Consumer medicine information




Brand name


Active ingredient





Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Ospolot.

What is in this leaflet

This leaflet answers some common questions about Ospolot. It does not contain all the available information. It does not take the place of talking to your doctor or pharmacist.

All medicines have risks and benefits. Your doctor has weighed the risks of you taking Ospolot against the benefits they expect it will have for you.

If you have any concerns about taking this medicine, ask your doctor or pharmacist.

Keep this leaflet with the medicine. You may need to read it again.

What Ospolot is used for

Ospolot is used to control epilepsy. Epilepsy is a condition where you have repeated seizures or fits. There are many different types of seizures, ranging from mild to severe.

This medicine belongs to a group of medicines called sulphonamides.

These medicines are thought to work by controlling brain chemicals that send signals to nerves so that seizures do not happen.

Ask your doctor if you have any questions about why this medicine has been prescribed for you. Your doctor may have prescribed it for another reason.

Before you take Ospolot

When you must not take it

Do not take Ospolot if you have an allergy to:

  • any medicine containing sulthiame
  • any of the ingredients listed at the end of this leaflet
  • any other similar medicines such as sulphonamides

Symptoms of an allergic reaction may include:

  • shortness of breath
  • wheezing or difficulty breathing
  • swelling of the face, lips, tongue or other parts of the body
  • rash, itching or hives on the skin.

Do not drink alcohol while you are being treated with Ospolot.

You should not take this medicine after the expiry date printed on the pack, or if the packaging is torn or shows signs of tampering. If it has expired or is damaged, return it to your pharmacist for disposal.

If you are not sure whether you should start taking this medicine, talk to your doctor.

Before you start to take it

Tell your doctor if you have allergies to any other medicines, foods, preservatives or dyes.

Tell your doctor if you have or have had any of the following medical conditions:

  • kidney problems
  • depression.

Tell your doctor if you are pregnant or intend to become pregnant or are breastfeeding. Your doctor can discuss with you the risks and benefits involved.

If you have not told your doctor about any of the above, tell them before you start taking Ospolot.

Taking other medicines

Tell your doctor or pharmacist if you are taking any other medicines, including any that you buy without a prescription from your pharmacy, supermarket, health food shop, naturopath or herbalist.

Some medicines and Ospolot may interfere with each other. These include:

  • other medicines used to treat fits and convulsions such as primidone and phenytoin
  • phenobarbitone, carbamazepine, lamotrigine, a medicine used to sedate people or control convulsions
  • medicines used to treat eye conditions or control convulsionssuch as carboanhydrase-inhibitors.

These medicines may be affected by Ospolot or may affect how well it works. You may need different amounts of your medicines, or you may need to take different medicines.

Your doctor and pharmacist have more information on medicines to be careful with or avoid while taking this medicine.

How to take Ospolot

Follow all directions given to you by your doctor or pharmacist carefully. It may differ from the information contained in the leaflet.

If you do not understand the instructions on the bottle, ask your doctor or pharmacist for help.

How much to take

Your doctor will tell you how many tablets you will need to take each day. This may depend on your age, your condition and whether or not you are taking any other medicines.

Your doctor may recommend that you start with a low dose of Ospolot and slowly increase the dose to the lowest amount needed to control your epilepsy.

Ask your doctor or pharmacist if you are unsure of the correct dose for you. They will tell you exactly how much to take.

Follow the instructions they give you. If you take the wrong dose, Ospolot may not work as well and your problem may not improve.

How to take it

Swallow Ospolot with a glass of water.

When to take it

Take Ospolot at about the same time each day. Taking it at the same time each day will have the best effect. It will also help you remember when to take it.

Take Ospolot immediately after a meal, at about the same time each day. If you take it on an empty stomach, it may cause a stomach upset.

How long to take it

Continue taking Ospolot for as long as your doctor tells you to. Ospolot helps control your condition, but does not cure it. Therefore you must take your medicine every day, even if you feel well.

Most anticonvulsant medicines take time to work, so do not be discouraged if you do not feel better straight away.

