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Written by Dr Adrian Lloyd, lecturer and honorary specialist registrar in psychiatry
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| Lithium can stabilise mood swings and boost the effect of
antidepressants |
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Lithium is a medicine that is used to treat mood
disorders:
-
depression where mood
is severely low.
-
bipolar affective disorder
(manic depression) in which mood is excessively high on some occasions
and very low on others.
It is a simple chemical (in some ways similar to salt) that
occurs naturally. Lithium has been used for more than 50 years, so doctors and
many patients are familiar with it.
The forms of lithium used medically are lithium carbonate, and
lithium citrate. The following are all brands of lithium:Camcolit (lithium carbonate),
Li-liquid (lithium
citrate),
Liskonum (lithium
carbonate),
Priadel tablets (lithium
carbonate) and
Priadel liquid (lithium
citrate).
What is lithium used for?
There are different ways in which lithium is used.
To treat mania (high mood with overactivity, racing thoughts
and agitation)
Lithium needs to be taken in doses that keep its level in the
blood relatively high. Often, other medicines are used initially to treat mania
because of the increased risk of side effects with high levels of lithium, and
because it takes a number of days to work. Lithium is then introduced a little
later to stabilise mood.
As a mood stabiliser
To help prevent the recurrence of severe swings in mood,
after an acute episode of bipolar illness has settled. Lithium may take several
weeks, months and probably up to two years to reach its full potential effect
as a mood stabiliser. Even if lithium does not completely stop the mood swings,
it usually reduces their severity.
To boost the effect of antidepressants
When
antidepressant medications have not
worked fully in treating depression, adding lithium can be a very good way of
increasing their effectiveness and getting the symptoms to improve.
How does lithium work?
It is not really known how lithium works. Lithium may alter the
way that nerve cells respond to some of the chemicals that pass messages
between them. However, it is known that it is a very effective medicine.
How often is lithium taken?
Mostly, it is taken as a single dose at night - this is more
convenient and reduces the problems with some of the side effects.
A few people may find it is better to split the total amount
into more than one dose - follow your doctor's advice.
Is lithium addictive?
Lithium is not addictive. But when it is stopped, it should be
reduced gradually to minimise the chances of the illness coming back.
Is lithium a safe medicine?
Lithium is safe if used correctly, according you your
specialist's or family doctor's instructions.
-
Before you are started on lithium, your doctor will need to
know your medical history - including any psychiatric illnesses you have had in
the past.
-
Your doctor will examine you physically and take a blood sample
to check your blood count, your kidney function and your thyroid gland.
-
Depending on your medical history your doctor may also ask you
to collect urine for 24 hours and arrange for you to have an ECG heart tracing
done. These tests are simply to make sure that it safe for you to start taking
lithium.
The problem with lithium is that a certain level of the drug has
to be produced in the blood for it to be effective, but if the level rises too
much, unpleasant and potentially serious side effects can occur.
How can I be sure that the lithium level is right?
The body gets rid of lithium through the kidneys in the urine,
and it is easy to test the lithium level in the blood.
-
After starting lithium, it takes about five days for the
lithium to build up to a steady level in the blood. For this reason your doctor
will take a blood sample to check the level about five days after you first
start to take the lithium. If the level is not quite right, the doctor can
easily work out from the blood test what the dose should be.
-
Lithium blood tests need to be taken at least 12 hours after
the last dose of lithium to make sure the test is reliable.
-
Any time a change is made in the dose, the level has to be
checked about five days later.
-
The lithium level will be checked quite frequently to begin
with until it is certain that the level is stable and correct. Once this has
been achieved, the frequency of blood tests will be less, but a test should
still be carried out about every two to three months.
-
Lithium is one of the medicines where it is important to
always take the same brand. Even at the same doses, different brands will give
different blood levels. If the brand has to be changed, a close eye will have
to be kept on the level until it is steady again.
Who will prescribe lithium and do the blood tests?
Lithium is normally first prescribed by a specialist - a
psychiatrist - who would usually do the initial blood tests. Subsequent blood
tests and changes in dose may be done by the psychiatrist, or possibly by your
family doctor in liaison with the psychiatrist. It all depends on what is the
best arrangement for the individual patient.
Many hospital outpatient departments also run specialist
lithium clinics to take care of blood tests and dosage.
What do I have to do when a blood test is due?
For the blood test to be reliable, it must be taken at least 12
hours after the last dose of lithium. This works out quite well for people who
take their lithium at night.
If you take it in the morning and at night, you will need to
miss out the morning dose on the day of the blood test to make sure it is 12
hours since you last had any lithium.
What are the side effects of lithium?
The commonest side effects that people may notice when they
start lithium are:
-
dry mouth
-
a metallic taste
-
a slight shakiness
-
a feeling of mild weakness
-
some bowel looseness (diarrhoea).
These usually settle as your body adapts to the medication.
After taking lithium for some time, the following may be
noticed:
-
weight gain.
-
passing urine more often and needing to drink more than usual.
If this happens, you should tell your the doctor.
