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Lithium

Lithium is a mood stabiliser medicine available only on prescription.

Lithium may take several weeks or months to work. As long as it controls your condition, you will usually take lithium for a long time.

Types of lithium

Lithium comes as:

  • slow release tablets such as Priadel
  • a liquid such as Priadel liquid and Li-Liquid

It's important not to change types unless your doctor prescribes it.

Priadel liquid and Li-Liquid are not authorised for use in Ireland so they are not commonly used. But your doctor may prescribe them as an 'exempt medicinal product' if they think they will benefit you.

Uses of lithium

Lithium is used to treat mental health conditions such as:

  • mania - feeling highly excited or distracted
  • hypomania - similar to mania, but less severe
  • bipolar disorder - where mood changes between very high and very low
  • recurring periods of depression

Lithium can also reduce aggressive or self-harming behaviour.

If you take too much

The level of lithium in your blood should be checked regularly by your doctor.

Taking too much can cause an emergency known as lithium toxicity.

Emergency action required: Call 112 or 999 or go to an emergency department (ED) if you:

  • take more than your prescribed dose of lithium, even if you do not feel any different

Do not drive to ED. Get someone else to drive you or call for an ambulance. Bring the packet or leaflet and any remaining medicine with you.

If you take too much lithium you may:

  • have loss of appetite, feel sick (nausea) or get sick (vomit)
  • have problems with your eyesight, such as blurred vision
  • need to drink and pee more than normal
  • lack control over pee or poo
  • feel lightheaded or drowsy
  • feel confused or you're having blackouts
  • are shaking, have muscle weakness, jerks or spasms
  • have difficulty speaking

When you start taking lithium

When you start on lithium you'll have a blood test every week to make sure you're taking the right dose.

When your doctor is happy with your dose you'll have a blood test every 2 to 3 months.

If you have a lithium therapy patient information booklet, you can record your results in the lithium record book. Check with your doctor about this booklet if you do not have one.

Check if you can take lithium

Adults can take lithium. It's not recommended for children or teenagers under age 18.

Lithium may not be suitable if you:

  • had an allergic reaction to lithium or other medicines in the past
  • have heart disease
  • have severe kidney problems
  • have untreated hypothyroidism (underactive thyroid)
  • have low levels of sodium in your body
  • have Addison's disease - a rare disorder of the adrenal glands
  • you or someone in your family has a rare heart condition called Brugada syndrome
  • need to have surgery

Pregnancy and lithium

Do not take lithium if you are pregnant, especially in the first 3 months of pregnancy unless your doctor says you need it.

If you think you may be pregnant or you become pregnant unexpectedly, contact your doctor immediately. Do not stop taking lithium before speaking to your doctor.

Tell your doctor if you're trying to get pregnant. This is important.

Breastfeeding and lithium

Do not breastfeed if you are taking lithium.

Lithium passes easily to babies through breast milk, causing high levels of lithium in their blood.

Contraception and fertility

Lithium does not affect contraception.

There is no clear evidence that lithium affects female fertility. There is small chance that it reduces sperm count in men.

Tell your doctor if you're trying for a baby.

How and when to take lithium

You will usually take lithium once a day at night. This is because when you have your regular blood test, you need to have it 12 hours after taking your medicine.

Swallow tablets whole with water or juice. Do not chew them. You can take them with or without food.

If you're taking the liquid version, use the plastic syringe or spoon that comes with your medicine to measure the dose. Do not use a kitchen teaspoon as you will not get the right amount.

Do not stop taking lithium or change your dose, even if you start to feel better.

If you forget to take lithium

See the patient information leaflet that comes with your medicine for advice on what to do if you forget to take your medicine.

Non-urgent advice: Find your patient information leaflet

Your patient information leaflet is the leaflet that comes with your medicine. You can find a digital version of the leaflet online.

Priadel tablets

If you forget to take a dose, take it as soon as you remember, then go on as before.

Do not take a double dose to make up for a forgotten dose.

Side effects

If you're on the right dose you may not have any side effects when taking lithium.

However, some people find lithium slows down their thinking or makes them feel mentally numb.

Other common side effects

Other side effects are usually mild and go away by themselves. They are more likely to happen when you start taking lithium.

Keep taking the medicine but talk to your doctor if side effects get worse or do not go away after a few days.

There are things you can do to manage common side effects:

Feeling sick (nausea)

Try to stick to simple meals and do not eat rich or spicy food. It might also help to take your medicine after eating.

Getting sick (vomiting)

If you’re getting sick, take sips of water to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee.

If you take contraceptive pills and you're being sick, your contraception may not protect you from pregnancy. Check the pill packet for advice.

Diarrhoea

Drink plenty of fluids to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor.

