UK Edition. Click here for US version.
ACETAZOLAMIDE TABLETS 250MG
Active substance(s): ACETAZOLAMIDE
250 mg TABLETS
Read all of this leaflet carefully before you start
taking this medicine because it contains
important information for you.
- Keep this leaflet. You may need to read it again.
- If you have any further questions, ask your doctor
or pharmacist or nurse.
- This medicine has been prescribed for you
only. Do not pass it on to others. It may harm
them, even if their signs of illness are the same as
- If you get any side effects, talk to your doctor or
pharmacist or nurse. This includes any possible
side effects not listed in this leaflet. See section 4.
WHAT IS IN THIS LEAFLET
1. What Acetazolamide is and what it is
2. What you need to know before you
3. How to take Acetazolamide
4. Possible side effects
5. How to store Acetazolamide
6. Contents of the pack and other
1. WHAT ACETAZOLAMIDE IS AND
WHAT IT IS USED FOR
Acetazolamide 250 mg Tablets contain the active
substance acetazolamide, which belongs to a group of
medicines known as carbonic anhydrase inhibitors.
Acetazolamide is used to treat:
glaucoma, a condition associated with increased
pressure in the eye
abnormal fluid retention, the build-up of fluid in the
epilepsy, a neurological condition characterised by
seizures (fits), in particular absence seizures (petit
mal), in children. If you are not sure why you have
been prescribed Acetazolamide, please ask your
2. WHAT YOU NEED TO KNOW BEFORE
YOU TAKE ACETAZOLAMIDE
DO NOT take Acetazolamide, and tell your doctor, if
if you are allergic to acetazolamide or any of the other
ingredients of this medicines (listed in section 6)
have low levels of potassium or sodium in your
have hyperchloraemic acidosis, a condition in which
the plasma becomes too acidic due to an increased
chloride concentration and/or a decreased
have liver or kidney problems
have problems with your adrenal glands (small
hormone-producing glands near the kidneys), such
as Addison’s disease
need long-term treatment for a particular type of
glaucoma known as chronic non congestive angle
Do not take this medicine if any of the above applies to
you. If you are not sure, talk to your doctor before taking
Warnings and Precautions
Talk to your doctor or pharmacist or nurse before taking
Acetazolamide if you:
have, or have previously had, kidney stones
are at greater risk of your blood becoming too acidic,
this includes if you:
- suffer from diabetes
- are over the age of 65
- have kidney problems
- have lung problems which may cause shortness of
breath, a persistent cough, wheezing or tightness
of the chest
A small number of people being treated with
anti-epileptics such as acetazolamide have had
thoughts of harming or killing themselves. If at any time
you have these thoughts, immediately contact your
Operations and tests
Taking Acetazolamide may affect the results of some
clinical tests. If you are going to have a test, it is
important to tell your doctor or nurse that you are taking
If you are taking Acetazolamide for a long time your
doctor may want you to have some blood tests to check
your blood cell counts and electrolyte levels.
Other medicines and Acetazolamide tablets:
Tell your doctor or pharmacist if you are taking, have
recently taken, or might take any other medicines,
including medicines bought without a prescription. This
is because Acetazolamide can affect the way some
medicines work, and some medicines can affect the way
In particular, tell your doctor or pharmacist if you are
taking any of the following:
any other carbonic anhydrase inhibitors for
glaucoma, such as dorzolamide or brinzolamide
other medicines to treat epilepsy or fits, such as
carbamazepine, phenytoin, phenobarbital or
medicines to treat high blood pressure, such as
captopril, enalapril (ACE inhibitors), doxazosin,
prazosin (alpha-blockers), candesartan,
losartan (angiotensin-II receptor antagonists),
clonidine, diazoxide, guanethidine, hydralazine,
methyldopa, minoxidil, moxonidine or sodium
medicines to treat diabetes, such as gliclazide,
metformin or insulin
medicines used to treat an irregular or uneven
heartbeat, or heart failure, such as quinidine or
cardiac glycosides like digoxin
aspirin to treat pain, inflammation or fever
ciclosporin to suppress the immune system and stop
the rejection of organs after transplants
lithium for mental health problems
methenamine, an anti-bacterial used to treat
sodium bicarbonate therapy used to treat high levels
of acid in the body
drugs which interfere with folic acid, e.g.
methotrexate, pyrimethamine, or trimethoprim
amphetamines, stimulants sometimes used to treat
Attention Deficit Hyperactive Disorder (ADHD)
Pregnancy and breast-feeding
If you are pregnant or breast-feeding, think you may
be pregnant or are planning to have a baby, ask your
doctor or pharmacist for advice before taking this
Do not take Acetazolamide if you are pregnant, planning
to become pregnant, or are breast-feeding, unless your
doctor has told you to. Follow your doctor’s advice.
Driving and using machines:
While taking Acetazolamide you may experience
fatigue, drowsiness, dizziness, tingling or numbness
(’pins and needles’), a lack of muscle coordination,
disorientation, or short-sightedness. If this happens, do
not drive or operate machinery, tell your doctor.
Acetazolamide contains lactose and sucrose
If you have been told by your doctor that you have an
intolerance to some sugars, contact your doctor before
taking this medicinal product.
3. HOW TO TAKE ACETAZOLAMIDE
Always take this medicine exactly as your doctor has
told you. The dose of Acetazolamide will vary from
person to person, and depend on the condition being
treated. Your doctor will decide on the most appropriate
dose for you. Check with your doctor or pharmacist if
you are not sure.
Acetazolamide tablets should be swallowed whole with
a drink of water.
