Consumer medicine information

1. Why am I using TOPAMAX?

TOPAMAX contains the active ingredient topiramate. TOPAMAX is used for the treatment of various types of seizures in adults and children, aged 2 years and over. It can also be used for the prevention of migraines in adults.
For more information, see Section 1. Why am I using TOPAMAX? in the full CMI.

2. What should I know before I use TOPAMAX?

Do not use if you have ever had an allergic reaction to topiramate or any of the ingredients listed at the end of the CMI.
Talk to your doctor if you have any other medical conditions, take any other medicines, or are pregnant or plan to become pregnant or are breastfeeding.
For more information, see Section 2. What should I know before I use TOPAMAX? in the full CMI.

3. What if I am taking other medicines?

Some medicines may interfere with TOPAMAX and affect how it works.
A list of these medicines is in Section 3. What if I am taking other medicines? in the full CMI.

4. How do I use TOPAMAX?

• Epilepsy (adults): Treatment starts at a low dose of 25 mg to 50 mg per day. The dose is then gradually increased by 25 mg to 100 mg over weekly periods or longer, until the most suitable dose is reached.

• Epilepsy (children 2 years and over): Treatment starts at 25 mg or less per day, depending on the body weight. This dose is then gradually increased over weekly periods or longer, until the most suitable dose is reached.

• Migraine (adults): Treatment starts at a low dose of 25 mg nightly for one week. The dose is then increased over weekly periods or longer by 25mg/day, until the most suitable dose is reached.

5. What should I know while using TOPAMAX?

6. Are there any side effects?

Like all medicines, TOPAMAX can cause side effects, although not everybody gets them. Your doctor will discuss potential side effects with you and will explain the risks and benefits of your treatment. Some side effects can be serious, and you may require urgent medical attention.
For more information, including what to do if you have any side effects, see Section 6. Are there any side effects? in the full CMI.

1 Name of Medicine

Topiramate.

2 Qualitative and Quantitative Composition

Topamax 25 mg, 50 mg, 100 mg and 200 mg film-coated tablets. Each tablet contains 25 mg, 50 mg, 100 mg or 200 mg of topiramate.
Excipient(s) with known effect. Sugars as lactose.
For a full list of excipients, see Section 6.1 List of Excipients.
Topamax sprinkle 15 mg, 25 mg and 50 mg hard capsules. Each capsule consists of sugar spheres enclosed in a gelatin capsule. The sugar spheres contain 15 mg, 25 mg or 50 mg of topiramate.
Excipient with known effect. Sugars.
For a full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Tablets. Topamax film-coated tablets are supplied in blisters:
25 mg, round and white, marked "TOP" on one side and "25" on the other;
50 mg, round and light-yellow, marked "TOP" on one side and "50" on the other;
100 mg, round and yellow, marked "TOP" on one side and "100" on the other;
200 mg, round and salmon, marked "TOP" on one side and "200" on the other.
Capsules. Topamax Sprinkle capsules contain small, white to off-white spheres and are supplied in bottles. Each capsule consists of a clear capsule cap and a white capsule body:
15 mg, imprinted "TOP" on cap and "15 mg" on body;
25 mg, imprinted "TOP" on cap and "25 mg" on body;
50 mg, imprinted "TOP" on cap and "50 mg" on body.

4 Clinical Particulars

4.9 Overdose

Signs and symptoms. Ingestion of between 6 and 40 g topiramate have been reported in a few patients. Signs and symptoms included headache, agitation, drowsiness, lethargy, convulsions, speech disturbances, blurred vision, diplopia, mentation impaired, abnormal coordination, stupor, hypotension, abdominal pain, dizziness, depression and hypokalaemia. The clinical consequences were not severe in most cases, but deaths have been reported after polydrug overdoses involving topiramate.
Topiramate overdose can result in severe metabolic acidosis (see Section 4.4 Special Warnings and Precautions for Use, Metabolic acidosis and sequelae).
The highest topiramate overdose reported was calculated to be between 96 and 110 g and resulted in coma lasting 20 to 24 hours followed by full recovery after 3 to 4 days.
Treatment. In the event of overdose, Topiramate should be discontinued and general supportive treatment given until clinical toxicity has been diminished or resolved. Haemodialysis has been shown to be an effective means of removing topiramate from the body. The patient should be well hydrated.
For information on the management of overdose, contact the Poisons Information Centre on 131126 (Australia).

5 Pharmacological Properties

5.3 Preclinical Safety Data

Genotoxicity. Topiramate was not genotoxic in a series of assays for gene mutations, chromosomal damage or DNA damage.
Carcinogenicity. No evidence of carcinogenicity was seen in rats following oral administration of topiramate for 2 years at doses of 120 mg/kg/day. An increased incidence of urinary bladder tumours of a proliferative nature was observed in mice following oral administration of topiramate for 22 months at doses of 300 mg/kg/day. These tumours probably resulted from chronic irritation and may lack clinical significance. The plasma concentration exposure obtained in the animal studies was less than the likely clinical exposure at the maximum recommended dose.

6 Pharmaceutical Particulars

6.7 Physicochemical Properties

Chemical structure.
https://stagingapi.mims.com/au/public/v2/images/fullchemgif/CSTOPIRA.gif CAS number. 97240-79-4.
Topiramate [2,3:4,5-bis-O-(1-methylethylidene)-beta-D-fructopyranose sulfamate] is a white crystalline powder with a bitter taste. It is most soluble in alkaline solutions containing sodium hydroxide or sodium phosphate and has a pH of 9 to 10. It is freely soluble in acetone, chloroform, dimethylsulfoxide and ethanol. The solubility in water is 9.8 mg/mL. Its saturated solution has a pH of 6.3.

7 Medicine Schedule (Poisons Standard)

S4 - Prescription Only Medicine.

Summary Table of Changes

https://stagingapi.mims.com/au/public/v2/images/fulltablegif/TOPAMAST.gif