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Diamox SR 250mg Prolonged-release Capsules

Active Ingredient:
ADVANZ Pharma See contact details
ATC code: 
About Medicine
The Patient Information Leaflet (PIL) is the leaflet included in the pack with a medicine.
Last updated on emc: 10 Oct 2023

Below is a text only representation of the Patient Information Leaflet (ePIL).

The text only version may be available in large print, Braille or audio CD. For further information call emc accessibility on {phone} 0800 198 5000. The product code(s) for this leaflet is: PL 12762/0145 .

Diamox SR 250mg Capsules


Diamox SR® 250mg Prolonged-release Capsules


Read all of this leaflet carefully before you start taking this medicine.

Keep this leaflet. You may need to read it again.

If you have any further questions, ask your doctor or pharmacist.

This medicine has been prescribed for you. Do not pass it on to others. It may harm them, even if their symptoms are the same as yours.

If any of the side effects become serious or if you notice any side effects not listed in this leaflet, please tell your doctor or pharmacist.

The name of your medicine is Diamox SR 250mg Prolonged-release Capsules. It will be referred to as Diamox SR Capsules for ease of use hereafter.

In this leaflet:

1. What Diamox SR Capsules are and what they are used for
2. Before you take Diamox SR Capsules
3. How to take Diamox SR Capsules
4. Possible side effects
5. How to store Diamox SR Capsules
6. Further information


Diamox SR 250mg Prolonged-release Capsules contain the active substance Acetazolamide.

This belongs to a group of medicines known as carbonic anhydrase inhibitors.

Diamox SR Capsules are used to treat, glaucoma (a condition of the eye), by reducing the pressure within the eye.

DO NOT take Diamox SR Capsules if:
  • you know you are allergic to sulphonamides, sulphonamide derivatives including
  • acetazolamide or to any of the ingredients in the capsules (listed in Section 6 at the end of this leaflet)
  • you have severe liver problems
  • you have or have ever had severe kidney problems
  • you have a particular type of glaucoma known as chronic non congestive angle closure glaucoma (your doctor will be able to advise you)
  • you have reduced function of the adrenal glands - glands above the kidneys - (also known as Addison’s disease)
  • you have low blood levels of sodium and/or potassium or high blood levels of chlorine (your doctor will advise you)
  • the person this medicine has been prescribed for is under the age of 12.

Diamox SR Capsules should not be used in children.

Speak to your doctor if any of the above applies to you.

Take special care and speak to your doctor before taking Diamox SR Capsules if:
  • you have or have ever had kidney problems such as kidney stones
  • you have lung problems such as chronic bronchitis or emphysema, which cause difficulty in breathing
  • you have diabetes or problems with your blood sugar level
  • you are over the age of 65
  • 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 doctor.

Taking other medicines:

Please tell your doctor or pharmacist if you are taking or have recently taken any other medicines, including medicines obtained without a prescription. The effects of any of these medicines may change, particularly if you are taking, or using, any of the following:

  • medicines for your heart such as cardiac glycosides (e.g. digoxin)
  • medicines to reduce blood pressure
  • medicines to thin your blood (e.g. warfarin)
  • anti-diabetic medicines to lower the sugar in your blood (e.g. metformin)
  • medicines for epilepsy or fits (in particular, phenytoin, primidone or carbamazepine or topiramate)
  • Drugs which interfere with folic acid, e.g. methotrexate, pyrimethamine, or trimethoprim
  • steroids such as prednisolone
  • aspirin and related medicines, e.g. salicylic acid or choline salicylate for mouth ulcers
  • other drugs in the group of medicines called carbonic anhydrase inhibitors (used to treat raised pressure in your eye(s))
  • amphetamines (a stimulant), quinidine (treats an irregular heart beat), methenamine (prevents urine infections) or lithium (treats severe mental problems)
  • sodium bicarbonate therapy (used to treat conditions where there is excess acid in your body)
  • ciclosporin (used after transplants to suppress the immune system).

Diamox SR Capsules may affect some medical tests. If you visit a hospital or clinic for any medical tests, you should tell the doctor concerned that you are taking Diamox SR Capsules.

Pregnancy and breast feeding:

Ask your doctor or pharmacist for advice before taking any medicines.

Diamox SR Capsules SHOULD NOT be taken if you are pregnant, think you are pregnant or are planning to become pregnant. It may be taken when breast feeding but only on the advice of the doctor.

Driving and using machines:

If Diamox SR Capsules make you feel drowsy or confused you should not drive or operate machines. Diamox SR Capsules can occasionally cause short-sightedness; if this happens and you feel that you can no longer drive safely, you should stop driving and contact your doctor.

Important information about some of the ingredients of Diamox SR Capsules:

This medicine contains the ingredient sunset yellow FCF (E110) which may cause allergic reactions.

  • Always take the number of capsules your doctor has told you to take. This information will also be on the label.
  • The usual recommended dosage is 1 or 2 capsules a day taken just before or just after a meal.
  • Diamox SR Capsules should be swallowed whole with a drink of water. Do not chew or crush the capsules.
  • The dose varies from person to person depending on their condition. If you are not sure how many capsules to take or when to take them, ask your pharmacist.
  • Before starting and during treatment your doctor will monitor your blood to check that treatment with Diamox SR Capsules is suitable for you.

Diamox SR Capsules are not recommended for use in children.