Do not stop taking Ospolot or lower the dosage, without checking with your doctor. Do not let yourself run out of medicine over the weekend or on holidays. Stopping this medicine suddenly may cause unwanted effects or make your condition worse. Your doctor will slowly reduce your dose before you can stop taking it completely.

If you forget to take it

If it is almost time for your next dose, skip the dose you missed and take your next dose when you are meant to.

Otherwise, take it as soon as you remember, and then go back to taking your medicine as you would normally.

Do not take a double dose to make up for the dose that you missed. This may increase the chance of you getting an unwanted side effect.

If you are not sure what to do, ask your doctor or pharmacist.

If you have trouble remembering to take your medicine, ask your pharmacist for some hints.

If you take too much (overdose)

Immediately telephone your doctor or the Poisons Information Centre (telephone 13 11 26), or go to the Accident and Emergency Department at your nearest hospital, if you think that you or anyone else may have taken too much Ospolot. Do this even if there are no signs of discomfort or poisoning. You may need urgent medical attention.

Symptoms of an overdose may include:

  • vomiting
  • headache
  • dizziness, light-headedness
  • spinning sensation
  • unsteadiness when walking
  • increased rate or abnormal breathing

While you are using Ospolot

Things you must do

If you are about to be started on any new medicine, remind your doctor and pharmacist that you are taking Ospolot.

Tell any other doctors, dentists, and pharmacists who treat you that you are taking this medicine.

If you are going to have surgery, tell the surgeon or anaesthetist that you are taking this medicine. It may affect other medicines used during surgery.

Tell your doctor if you have any changes in mood or behaviour, or have thoughts about harming yourself. This medicine may increase the risk of suicidal thoughts and behaviours.

If you become pregnant while taking Ospolot, tell your doctor immediately.

If you need to have any blood tests tell your doctor that you are taking this medicine. It may affect the results of some tests.

Keep all of your doctor’s appointments so that your progress can be checked. Your doctor may do some tests from time to time to make sure the medicine is working and to prevent unwanted side effects.

Tell your doctor if you feel Ospolot is not helping your condition. Your doctor may need to change the dose of your medicine or may need to change your medicine.

Things you must not do

Do not take Ospolot to treat any other complaints unless your doctor tells you to.

Do not give Ospolot to anyone else, even if they have the same condition as you.

Do not stop using taking your medicine or lower the dosage without checking with your doctor. If you stop taking it suddenly, your condition may worsen.

Do not drink alcohol while taking Ospolot.

Things to be careful of

Be careful driving or operating machinery until you know how Ospolot affects you. This medicine may cause dizziness in some people. If you have any of these symptoms do not drive, operate machinery or do anything else that could be dangerous.

Side effects

Tell your doctor or pharmacist as soon as possible if you do not feel well while you are taking Ospolot

This medicine helps most people with epilepsy, but it may have unwanted side effects in a few people. All medicines can have side effects. Sometimes they are serious, most of the time they are not. You may need medical treatment if you get some of the side effects.

Do not be alarmed by the following list of side effects. You may not experience any of them.

Ask your doctor or pharmacist to answer any questions you may have.

Tell your doctor or pharmacist if you notice any of the following and they worry you:

  • weakness, unsteadiness when walking, reduced co-ordination or slowed reactions
  • rapid breathing, shortness of breath, difficulty breathing
  • change in heart beat
  • changes in appetite, changes in your weight
  • numbness or tingling face, hands and feet
  • fainting.

The above list includes the more common side effects of your medicine.

Tell your doctor as soon as possible if you notice any of the following:

  • giddiness
  • skin rash
  • nausea or vomiting
  • stomach pain, cramps or discomfort
  • headache
  • double vision
  • increased saliva
  • increased pain
  • sleeplessness (insomnia)
  • unusual changes in mood or behaviour
  • symptoms of depression which may include:
    - sadness
    - loss of interest or pleasure in activities you used to enjoy
    - change in weight
    - difficulty sleeping, or oversleeping
    - energy loss
    - feelings of worthlessness
    - thoughts of death

The above list includes the less common side effects of your medicine.