The recommended doses are:
250 mg – 1000 mg (1 – 4 tablets) in a 24 hour period,
taken in divided doses for amounts over 250 mg
The typical starting dose is 250 mg – 375 mg (1 – 1½
tablets) daily in the morning, after which your doctor may
adjust the dose and/or how often you take it, depending
on your response.
A single dose of 125 mg – 375 mg (½ – 1½ tablets) daily
is recommended for fluid retention associated with
250 mg – 1000 mg (1 – 4 tablets) daily, in divided doses
Acetazolamide should be used with particular caution in
elderly patients as they are at greater risk of their blood
becoming too acidic. Follow your doctor’s advice.
Your doctor will advise you of the dose, to be taken in
divided doses, depending on your child’s bodyweight.
The dose should not exceed 750 mg (3 tablets) daily.
If you take more Acetazolamide than you should:
If you, or someone else, takes more tablets than you
should, contact your doctor or go to the nearest hospital
casualty department immediately. Take this leaflet and
the medicine pack with you, so the doctor knows what
has been taken.
Increased doses of Acetazolamide may cause
drowsiness or tingling or numbess (’pins and needles’).
If you forget to take Acetazolamide:
If you forget to take a dose, take it as soon as you
remember. However, if it is nearly time for your next
dose, skip the missed dose and take your next
scheduled dose at the correct time. Do not take a double
dose to make up for a forgotten dose.
If you have any further questions on the use of this
medicine, ask your doctor or pharmacist.
4. POSSIBLE SIDE EFFECTS
Like all medicines, this medicine can cause side effects,
although not everybody gets them.
If you get any of the following side effects, STOP
TAKING Acetazolamide and tell your doctor or go to
the nearest hospital emergency department
an allergic reaction to acetazolamide, the signs of
which can include red raised lumps (hives), rashes,
itching, swelling of the hands, feet, face, lips, tongue
or throat which may cause difficulty in swallowing or
severe skin rashes (Stevens-Johnson syndrome,
toxic epidermal necrolysis), appearing initially as
reddish target-like spots or circular patches often
with central blisters. The rash may progress to
widespread blistering or peeling of the skin
effects on the ears: hearing disturbances, ringing in
effects on the stomach and intestines: passing black
tarry stools (faeces) or blood in your stools
effects on the liver: abnormal liver function,
inflammation of the liver (hepatitis), which causes
yellowing of the skin or white of the eyes (jaundice)
effects on the kidneys: crystals in the urine
(crystalluria), which may be seen as cloudy urine or
cause difficulty in passing urine, kidney stones, pain
radiating from the kidney to the groin, damaged
kidney tissue, passing large amounts of urine, sugar
in the urine, blood in the urine, kidney failure
Contact a doctor immediately if you experience a
serious skin reaction: a red, scaly rash with bumps
under the skin and blisters (exanthematous pustulosis).
The frequency of this side effect is not known (cannot be
estimated from the available data).
If you get any of the following side effects, stop
taking Acetazolamide and tell your doctor as soon
changes to your blood such as altered numbers of
white blood cells, red blood cells or blood platelets.
This may cause symptoms including unexplained
bleeding, bruising, increased risk of infections, sore
throat, fever, weakness, breathlessness, pale skin or
general illness. A blood test can be taken to check.
temporary loss of hearing
Tell your doctor or pharmacist if you get any of the
following side effects:
Effects on the brain and central nervous system:
headache, irritability, dizziness, tingling or numbness
(‘pins and needles’), difficulty in controlling movements,
depression, confusion, drowsiness, reduced sex drive,
Effects on the eyes: temporary short-sightedness (this
will resolve when the dosage is reduced or the treatment
Effects on the stomach and intestines: feeling or
being sick, diarrhoea, some loss of appetite, thirst, taste
Effects on the skin: sensitivity of the skin to sunlight
Other general effects: fatigue, fever, flushing
Taking Acetazolamide for a long time may cause
changes to the electrolytes in your body, and can cause
your blood to become too acidic. A blood test can be
taken to check.
Reporting of side effects
If you get any side effects, talk to your doctor,
pharmacist or nurse. This includes any possible side
effects not listed in this leaflet.
You can also report side effects directly via the Yellow
Card Scheme at: www.mhra.gov.uk/yellowcard. By
reporting side effects you can help provide more
information on the safety of this medicine.
5. HOW TO STORE ACETAZOLAMIDE
Keep this medicine out of the sight and reach of
Do not use this medicine after the expiry date which is
stated on the container. The expiry date refers to the last
day of that month.
Store below 25°C. Store in the original container, and
keep the container tightly closed in order to protect from
Do not throw away any medicines via wastewater or
household waste. Ask your pharmacist how to throw
away medicines you no longer use. These measures will
help protect the environment.
6. CONTENTS OF THE PACK AND
What Acetazolamide contains:
The active substance (the ingredient which makes the
medicine work), is acetazolamide. Each tablet contains
250 mg of acetazolamide.
The other ingredients are lactose, maize starch,
pregelatinised starch, povidone, sucrose, sodium starch
glycolate and magnesium stearate.
What Acetazolamide looks like and contents of the
Acetazolamide 250 mg Tablets are round, odourless,
white biconvex uncoated tablets with crossed
score-lines on one side and plain on the other side.
They come in plastic containers of 100, 112 or 500
tablets. Not all pack sizes may be marketed.
Marketing Authorisation Holder:
Chelonia Healthcare Limited,
11 Boumpoulinas, 3rd Floor, 1060 Nicosia, Cyprus
DDSA Pharmaceuticals Limited,
84 Pembroke Road, London, W8 6NX, UK
For any information about this medicine, please contact
the Marketing Authorisation Holder.
This leaflet was last revised in 11/2017.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.