Topamax 25
Topamax 25 Uses, Dosage, Side Effects, Food Interaction and all others data.
Topamax 25 is a sulfamate-substituted monosaccharide, related to fructose. Topamax 25 is quickly absorbed after oral use. Topamax 25 enhances GABA-activated chloride channels. In addition, topiramate inhibits excitatory neurotransmission, through actions on kainate and AMPA receptors. Topamax 25 has a specific effect on GluR5 kainate receptors. It is also an inhibitor of carbonic anhydrase, particularly subtypes II and IV, but this action is weak and unlikely to be related to its anticonvulsant actions, but may account for the bad taste and the development of renal stones seen during treatment. Its possible effect as a mood stabilizer seems to occur before anticonvulsant qualities at lower dosages.
Topamax 25 prevents the occurrence of seizures and prevents migraine symptoms by reducing neural pathway excitability. It is important to note that this drug may cause metabolic acidosis, mood changes, suicidal thoughts and attempts, as well as kidney stones. When topiramate is combined with valproic acid, it is known to cause hypothermia.
| Trade Name | Topamax 25 |
| Availability | Prescription only |
| Generic | Topiramate |
| Topiramate Other Names | Tipiramate, Tipiramato, Topiramate, Topiramato, Topiramatum |
| Related Drugs | Emgality, Trokendi XR, Reyvow, gabapentin, propranolol, clonazepam, lamotrigine, diazepam, atenolol, pregabalin |
| Weight | 25mg |
| Type | Tablet |
| Formula | C12H21NO8S |
| Weight | Average: 339.362 Monoisotopic: 339.098787343 |
| Protein binding | Topiramate is not highly bound to plasma proteins, with an estimated plasma protein binding of 9-17% according to some studies. The FDA label indicates that the protein binding of topiramate is 15-41%. |
| Groups | Approved |
| Therapeutic Class | Adjunct anti-epileptic drugs |
| Manufacturer | Cilag Ag |
| Available Country | Switzerland, Nigeria |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
This drug is used to treat epilepsy in both children and adults. In children it is also used for treatment of Lennox-Gastaut syndrome (a disorder that causes seizures and developmental delay). It is now most frequently prescribed for the prevention of migraines. It has been used by psychiatrists to treat bipolar disorder and alcoholism.
The drug is also used to treat Post Traumatic Stress Disorder. Studies suggest that Topamax 25 is effective against infantile spasms.
Monotherapy in Epilepsy: Topamax 25 is used for initial monotherapy in patients of 10 years of age and older with partial onset or primary generalized tonic-clonic seizures.
Adjunctive Therapyin Epilepsy: Topamax 25 is used for adjunctive therapy for adults and pediatric patients ages 2-16 years with partial onset seizures, or primary generalized tonic-clonic seizures, and in patients 2 years of age and older with seizures associated with Lennox-Gastaut syndrome.
Migraine: Topamax 25 is used for adults for the prophylaxis of migraine headache.
Topamax 25 is also used to associated treatment for these conditions: Alcohol Dependency, Grand mal Generalized tonic-clonic seizure, Lennox-Gastaut Syndrome (LGS), Migraine, Moods Disorders, Partial-Onset Seizures, Weight, Primary generalized tonic-clonic seizure Epilepsy, Weight Reduction
How Topamax 25 works
A seizure is an abnormal and unregulated electrical discharge occurring in the brain. This leads to transient interruption in brain function, manifested by reduced alertness, abnormal sensations, and focal involuntary movements or convulsions. Several types of seizures exist, with common types including tonic-clonic seizures and partial onset seizures.
The exact mechanisms by which topiramate exerts pharmacological actions on seizures and migraines are currently not fully characterized. Several properties of this drug, however, are likely to contribute to its therapeutic effects. Topamax 25 has been observed to exert actions on voltage-dependent sodium channels, GABA receptors, and glutamate receptors.
Topamax 25 stimulates GABA-A receptor activity at brain non-benzodiazepine receptor sites and reduces glutamate activity at both AMPA and kainate receptors. Normally, GABA-A receptors are inhibitory and glutaminergic receptors are stimulatory for neuronal activity. By increasing GABA activity and inhibiting glutamate activity, topiramate blocks neuronal excitability, preventing seizures and migraines. Additionally, it blocks the voltage-dependent sodium channels, further blocking seizure activity. Topamax 25 has been shown to inhibit various carbonic anhydrase isozymes, but the clinical significance of this is unknown at this time.