Tell your doctor immediately or go to the Accident and Emergency Department at your nearest hospital if you notice any of the following:

  • suicidal thoughts, behaviour, or thoughts about self-harm
  • severe skin blisters and bleeding in the lips, eyes, mouth, nose and genitals
  • fever, severe chills, sore throat or mouth ulcers
  • more frequent or more severe seizures or fits
  • a series of rapidly repeated seizures without gaining consciousness
  • severe depression, recurrence of a previous mental illness.

These are very serious side effects. You may need urgent medical attention or hospitalisation. These side effects are very rare.

Tell your doctor or pharmacist if you notice anything that is making you feel unwell.

Other side effects not listed above may also occur in some people. Some of these side effects such as changes in the levels of calcium and vitamin D can only be found when your doctor does tests from time to time to check your progress.

After using Ospolot


Keep your tablets in the bottle until it is time to take them. If you take the tablets out of the bottle they will not keep well.

Keep your tablets in a cool dry place where the temperature stays below 30°C.

Do not store Ospolot or any other medicine in the bathroom or near a sink. Do not leave it in on a window sill or in the car. Heat and dampness can destroy some medicines.

Keep it where children cannot reach it. A locked cupboard at least one-and-a-half metres above the ground is a good place to store medicines.


If your doctor tells you to stop taking this medicine or the expiry date has passed, ask your pharmacist what to do with any medicine that is left over.

Product description

What it looks like

Ospolot 50 mg contains 50 mg tablets that are white, round, film-coated and debossed 50 on one side, plain on the reverse side.

Ospolot 200 mg contains 200 mg tablets that are white, round, film-coated and debossed 200 on one side and scored on the reverse side.

The 50 mg tablets and 200 mg tablets are supplied in HDPE bottles (200 tablets per bottle).


Ospolot 50 mg contains 50 mg of sulthiame as the active ingredient per tablet.

Ospolot 200 mg contains 200 mg of sulthiame as the active ingredient per tablet.

Both strengths also contain:

  • maize starch
  • lactose monohydrate (sugars)
  • purified talc
  • colloidal anhydrous silica
  • gelatin
  • magnesium stearate
  • hypromellose
  • macrogol 4000
  • titanium dioxide

Ospolot does not contain sucrose, gluten, tartrazine or any other azo dyes.


Ospolot® is supplied in Australia by:

Phebra Pty Ltd
19 Orion Road
Lane Cove West NSW 2066

Ospolot® 50 mg
AUST R 18847
Phebra product code TAB002

Ospolot® 200 mg
AUST R 18848
Phebra product code TAB003

This leaflet was updated in Jun 2021.

Ospolot, Phebra and the Phi symbol are registered trademarks of Phebra Pty Ltd.

Published by MIMS August 2021


Brand name


Active ingredient





1 Name of Medicine


2 Qualitative and Quantitative Composition

Ospolot film-coated tablets contain 50 mg or 200 mg of sulthiame.

Excipients of known effect.

Sugars as lactose.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Ospolot 50 mg tablets are white film-coated round tablets, debossed "50" on one side and plain on the reverse side.
Ospolot 200 mg tablets are white film-coated round tablets debossed "200" on one side and scored on the reverse side.

4 Clinical Particulars

4.1 Therapeutic Indications

Ospolot is indicated as an anticonvulsant for behavioural disorders associated with epilepsy; hyperkinetic behaviour; temporal lobe epilepsy; myoclonic seizures; grand mal attacks; Jacksonian seizures.

4.2 Dose and Method of Administration

Caution should be used when establishing dosage in the presence of renal or hepatic impairment.
Treatment should start with a low dosage which is gradually increased until clinical response is satisfactory. This may require four weeks. Ospolot tablets should preferably be swallowed whole with a little fluid after meals.


Initially 100 mg twice daily or 50 mg three times daily (optimum: 200 mg three times daily).


