Topimax Dosage

• Dosage of Topimax in details
• Topimax interactions
• Topimax reviews

Dosage of Topimax in details

Monotherapy Use

Adults and Pediatric Patients 10 Years and Older with Partial Onset or Primary Generalized Tonic-Clonic Seizures

The recommended dose for Topimax monotherapy in adults and pediatric patients 10 years of age and older is 400 mg orally once daily. Titrate Topimax Extended-Release Capsules according to the following schedule:

Adjunctive Therapy Use

Adults (17 Years of Age and Older) - Partial Onset Seizures, Primary Generalized Tonic-Clonic Seizures, or Lennox-Gastaut Syndrome

The recommended total daily dose of Topimax Extended-Release Capsules as adjunctive therapy in adults with partial onset seizures or Lennox-Gastaut Syndrome is 200 mg to 400 mg orally once daily. The recommended total dose for adults with primary generalized tonic-clonic seizures is 400 mg orally once daily.

Initiate therapy at 25 mg to 50 mg once daily followed by titration to an effective dose in increments of 25 mg to 50 mg every week. Daily Topimax doses above 1,600 mg have not been studied.

In the study of primary generalized tonic-clonic seizures using Topimax, the assigned dose was reached at the end of 8 weeks.

Pediatric Patients (Ages 2 Years to 16 Years) - Partial Onset Seizures, Primary Generalized Tonic-Clonic Seizures, or Lennox-Gastaut Syndrome

The recommended total daily dose of Topimax Extended-Release Capsules as adjunctive therapy for pediatric patients with partial onset seizures, primary generalized tonic-clonic seizures, or seizures associated with Lennox-Gastaut syndrome is approximately 5 mg/kg to 9 mg/kg orally once daily. Begin titration at 25 mg once daily (based on a range of 1 mg/kg/day to 3 mg/kg/day) given nightly for the first week. Subsequently, increase the dosage at 1 or 2 week intervals by increments of 1 mg/kg to 3 mg/kg to achieve optimal clinical response. Dose titration should be guided by clinical outcome. If required, longer intervals between dose adjustments can be used.

In the study of primary generalized tonic-clonic seizures, the assigned dose of 6 mg/kg once daily was reached at the end of 8 weeks.

Dose Modifications in Patients with Renal Impairment

In patients with renal impairment (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.

Prior to dosing, obtain an estimated creatinine clearance (CrCl) in patients at high risk for renal insufficiency (e.g., older patients, or those with diabetes mellitus, hypertension, or autoimmune disease). CrCl can be estimated using the following equation (multiply by 0.85 for women):

Dosage Modifications in Patients Undergoing Hemodialysis

Topimax is cleared by hemodialysis at a rate that is 4 to 6 times greater than in patients with normal renal function. Accordingly, a prolonged period of dialysis may cause Topimax concentration to fall below that required to maintain an anti-seizure effect. To avoid rapid drops in Topimax plasma concentration during hemodialysis, a supplemental dose of Topimax may be required. The actual adjustment should take into account the:

• duration of dialysis period
• clearance rate of the dialysis system being used
• effective renal clearance of Topimax in the patient being dialyzed.

Laboratory Testing Prior to Treatment Initiation

Measurement of baseline and periodic serum bicarbonate during treatment with Topimax Extended-Release Capsules is recommended.

Dosing Modifications in Patients Taking Phenytoin and/or Carbamazepine

The co-administration of Topimax Extended-Release Capsules with phenytoin may require an adjustment of the dose of phenytoin to achieve optimal clinical outcome. Addition or withdrawal of phenytoin and/or carbamazepine during adjunctive therapy with Topimax Extended-Release Capsules may require adjustment of the dose of Topimax Extended-Release Capsules.

Monitoring for Therapeutic Blood Levels

It is not necessary to monitor Topimax plasma concentrations to optimize therapy with Topimax Extended-Release Capsules.

Administration Instructions

Topimax Extended-Release Capsules may be swallowed whole or may be administered by carefully opening the capsule and sprinkling the entire contents on a small amount (teaspoon) of soft food. This drug/food mixture should be swallowed immediately and not chewed or crushed. Do not store drug/food mixture for further use. Topimax Extended-Release Capsules can be taken without regard to meals.

What other drugs will affect Topimax?

Cold or allergy medicine, sedatives, narcotic pain medicine, sleeping pills, muscle relaxers, and medicine for depression or anxiety can add to sleepiness caused by Topimax. Tell your doctor if you regularly use any of these medicines, or any other seizure medication.