Dosage
Topamax 25 dosage
The initial dose normally is low and increased in slow steps.The usual initial dose is 25 to 50 mg daily in 2 single doses. Recommended increments are 25 to 50 mg every 1 or 2 weeks. Common doses for maintenance treatment are 100 to 200 mg daily. The highest dose possible is 1,000 mg daily in divided doses.
Monotherapy Use: The recommended maximum dose for Topamax 25 monotherapy in adults and children 10 years of age and older is 400 mg/day in two divided doses.
Adjunctive Therapy Use Adults (17 Years of Age and Over): The recommended total daily dose of Topamax 25 is 400 mg/day in Partial Seizures or Primary Generalized Tonic-Clonic Seizures. Daily doses above 1600 mg have not been studied.
Pediatric Patients (Ages 2 to 16 Years): Partial Seizures or Primary Generalized Tonic-Clonic Seizures The recommended total daily dose of Topamax 25 tablets as adjunctive therapy for patients with partial seizures or primary generalized tonic-clonic seizures is approximately 5 to 9 mg/kg/day in two divided doses.Titration should begin at 25 mg (or less, based on a range of 1 to 3 mg/kg/day) nightly for the first week. The dosage should then be increased at 1 or 2 week intervals by increments of 1 to 3 mg/kg/day (administered in two divided doses), to achieve optimal clinical response. Dose titration should be guided by clinical outcome.
Topamax 25 tablets can be taken without regards to meals.
Side Effects
The most common side effects include a change in taste and feelings of pins and needles in the head and extremities. Less common side effects include cognitive deficiency (particularly word-finding difficulty); difficulty in understanding, grogginess, lethargy, renal (kidney) stones, vision abnormality, weight loss, breast pain, abdominal pain, intense sweating, menstrual disorder and dry mouth.
Toxicity
The LD50 of intraperitoneal topiramate in the rat is above 1500 mg/kg.
Overdose information
In a study of 4 healthy adult women taking topiramate, the severity of clinical effects following an overdose ranged from asymptomatic to severe, with no deaths reported. According to the FDA prescribing information for topiramate, an overdose may cause hypotension, severe metabolic acidosis, coma, abdominal pain, visual disturbances, convulsions, drowsiness, speech abnormalities, impaired mentation and coordination, stupor, agitation, dizziness, as well as depression.
In the case of a recent ingestion of topiramate, the stomach contents should be emptied through the induction of emesis or gastric lavage. Offer supportive treatment, including activated charcoal and hemodialysis.
Precaution
Concomitant administration of Topamax 25 and valproic acid has been associated with hyperammonemia with or without encephalopathy in patients who have tolerated either drug alone. In patients who develop unexplained lethargy, vomiting, or changes in mental status, hyperammonemic encephalopathy should be considered and an ammonia level should be measured.
Interaction
Potential interactions between Topamax 25 and standard AEDs like Phenytoin, Carbamazepine and Valproic acid were observed during the concomitant treatment with these drugs for antiepileptic patients. Beside these. Concomitant use of Topamax 25, a carbonic anhydrase inhibitor, with other carbonic anhydrase inhibitors, e.g., acetazolamide or dichlorphenamide, may create a physiological environment that increases the risk of renal stone formation. Digoxin, CNS depressants, oral contraceptives. Hydrochlorothiazide (HCTZ) may also interact with Topamax 25.
Food Interaction
- Avoid a ketogenic diet. This type of diet increases the risk of kidney stones.
- Take with or without food. Food slightly alters absorption but not to any clinically significant extent.
Topamax 25 Alcohol interaction
[Moderate] GENERALLY AVOID:
Topamax 25, when coadministered with other CNS depressants including alcoholic beverages, may lead to excessive somnolence and other forms of nervous system depression.
The patient should be informed to avoid alcohol or to use caution if these agents are coadministered, especially if performing hazardous tasks such as driving or operating machinery.