Initially 3-5 mg/kg daily in equal divided doses (optimum: 10-15 mg/kg daily in equal divided doses).

4.3 Contraindications

Ospolot may not be used in cases of known hypersensitivity to sulthiame, other sulfonamides or to any of the excipients listed in List of Excipients.
Sulthiame should not be used in patients with known acute porphyria, hyperthyroidism or arterial hypertension.

4.4 Special Warnings and Precautions for Use

Ospolot should be administered to patients with a history of psychiatric disorders or impaired renal function only with adequate monitoring. Sulthiame is predominantly renally excreted.

Suicidal behaviour and ideation.

Antiepileptic drugs, including sulthiame, increase the risk of suicidal thoughts or behaviour in patients taking these drugs for any indication. Patients treated with any antiepileptic drug (AED) for any indication should be monitored for the emergence or worsening of depression, suicidal thoughts or behaviour, and/or any unusual changes in mood or behaviour.
Pooled analyses of 199 placebo controlled clinical trials (mono- and injunctive therapy) of 11 different AEDs showed that patients randomised to one of the AEDs had approximately twice the risk (adjusted relative risk 1.8, 95% CI: 1.2, 2.7) of suicidal thinking or behaviour compared to patients randomised on placebo. In these trials, which had a median treatment duration of 12 weeks, the estimated incidence rate of suicidal behaviour or ideation among 27,863 AED treated patients was 0.43%, compared to 0.23% among 16,029 placebo treated patients, representing an increase of approximately one case of suicidal thinking or behaviour for every 530 patients treated. There were four suicides in drug treated patients in the trials and none in placebo treated patients, but the number is too small to allow any conclusion about drug effect on suicide.
The increased risk of suicidal thoughts or behaviour with AEDs was observed as early as one week after starting drug treatment with AEDs and persisted for the duration of treatment assessed. Because most trials included in the analysis did not extend beyond 24 weeks, the risk of suicidal thoughts could not be assessed.
The risk of suicidal thoughts or behaviour was generally consistent among drugs in the data analysed. The finding of increased risk with AEDs of varying mechanisms of action and across a range of indications suggests that the risk applies to all AEDs used for any indication. The risk did not vary substantially by age (5 - 100 years) in the clinical trials analysed. Table 1 shows absolute and relative risk by indication for all evaluated AEDs.
The relative risk for suicidal thoughts or behaviour was higher in clinical trials for epilepsy than in clinical trials for psychiatric or other conditions, but the absolute risk differences were similar for the epilepsy and psychiatric indications.
Anyone considering prescribing sulthiame or any other AED must balance this risk with the risk of untreated illness. Epilepsy and many other illnesses for which AEDs are prescribed are themselves associated with morbidity and mortality and an increased risk of suicidal thoughts and behaviour. Should suicidal thoughts and behaviour emerge during treatment, the prescriber needs to consider whether the emergence of these symptoms in any given patient may be related to the illness being treated.
Patients, their caregivers, and families should be informed that AEDs increase the risk of suicidal thoughts and behaviour and should be advised of the need to be alert for the emergence or worsening of the signs and symptoms of depression, any unusual changes in mood or behaviour, or the emergence of suicidal thoughts, behaviour, or thoughts about self harm. Behaviours of concern should be reported immediately to the treating doctor.
The patients, their caregivers, and families should be instructed to consult the attending doctor immediately if fever, sore throat, allergic skin reactions with lymph node swelling and/or flu-like symptoms occur during treatment with Ospolot. Progressive thrombocytopenias or leukopenias that are accompanied by clinical symptoms, such as fever or sore throat, require interruption of treatment. In cases of severe allergic reactions, Ospolot must be discontinued immediately. Treatment should also be interrupted if a lasting increase in creatinine occurs. The blood count, liver enzymes and urine should be checked regularly.
Patients with rare hereditary problems of galactose intolerance, lactase deficiency or glucose-galactose malabsorption should not take Ospolot.

Use in hepatic impairment.