Tell your doctor about all other medicines you use, especially:

• lithium (Eskalith, LithoBid);
• hydrochlorothiazide (HCTZ, HydroDiuril, Hyzaar, Lopressor, Vasoretic, Zestoretic);
• metformin (Glucophage, Actoplus Met, Avandamet, Fortamet, Janumet, PrandiMet, Riomet);
• atropine (Atreza, Sal-Tropine), belladonna (Donnatal, and others), benztropine (Cogentin), dimenhydrinate (Dramamine), methscopolamine (Pamine), or scopolamine (Transderm-Scop);
• bronchodilators such as ipratropium (Atrovent) or tiotropium (Spiriva);
• bladder or urinary medications such as darifenacin (Enablex), solifenacin (Vesicare), and others;
• glaucoma medications such as acetazolamide (Diamox) or methazolamide (Neptazane); or
• other seizure medications such as carbamazepine (Carbatrol, Equetro, Tegretol), lamotrigine (Lamictal), phenytoin (Dilantin), divalproex sodium (Depakote), valproic acid (Depakene, Stavzor), or zonisamide (Zonegran).

This list is not complete and other drugs may interact with Topimax. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.

Topimax interactions

Oral Contraceptives

The possibility of decreased contraceptive efficacy and increased breakthrough bleeding should be considered in patients taking combination oral contraceptive products with Topimax. Patients taking estrogen-containing contraceptives should be asked to report any change in their bleeding patterns. Contraceptive efficacy can be decreased even in the absence of breakthrough bleeding.

Antiepileptic Drugs

Concomitant administration of phenytoin or carbamazepine with Topimax decreased plasma concentrations of Topimax.

Concomitant administration of valproic acid and Topimax has been associated with hyperammonemia with and without encephalopathy. Concomitant administration of Topimax with valproic acid has also been associated with hypothermia (with and without hyperammonemia) in patients who have tolerated either drug alone. It may be prudent to examine blood ammonia levels in patients in whom the onset of hypothermia has been reported.

Numerous AEDs are substrates of the CYP enzyme system. In vitro studies indicate that Topimax does not inhibit enzyme activity for CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2D6, CYP2E1, and CYP3A4/5 isozymes. In vitro studies indicate that immediate-release Topimax is a mild inhibitor of CYP2C19 and a mild inducer of CYP3A4. The same drug interactions can be expected with the use of Topimax.

CNS Depressants And Alcohol

Topimax is a CNS depressant. Concomitant administration of Topimax with other CNS depressant drugs or alcohol can result in significant CNS depression. Concomitant use of alcohol should be avoided.

Other Carbonic Anhydrase Inhibitors

Concomitant use of Topimax, a carbonic anhydrase inhibitor, with any other carbonic anhydrase inhibitor (e.g., zonisamide, acetazolamide or dichlorphenamide), may increase the severity of metabolic acidosis and may also increase the risk of kidney stone formation. Patients should be monitored for the appearance or worsening of metabolic acidosis when Topimax is given concomitantly with another carbonic anhydrase inhibitor.

Metformin

Topimax treatment can frequently cause metabolic acidosis, a condition for which the use of metformin is contraindicated. The concomitant use of Topimax and metformin is contraindicated in patients with metabolic acidosis.

Lithium

In patients, there was an observed increase in systemic exposure of lithium following Topimax doses of up to 600 mg per day. Lithium levels should be monitored when co-administered with high-dose Topimax.

Drug Abuse And Dependence

Controlled Substance

Topimax (Topimax) extended-release capsule is not a controlled substance.

Abuse

The abuse and dependence potential of Topimax has not been evaluated in human studies.

Dependence

Topimax has not been systematically studied in animals or humans for its potential for tolerance or physical dependence.

References

1. DailyMed. "TOPIRAMATE: DailyMed provides trustworthy information about marketed drugs in the United States. DailyMed is the official provider of FDA label information (package inserts).". https://dailymed.nlm.nih.gov/dailyme... (accessed September 17, 2018).
2. FDA/SPL Indexing Data. "0H73WJJ391: The UNique Ingredient Identifier (UNII) is an alphanumeric substance identifier from the joint FDA/USP Substance Registration System (SRS).". https://www.fda.gov/ForIndustry/Data... (accessed September 17, 2018).
3. MeSH. "Neuroprotective Agents". https://www.ncbi.nlm.nih.gov/mesh/68... (accessed September 17, 2018).

Reviews

The results of a survey conducted on ndrugs.com for Topimax are given in detail below. The results of the survey conducted are based on the impressions and views of the website users and consumers taking Topimax. We implore you to kindly base your medical condition or therapeutic choices on the result or test conducted by a physician or licensed medical practitioners.

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Information checked by Dr. Sachin Kumar, MD Pharmacology