Topamax 25 Drug Interaction
Major: aripiprazole, diphenhydramineModerate: duloxetine, escitalopram, pregabalin, acetaminophen / hydrocodone, alprazolam, sertraline, cetirizineUnknown: amphetamine / dextroamphetamine, omega-3 polyunsaturated fatty acids, albuterol, montelukast, levothyroxine, cyanocobalamin, ascorbic acid, ergocalciferol, cholecalciferol, lisdexamfetamine, bupropion
Volume of Distribution
The mean apparent volume of distribution of topiramate ranges from 0.6-0.8 L/kg when doses of 100mg to 1200mg are given. Topamax 25 readily crosses the blood-brain barrier.
Elimination Route
After a 400mg dose in one clinical trial, topiramate reached maximal concentrations within 1.8-4.3 hours and ranged from 1.73-28.7 ug/mL. Food did not significantly affect the extent of absorption, despite delaying time to peak concentration. In patients with normal creatinine clearance, steady state concentrations are reached within 4 days. The bioavailability of topiramate in tablet form is about 80% compared to a topiramate solution.
Half Life
The elimination half-life is reported to be in the range of 19-23 hours. If topiramate is given with enzyme-inducers, the half-life can be reduced to 12-15 hours because of increased metabolism.
Clearance
The mean oral plasma clearance of topiramate ranges from 22-36 mL/min while the renal clearance is 17-18 mL/min, according to one pharmacokinetic study. The FDA label for topiramate indicates a similar oral plasma clearance of approximately 20 to 30 mL/min in adults.
Elimination Route
Topamax 25 is mainly eliminated through the kidneys. About 70-80% of the eliminated dose is found unchanged in the urine.
Pregnancy & Breastfeeding use
Topamax 25 is pregnancy category C. So it may be given only if clearly needed and after the assessment of risk benefit ratio. It is not known whether Topamax 25 is excreted through breast milk. So caution should be taken if it is prescribed to a breast feeding mother.
Contraindication
Topamax 25 tablets are contraindicated in patients with a history of hypersensitivity to any component of this product.
Special Warning
Patients with Renal Impairment: In renally impaired subjects (creatinine clearance less than 70 ml/min/1.73 m2), one-half of the usual adult dose is recommended. Such patients will require a longer time to reach steady-state at each dose.
Patients Undergoing Hemodialysis: Topamax 25 is cleared by hemodialysis at a rate that is 4 to 6 times greater than a normal individual. Accordingly, a prolonged period of dialysis may cause Topamax 25 concentration to fall below that required to maintain an anti-seizure effect.To avoid rapid drops in Topamax 25 plasma concentration during hemodialysis, a supplemental dose of Topamax 25 may be required. The actual adjustment should take into account 1) the duration of dialysis period, 2) the clearance rate of the dialysis system being used, and 3) the effective renal clearance of Topamax 25 in the patient being dialyzed.
Acute Overdose
Overdoses of Topamax 25 includes convulsions, drowsiness, speech disturbance, blurred vision, diplopia, lethargy, abnormal coordination, stupor, hypotension, abdominal pain, agitation, dizziness and depression.The clinical consequences are not severe. Topamax 25 overdose results in severe metabolic acidosis.
In acute Topamax 25 overdose, if the ingestion is recent, the stomach should be emptied immediately by lavage or by induction of ernes is. Activated charcoal has been shown to adsorb Topamax 25 in vitro. Hemodialysis is an effective means of removing Topamax 25 from the body.
Storage Condition
Store at a cool & dry place, protected from light and moisture. Keep out of reach of the children.
Innovators Monograph
You find simplified version here Topamax 25
Topamax 25 contains Topiramate see full prescribing information from innovator Topamax 25 Monograph, Topamax 25 MSDS, Topamax 25 FDA label
FAQ
What is Topamax 25 used for?
Topamax 25 is a medicine used to treat epilepsy. These are also called anti-epileptic medicines. It can also be taken to prevent migraine. This medicine is only available on prescription.
How safe is Topamax 25?
Topamax 25 is safe for long-term use when taken as prescribed. However, several common and potentially severe side effects have been reported by a small number of patients. There are also quite a few drugs that can cause harmful interactions or become ineffective when taken in conjunction with Topamax 25.