See Section 4.2 Dose and Method of Administration.

Use in renal impairment.

Ospolot should be administered to patients with a history of impaired renal function only with adequate monitoring. Sulthiame is predominantly renally excreted.

Use in the elderly.

No data available.

Paediatric use.

See Section 4.2 Dose and Method of Administration, Children.

Effects on laboratory tests.

Sulthiame may interfere with the estimation of barbiturates in laboratory tests on blood.

4.5 Interactions with Other Medicines and Other Forms of Interactions


Alcohol must not be consumed during treatment. As sulthiame is a sulfonamide derivative, it can theoretically have a similar effect as that of disulfiram. These symptoms include a very unpleasant, although generally self limiting systemic reaction caused by vasodilatation, with pulsating headache, respiratory depression, nausea, vomiting, tachycardia, hypotension, amblyopia, confusion, shock reactions, arrhythmias, loss of consciousness and seizures. The degree and duration of these symptoms can vary to a great extent.


The concomitant use of sulthiame and primidone may lead to severe side effects, especially in children, including dizziness, unstable gait, drowsiness and psychotic reactions.


The addition of sulthiame to pre-existing phenytoin therapy is shown to be followed by a rise in the serum levels of phenytoin. It has been suggested that this may be due either to inhibition by sulthiame of the hydroxylation of phenytoin or to displacement of phenytoin from a storage site by sulthiame. Phenytoin dosage may need to be reduced when sulthiame is added. This combination requires especially strict monitoring and frequent controls of phenytoin plasma levels, particularly in the case of impaired renal function.


Sulthiame may also induce a rise in the serum level of phenobarbitone.


There are indications that sulthiame serum levels may decrease if carbamazepine is taken concomitantly.


In combination with lamotrigine, an elevation of lamotrigine levels in the blood has also been observed in individual cases. Therefore, lamotrigine levels should be checked more frequently at the beginning of such a treatment.

Carboanhydrase inhibitors.

Concomitant use of sulthiame and other carbonic anhydrase inhibitors (e.g. topiramate, acetazolamide) may increase the risk of undesirable effects due to carbonic anhydrase inhibition.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

No data available.
(Category D)
Ospolot is Pregnancy Category D - Drugs which have caused, are suspected to have caused or may be expected to cause, an increased incidence of human fetal malformations or irreversible damage. These drugs may also have adverse pharmacological effects.
The risk of a mother with epilepsy giving birth to a baby with an abnormality is about three times that of the normal population. Some of this risk is due to the anticonvulsant drugs taken. Mothers taking more than one anticonvulsant drug might have a higher risk of having a baby with a malformation than mothers taking one drug. There is a lack of data permitting any statement that women taking sulthiame are at any different risk of having a baby with an abnormality from women taking other anticonvulsants. Overall, the risk of having an abnormal child is far outweighed by the dangers to the mother and fetus of uncontrolled convulsions. If administered during pregnancy the dose of sulthiame must be kept as low as possible, particularly between days 20 and 40 of gestation.
It is not known whether sulthiame is excreted in breast milk or whether it has a harmful effect on the newborn. Therefore it is not recommended for breastfeeding mothers unless the expected benefits outweigh any potential risk.

4.7 Effects on Ability to Drive and Use Machines

The effects of this medicine on a person’s ability to drive and use machines were not assessed as part of its registration.

4.8 Adverse Effects (Undesirable Effects)

The following frequency categories are used for the evaluation of adverse effects: very common (≥ 1/10); common (≥ 1/100 to < 1/10); uncommon (≥ 1/1,000 to < 1/100); rare (≥ 1/10,000 to < 1/1,000); very rare (< 1/10,000); not known (frequency cannot be estimated from the available data).

Metabolism and nutrition disorders.

Very common: anorexia.
Common: weight loss.

Psychiatric disorders.

Uncommon: hallucinations, anxiety, lack of drive, psychic changes, depression, behavioural anomaly.

Nervous system disorders.