-
swollen ankles due to water retention.
-
the thyroid gland may become underactive (see
below).
Occasionally, some people feel that they get mild memory
problems due to lithium. It is possible that this is due to the mental illness
itself, but the lithium may sometimes be responsible.
These problems generally disappear if lithium is reduced or
stopped. If they occur, your doctor will be able to advise how they should be
handled.
Less commonly, when a person has been taking lithium for some
time it can cause the thyroid gland to become underactive. This can lead to
symptoms such as:
-
a lack of energy
-
feeling the cold more
-
weight gain
-
feeling depressed.
It is important to know what a person's thyroid level is like
prior to starting lithium; any change due to the treatment can then be picked
up right away and corrected before it causes problems.
Thyroid levels need to be checked every six months. The test can
be done on the same sample that is taken for the lithium level, so there is
normally no need for any extra blood to be taken.
How are thyroid problems treated if they do occur?
If there is a problem with the thyroid gland, it is usually
reversible if the lithium can be reduced or stopped. This may be possible if
you have been free of mood swings for some time, or if it seems that one of the
alternatives to lithium might work.
If it is clear that the lithium is going to be essential to
help keep control of your illness, it is possible to give the hormone the
thyroid gland normally produces (thyroxine) as a tablet.
Make sure you discuss all the options carefully with your
doctor.
What if the lithium level gets too high?
If the lithium level gets too high, it can be potentially
dangerous and will produce some severe and unpleasant effects - this is what is
often called 'lithium toxicity'.
The warning signs of this are:
-
lack of appetite
-
diarrhoea
-
vomiting
-
blurred vision.
Diarrhoea and vomiting can make things worse by causing loss of
body fluid that concentrates the blood, increasing the lithium level.
More severe lithium excess can lead to:
-
a marked tremor (shakiness)
-
unsteadiness
-
slurred speech
-
drowsiness
-
confusion.
As the level gets even higher the person may experience:
-
muscle twitches
-
more severe drowsiness and confusion
-
fits
-
unconsciousness.
If anyone on lithium starts to experience any of these symptoms
- even the mild ones - it is essential they see a doctor immediately.
Similarly, if a person taking lithium develops any illness that
causes vomiting or diarrhoea, stops them from eating or drinking normally, or
develops a fever that leads to excessive sweating, they should see a doctor
straight away because dehydration can increase the level of lithium in the
blood.
Other medicines can also affect the level of lithium; it is
essential to always tell any doctor or pharmacist that you are taking lithium
before you buy, or are prescribed, any other medicines.
However, most people on lithium do not have problems with
toxicity.
What can I do to avoid high lithium levels developing?
-
Make sure that you go for the blood tests whenever they are
needed.
-
Don't suddenly change the amount of salt in your diet; it is
especially important not to suddenly reduce your salt intake.
-
Make sure that you drink enough fluids, especially if you are
exercising heavily or in hot weather when you will sweat more.
-
Remember that alcoholic drinks can make you lose water overall.
This is particularly important to bear in mind if you are on holiday abroad:
you may feel like drinking more alcohol, and the weather may be hot so you
sweat more.
-
See a doctor straight away if you get any of the physical
illnesses or symptoms listed above. Always tell any doctor or pharmacist that
you are taking lithium before you are prescribed, or buy, any new medicines.
How long will I have to take lithium for?
Lithium has a preventative effect when taken in the medium to
long term.
-
Lithium is mostly taken for at least one to two years to derive
full benefit from its use. Many people need to stay on it long-term to prevent
the illness relapsing.
-
When lithium is stopped, it should be tailed off gradually over
a number of weeks or months to avoid a period of mania that can occur if it is
stopped suddenly.
What about pregnancy and breastfeeding?
There is some evidence for lithium causing abnormalities in
babies whose mothers have been taking it while they are pregnant.
Clearly, it is best avoided in pregnancy. Anyone taking lithium,
who is considering getting pregnant, must discuss with their doctor the risks
involved in staying on the drug versus the risks to their own health in
stopping it.
Lithium gets into breast milk in quite high concentrations,
therefore mothers taking it should bottlefeed their babies.
Are there any alternatives to lithium?
There are alternatives to lithium, but which one depends on why
lithium is being used in the first place; the alternatives may not be as
effective as lithium. These options need to be discussed with the doctor who is
looking after you.
If you have a
bipolar
(manic-depressive) that goes through the cycle of mood changes very
frequently (rapid cycling bipolar affective disorder), lithium is not the first
choice of treatment. Often a medication called
sodium valproate
or a similar one, valproate semi-sodium (Depakote), is used
instead.
There are other situations in which other drugs are more
suitable, but for most people lithium is the best choice.
How effective is lithium?
Despite the potential difficulties with lithium treatment, it
remains the best medication for stabilising mood in most people.
It is the mood-stabilising drug that has the best-proven
results in boosting the effect of antidepressants.
Many people find it an effective medicine that helps to control
their mood disorder and greatly improve their quality of life.
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Last updated 27.03.2007
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