If you take more Diamox SR Capsules than you should:

Get medical help immediately, either by calling your doctor or going to the nearest hospital casualty department. Take any remaining capsules and this leaflet with you so that the medical staff knows exactly what you have taken.

If you forget to take your Diamox SR Capsules:

You should take it as soon as you remember. However, if this is within 2 hours of your next dose you should skip the missed capsule and carry on taking the rest of your capsules as usual.

DO NOT take a double dose of capsules to make up the missed dose.

If you have any further questions about these capsules, ask your doctor or pharmacist.


Like all medicines, Diamox SR Capsules can cause side effects, although not everybody gets them.

All medicines can cause allergic reactions although serious allergic reactions are very rare. Any sudden wheeziness, difficulty in breathing, swelling of the eyelids, face or lips, rash or itching (especially affecting your whole body) should be reported to a doctor immediately.

Tell your doctor immediately if you notice any of the following side effects:
  • fever, severe chills, sore throat or mouth ulcers
  • bruises or tiny red or purple spots on your skin
  • a severe condition of the skin that may affect the mouth and other parts of the body. This may progress to a severe skin reaction which starts with painful red areas, then large blisters and ends up with peeling of layers of skin, mouth, nose, eyes or genitals. This may be accompanied by fever and chills, aching muscles and generally feeling unwell
  • weakness or paralysis, and reduced muscle tone
  • you have fits
  • pain or burning when you pass urine, have difficulty in passing urine or you stop passing urine, or have blood in your urine
  • your stools are black or tarry, or if you notice blood in your stools
  • nausea, vomiting, loss of appetite, feeling generally unwell, fever, itching, yellowing of the skin and eyes, and dark color urine
  • decrease in the number of red blood cells. tiredness, headaches, being short of breath when exercising, dizziness and looking pale
  • decrease in white blood cells
  • Softening of bones when used along with drugs used to treat fits/ convulsions
  • kidney problems.

Tell your doctor as soon as possible if you notice any of the following side effects:
  • pain in your lower back
  • pale stools.
  • your skin or eyes look slightly yellow.

You may also experience the following:

Common side effects (probably occuring in less than 1 in 10 people) are

  • headache
  • diarrhoea
  • feeling or being sick, loss of appetite, thirst, or a metallic taste in the mouth
  • dizziness, loss of full control of arms or legs
  • looking flushed
  • a need to pass urine more often than normal
  • tiredness or irritability
  • feeling over-excited
  • low blood sugar
  • a tingling or numbness in the fingers or toes, or coldness in the extremities

Uncommon side effects (probably occuring in less than 1 in 100 people) are:

  • depression
  • drowsiness or confusion
  • a loss of interest in sex
  • ringing in the ears or difficulty in hearing
  • temporary short-sightedness which subsides when the dosage is reduced or treatment is stopped.
  • low Platelet count,
  • decrease in cells production responsible for providing immunity and
  • low potassium levels

If you take Diamox SR Capsules for a long time it can occasionally affect the amount of potassium, or sodium in your blood. Your doctor will probably take blood tests to check that this does not happen. You might also experience bone thinning or the risk of kidney stones with long-term therapy. High or low blood sugar levels may occasionally occur.

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 effects is not known (cannot be estimated from the available data).

If any of the side effects becomes serious, or if you notice any side effects not listed in this leaflet, please tell your doctor or pharmacist.

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:

By reporting side effects you can help provide more information on the safety of this medicine.


Store below 30 °C

Store in the original package in order to protect from light and moisture..

Keep this medicine out of the sight and reach of children.

Do not use after the expiry date. This date is printed on your pack. The Expiry date refers to last day of that month.

Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer required. These measures will help to protect the environment.


This medicine is for you. Only a doctor can prescribe it for you. Never give this medicine to someone else; it could harm them, even if their symptoms seem the same as yours.

What Diamox SR Capsules Contain:

The active substance is acetazolamide. Each capsule contains 250mg acetazolamide.

The other ingredients are microcrystalline cellulose (E460), sodium lauryl sulphate, purified water, ethyl cellulose, hydroxypropyl methylcellulose (E464), mineral oil, Pigment Blend PB-230005 Orange [hydroxy propyl cellulose, titanium dioxide and FD&C Yellow #6/Sunset Yellow FCF aluminium lake (15-18% grade), Talc and FD&C Yellow #6/Sunset yellow FCF aluminium lake (38-42% grade)].

Capsule shell contains gelatin, titanium dioxide (E171), yellow iron oxide (E172) and erythrosine (E127).

What Diamox SR Capsules look like and contents of the pack:

Diamox SR capsules have a clear body and orange cap, and are printed with ‘GS 250’ in black. They usually come in blister packs of 28 or 30 capsules, although the capsule may also be available in bottles of 28, 100 or 500. Not all pack sizes may be marketed.

Marketing Authorization Holder:
Mercury Pharmaceuticals Ltd.
Dashwood House
69 Old Broad Street
United Kingdom

Mercury Pharmaceuticals Ltd.
Dashwood House
69 Old Broad Street
United Kingdom

Alternate Manufacture:

Rottendorf Pharma GmbH
Ostenfelder Strasse 51-61
D-59320 Ennigerloh

This leaflet was last revised in August 2023.

Mercury Pharmaceuticals Ltd. is licensed to use the registered trademark Diamox SR.

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