping lithium suddenly can lead to worsening mood symptoms, and any change should be planned carefully with monitoring.

How to store lithium

• Store according to the label: keep in the original container.
• Keep out of reach of children.
• Protect from moisture and heat.
• Do not use after expiry date.

Overdose and emergencies

Accidental overdose or misuse can be dangerous. If overdose is suspected—particularly if you develop vomiting, drowsiness, confusion, or tremor—seek urgent medical help. Keep the medicine pack available for healthcare professionals.

Summary table: key points at a glance

FAQ

1) Why does lithium need blood tests?

Lithium can build up because it is eliminated by the kidneys. The effective dose and the toxic dose are close enough that monitoring blood levels helps keep you within a safe range.

2) How long does lithium take to work?

Some people notice changes earlier, but mood stabilisation often develops gradually over days to weeks. For maintenance, the goal is relapse prevention over longer periods.

3) Can I take lithium with ibuprofen or other painkillers?

NSAIDs such as ibuprofen may increase lithium levels in some situations. It is important to ask a pharmacist what pain relief is safest for you before using NSAIDs regularly or at higher doses.

4) What should I do if I get diarrhoea or vomiting?

Loss of fluids can raise lithium levels. Contact your healthcare team promptly for advice. They may recommend adjusting or temporarily stopping lithium depending on your situation and your monitoring plan.

5) Does caffeine affect lithium?

There is no universal “rule” that caffeine directly changes lithium levels for everyone. However, caffeine can affect hydration and sleep, which can influence mood stability. Keep intake consistent and discuss concerns with your clinician.

6) Can I drink alcohol while taking lithium?

Alcohol is not an automatic “do not use,” but it can increase dehydration risk and affect judgement and sleep. If you choose to drink, keep to moderate amounts and stay well hydrated. Seek advice if you have been told to avoid alcohol.

7) Is lithium safe for people with kidney problems?

Kidney function is crucial for lithium safety. If you have reduced kidney function, your clinician may avoid lithium or use a lower dose with closer monitoring, depending on the risks and benefits.

8) Can I take lithium if I have thyroid disease?

Lithium can affect thyroid function, so people with thyroid conditions may need closer thyroid monitoring. Tell your healthcare provider about any history of hypothyroidism or hyperthyroidism.

9) What symptoms suggest lithium toxicity?

Possible signs include worsening tremor, vomiting or diarrhoea, severe drowsiness, confusion, slurred speech, or major unsteadiness. If these occur, especially if you are unwell or dehydrated, get urgent medical advice.

10) Are there any lifestyle tips that make lithium safer?

Yes: keep hydration and salt intake consistent, avoid dehydration during illness, take doses at the same time(s) daily, and attend regular blood tests. Also inform your healthcare team about any new medication or supplement.

Important: This information is for general guidance. Individual suitability, dosing, monitoring frequency, and targets can differ between people. If you have questions about your lithium regimen, interactions, or symptoms, speak to a qualified healthcare professional or pharmacist.