General Information

Qudexy XR is an extended-release formulation of topiramate, an anticonvulsant.

Qudexy XR is specifically indicated as initial monotherapy in patients 10 years of age and older with partial onset or primary generalized tonic-clonic seizures and adjunctive therapy in patients two years of age and older with partial onset or primary generalized tonic-clonic seizures and as adjunctive therapy in patients two years of age and older with seizures associated with Lennox-Gastaut syndrome.

Mechanism of Action

Qudexy XR is an extended-release formulation of topiramate. The precise mechanisms by which topiramate exerts its anticonvulsant effects are unknown; however, preclinical studies have revealed four properties that may contribute to topiramate's efficacy for epilepsy. Electrophysiological and biochemical evidence suggests that topiramate, at pharmacologically relevant concentrations, blocks voltage-dependent sodium channels, augments the activity of the neurotransmitter gamma-aminobutyrate at some subtypes of the GABA-A receptor, antagonizes the AMPA/kainate subtype of the glutamate receptor and inhibits the carbonic anhydrase enzyme, particularly isozymes II and IV.

Side Effects

Adverse events associated with the use of Qudexy XR may include, but are not limited to, the following:

Paresthesia

Anorexia

Weight decrease

Fatigue

Dizziness

Somnolence

Nervousness

Psychomotor slowing

Difficulty with memory

Difficulty with concentration/attention

Cognitive problems

Confusion

Mood problems

Fever

Infection

Flushing

Dosing/Administration

Qudexy XR is supplied as a capsule for oral administration. The recommended dose is as follows:

Monotherapy
Adults and pediatric patients 10 years and older with partial onset or primary generalized tonic-clonic seizures
400 mg orally once daily. Titrate according to the following schedule:
Week 1 50 mg once daily
Week 2 100 mg once daily
Week 3 150 mg once daily
Week 4 200 mg once daily
Week 5 300 mg once daily
Week 6 400 mg once daily

Adjunctive Therapy
Adults (17 Years of age and older) with partial onset seizures, primary generalized tonic-clonic seizures or Lennox-Gastaut syndrome
The recommended total daily dose of Quedexy XR 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.
Pediatric patients (ages two years to 16 years) with partial onset seizures, primary generalized tonic-clonic seizures, or Lennox-Gastaut syndrome
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 one- or two-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.