Common: ataxia, paraesthesias in the extremities and in the face (dose dependent), dizziness (giddiness).
Uncommon: headache, myasthenic phenomena, grand mal status, increased seizure activity, drooling, insomnia.
Not known: polyneuritis.

Eye disorders.

Common: double vision.

Cardiac disorders.

Common: stenocardia, tachycardia.

Respiratory, thoracic and mediastinal disorders.

Very common: hyperpnoea, dyspnoea.
Common: tachypnoea, singultus.

Gastrointestinal disorders.

Very common: gastric complaints (in about 10% of patients).
Uncommon: abdominal pain, nausea.

Hepatobiliary disorders.

Not known: hepatotoxic reactions, increase of liver enzymes.

Skin and subcutaneous disorders.

Uncommon: Stevens-Johnson syndrome.
Not known: rash, Lyell's syndrome.

Musculoskeletal and connective tissue disorders.

Uncommon: joint pain.

Renal and urinary disorders.

Not known: acute renal failure.

Blood and lymphatic system disorders.

Uncommon: leucopenia.
In one case, administration of Ospolot led to progressive weakness of the limbs, hypersalivation, slurred speech, increasing drowsiness up to coma. The symptoms abated within hours of Ospolot being discontinued.
Sulthiame is a carbonic anhydrase inhibitor. Therefore, undesirable effects of carbonic anhydrase inhibition, such as renal stone formation, metabolic acidosis, haemodilution and changes in serum electrolyte values, cannot be excluded during administration of sulthiame.
Disturbances in calcium and vitamin D metabolism have been occasionally reported in association with long-term anticonvulsant therapy.

Reporting suspected adverse effects.

Reporting suspected adverse reactions after registration of the medicinal product is important. It allows continued monitoring of the benefit-risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions at

4.9 Overdose

Clinical features have included vomiting, hypotension, headache, vertigo, ataxia, metabolic acidosis with hyperpnoea and catatonic state.
There is no specific antidote. Treatment consists of general supportive measures including intravenous fluids. The urine should be rendered alkaline to prevent crystalluria; forced alkaline diuresis may promote elimination of sulthiame.
There is no information on the applicability of dialysis.
For information on the management of overdose, contact the Poisons Information Centre on 131 126 (Australia).

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Mechanism of action.

The structure of sulthiame is distinct from that of other anticonvulsants. It is a cyclic sulfonamide derivative without antimicrobial activity.

Clinical trials.

No data available.

5.2 Pharmacokinetic Properties


No data available.


No data available.


No data available.


No data available.

5.3 Preclinical Safety Data


No data available.


No data available.

6 Pharmaceutical Particulars

6.1 List of Excipients

The excipients in Ospolot tablets are maize starch, lactose monohydrate, purified talc, colloidal anhydrous silica, gelatin, magnesium stearate, hypromellose, macrogol 4000 and titanium dioxide.

6.2 Incompatibilities

Incompatibilities were either not assessed or not identified as part of the registration of this medicine.

6.3 Shelf Life

In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG)1. The expiry date can be found on the packaging.
1AUST R 18847, AUST R 18848.

6.4 Special Precautions for Storage

Store below 30°C.

6.5 Nature and Contents of Container

The Ospolot 50 mg tablets and Ospolot 200 mg tablets are supplied in HDPE bottles with a PP child resistant cap (200 tablets/bottle).

6.6 Special Precautions for Disposal

In Australia, any unused medicine or waste material should be disposed of by taking to your local pharmacy.

6.7 Physicochemical Properties

Chemical name: 4-(Tetrahydro-2H-1,2-thiazin-2-yl)benzenesulfonamide- S,S-dioxide.
The molecular weight of the compound is 290.4. The molecular formula is C10H14N2O4S2.
The structure of sulthiame is distinct from that of other anticonvulsants. It is a cyclic sulfonamide derivative without antimicrobial activity.

Chemical structure.

CAS number.


7 Medicine Schedule (Poisons Standard)

Schedule 4 - Prescription Only Medicine.

Summary Table of Changes