If you take contraceptive pills and have severe diarrhoea for more than 24 hours, your contraception may not protect you from pregnancy. Check the pill packet for advice.

Dry mouth or metallic taste

Try sugar-free gum or sweets, or sipping cold drinks. If this does not help, talk to your pharmacist or doctor. Try not to have drinks with a lot of calories in as this might also mean you put on weight.

Slight shaking of your hands

Talk to your doctor if this is bothering you or does not go away after a few days. These symptoms can be a sign that the dose is too high for you. Your doctor may change your dose or recommend taking your medicine at a different time of day.

Feeling tired or sleepy

As your body gets used to lithium, these side effects should wear off. If these symptoms do not get better within 2 weeks, your doctor may either reduce your dose or increase it more slowly. If that does not work, you may need to switch to a different medicine.

Gradual weight gain

Try to eat well by having a healthy balanced diet without increasing your portion sizes. Do not snack on foods that contain a lot of calories, such as crisps, cakes, biscuits and sweets. If you feel hungry between meals, eat fruit and vegetables and low-calorie foods.

Being physically active will also help you keep your weight stable. Your doctor will usually monitor your weight while you're taking this medicine.

This is not a full list of possible side effects.

See the patient information leaflet that comes with your medicine for a full list of side effects.

Non-urgent advice: Find your patient information leaflet

Your patient information leaflet is the leaflet that comes with your medicine. You can find a digital version of the leaflet online.

Report side effects

You can report any suspected side effects to the Health Products Regulatory Authority (HPRA): report an issue - hpra.ie

Long-term side effects

Taking lithium for a long time can also cause problems with your kidneys or thyroid gland.

Common signs of an underactive thyroid are tiredness, weight gain and feeling depressed. Signs of kidney problems include swollen hands or ankles, feeling tired and short of breath, changes in your pee and feeling sick.

Tell your doctor if you get any these symptoms. Your doctor will arrange blood tests to check for any changes in your thyroid and kidneys.

Avoiding high lithium levels in your blood

Make sure that you go for the blood tests arranged by your doctor.

To keep your lithium levels steady do not reduce your salt intake suddenly. Talk to your doctor if you want to reduce the amount of salt in your diet.

Drink plenty of fluids, especially if you are doing intense exercise or have an illness that causes you to sweat or have diarrhoea. Dehydration can cause your lithium levels to go up.

Urgent advice: Contact your doctor immediately if:

  • you feel sick, are getting sick or have diarrhoea for more than 1 or 2 days

Serious allergic reaction

A serious allergic reaction (anaphylaxis) from taking lithium is rare.

Emergency action required: Call 112 or 999 or go to an emergency department (ED) if:

  • you get a rash that's itchy, red, swollen or blistered
  • you're wheezing
  • you get tightness in your chest or throat
  • you have trouble breathing or talking
  • your mouth, face, lips, tongue or throat start swelling

Taking lithium with other medicines

Always remind your doctor or pharmacist that you are on lithium before you take new medicines.

This includes medicines or supplements you can buy without a prescription. They may not be suitable to take with lithium.

Before your doctor prescribes lithium, tell them if you're taking:

  • tablets that make you pee (diuretics) such as furosemide or bendroflumethiazide
  • non-steroidal anti-inflammatory drugs (NSAIDs) for pain relief and swelling, such as aspirin, ibuprofen, celecoxib or diclofenac
  • heart or blood pressure medicine such as enalapril, lisinopril or ramipril (ACE inhibitors)
  • medicines for depression such as fluvoxamine, paroxetine or fluoxetine
  • antibiotics such as oxytetracycline, metronidazole, co-trimoxazole or trimethoprim
  • medicines for epilepsy such as carbamazepine or phenytoin

See your patient information leaflet for a full list of medicines which may interfere with lithium.

Non-urgent advice: Find your patient information leaflet

Your patient information leaflet is the leaflet that comes with your medicine. You can find a digital version of the leaflet online.

Herbal remedies or supplements

It's not known if herbal supplements are safe to take with lithium.

They're not tested in the same way as pharmacy and prescription medicines.

Recreational drugs

Using recreational drugs can affect the level of lithium in your body.

Taking MDMA (ecstasy) while you're on lithium can make you dehydrated.

Tell your doctor if you think you might take recreational drugs while you're on lithium.

Alcohol

Lithium can make you drowsy so it's best to stop drinking alcohol during the first few days of taking lithium.

If you feel OK after this, try to stick to the weekly low-risk alcohol guidelines.

Alcohol may make you dehydrated. This can increase the levels of lithium in your blood.

Fact check

This content was fact checked by a pharmacist, a GP, and the National Medication Safety Programme (Safermeds).

Page last reviewed: 9 June 2024
Next review due: 9 June 2027

This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.