How does Topamax 25 work?
Topamax 25 works by reducing the spread of seizure activity in the brain and restoring the normal balance of nerve activity.
What are the common side effects of Topamax 25?
Common side effects of Topamax 25 include feeling sleepy, dizziness, diarrhoea and feeling sick. These are usually mild and go away by themselves.
Is Topamax 25 safe during pregnancy?
If you take Topamax 25 during pregnancy, there is a higher risk that your baby will develop a cleft lip and cleft palate. Oral clefts happen early in pregnancy, before many women even know they are pregnant.
Is Topamax 25 safe during breastfeeding?
Topamax 25 passes into breast milk. Babies usually have very low levels of Topamax 25 in their systems, and side effects or harmful effects in the nursing baby are rarely reported.
Can I drink alcohol with Topamax 25?
Because Topamax 25 can cause mental and psychological side effects, it's not recommended that you drink alcohol while taking Topamax 25.
Can I drive after taking Topamax 25?
Do not drive a car or operate machinery until you know how this medication affects you. if you are taking Topamax 25 to control seizures, you should know that you may continue to have seizures during your treatment.
When is the best time to take Topamax 25?
You can take Topamax 25 at any time of day, but try to take your doses at the same time each day. Try to space your doses evenly through the day. For example, first thing in the morning and in the evening. Topamax 25 tablets can be taken with or without food.
Is Topamax 25 safe to take long term?
Yes, many people take Topamax 25 safely for many months or years.
What does Topamax 25 do to the brain?
Topamax 25 decrease abnormal excitement in the brain. Among other actions,Topamax 25 affects the activity of the neurotransmitter gamma-aminobutyrate.
Is Topamax 25 good for anxiety?
Topamax 25 isn't approved to treat anxiety. However, the drug may sometimes be used off-label to treat people with certain anxiety disorders, such as obsessive-compulsive disorder.
Should I take Topamax 25 at night or in the morning?
Topamax 25 is usually taken with or without food once a day in the morning. Topamax 25 may cause difficulty falling asleep or staying asleep if it is taken in the evening. Take phentermine and Topamax 25 at around the same time every day.
Can Topamax 25 cause a stroke?
Hypohidrosis is one of the described side effects of Topamax 25, and it can contribute to the development of heart stroke in patients taking this drug.
Can Topamax 25 cause heart problems?
Topamax 25 can increase your resting heart rate.
How fast will I lose weight on Topamax 25?
It can take some time to see weight loss results from taking Topamax 25. Some people may not notice a difference until they've taken the drug for at least four months, while other people may start to lose weight in their first month of taking it. Weight loss results from topiramate are proven to increase over time.
How long does it take Topamax 25 to get out of my system?
Topamax 25 stays in your system between four and six days after your last dose, depending on your personal factors such as dosage and metabolism.
Is Topamax 25 hard on the liver?
Topamax 25 is thought to be rarely associated with liver injury and by and large known to cause liver toxicity in conjunction with other anticonvulsants.
Is Topamax 25 bad for my kidneys?
Topamax 25 can increase the level of acid in your blood . This can weaken your bones, cause kidney stones, or cause growth problems in children .
Does Topamax 25 cause chest pain?
Chest pain is a previously undocumented potential side effect of Topamax 25.
Is Topamax 25 an anti inflammatory?
Topamax 25 modulates post-infarction inflammation primarily by targeting monocytes or macrophages.
Will Topamax 25 effect my fertility?
Topamax 25 for 4 weeks did not have much effect on fertility.
Can I take Topamax 25 long time ?
Topamax 25 usually takes a couple of weeks for it to work. If taking Topamax 25 to prevent migraines, it can take up to 3 months for it to work fully.
What happen If I stop Topamax 25 suddenly ?
If you suddenly stop taking Topamax 25, you may have severe seizures, even if you have not had seizures in the past. Your doctor will probably decrease your dose gradually.
What happens if I overdose?
An overdose of topiramate can be fatal.
Overdose can cause drowsiness, agitation, depression, double vision, thinking problems, problems with speech or coordination, fainting, and seizure.
