Qudexy Xr

— THERAPEUTIC CATEGORIES —
  • Migraine and headache
  • Seizure disorders
PAGE CONTENTS
  • Jump to Section
  • Generic Name & Formulations
  • Indications
  • Dosage and Administration
  • Contraindications
  • Boxed Warnings
  • Warnings/Precautions
  • Pharmacokinetics
  • Interactions
  • Adverse Reactions
  • Clinical Trials
  • Note
  • Patient Counseling

    • Qudexy Xr Generic Name & Formulations

    Legal Class

    Rx

    General Description

    Topiramate 25mg, 50mg, 100mg, 150mg, 200mg; ext-rel caps.

    Pharmacological Class

    Sulfamate.

    How Supplied

    XR caps—30, 90

    Manufacturer

    Upsher-Smith Laboratories, Inc.

    Generic Availability

    YES

    Mechanism of Action

    The precise mechanisms by which topiramate exerts its anticonvulsant and preventive migraine effects are unknown; however, preclinical studies have revealed four properties that may contribute to topiramate’s efficacy for epilepsy and the preventive treatment of migraine. 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.

    Qudexy Xr Indications

    Indications

    Prophylaxis of migraine headache.

    Qudexy Xr Dosage and Administration

    Adult

    Swallow whole or may open caps and sprinkle contents on a teaspoonful of soft food. Initially 25mg once daily, increase at 1-week intervals by increments of 25mg/week to target dose of 100mg once daily. Renal impairment (CrCl <70mL/min): reduce dose by ½. Hemodialysis: may need extra dose.

    Children

    <12yrs: not established.

    Qudexy Xr Contraindications

    Not Applicable

    Qudexy Xr Boxed Warnings

    Not Applicable

    Qudexy Xr Warnings/Precautions

    Warnings/Precautions

    Discontinue if acute myopia and secondary angle-closure glaucoma syndrome occur. Consider discontinuing if other visual problems occur. Obtain baseline and periodic serum bicarbonate during therapy; consider reducing dose or discontinuing if acidosis occurs. Obtain CrCl prior to dosing in patients at high risk for renal insufficiency (eg, older age, diabetes mellitus, hypertension, autoimmune disease). Monitor on growth (during prolonged therapy), oligohidrosis, and hyperthermia esp. in children. Suicidal tendencies. Inborn errors of metabolism, reduced hepatic mitochondrial activity: increased risk of hyperammonemia; measure ammonia levels if encephalopathic symptoms occur. Discontinue at the 1st sign of a rash. Maintain adequate hydration; avoid ketogenic diets. Avoid abrupt cessation. Advise females of reproductive potential to use effective contraception during therapy. Labor & delivery. Pregnancy: risk of fetal toxicity; consider alternatives. Nursing mothers.

    Qudexy Xr Pharmacokinetics

    Absorption

    Time to peak plasma concentration: ~20 hours (after a single 200mg dose). Steady-state was reached in ~5 days.

     

    Distribution

    Plasma protein bound: 15–41%.

    Metabolism

    Topiramate is not extensively metabolized. The metabolites are formed via hydroxylation, hydrolysis, and glucuronidation.

    Elimination

    Renal (70%). Half-life: ~56 hours. Oral plasma clearance: ~20 to 30mL/min.

    Qudexy Xr Interactions

    Interactions

    Increased severity of metabolic acidosis and risk of kidney stone formation with concomitant other carbonic anhydrase inhibitors (eg, zonisamide, acetazolamide, dichlorphenamide); monitor. Phenytoin, carbamazepine reduce topiramate levels. May potentiate amitriptyline, phenytoin levels. May antagonize oral contraceptives, valproic acid, glyburide, diltiazem. CNS depression potentiated with alcohol, other CNS depressants; avoid. Hyperammonemia (w/ or w/o encephalopathy) and/or hypothermia possible with valproic acid. Caution with other drugs that interfere with temperature regulation (eg, anticholinergics, carbonic anhydrase inhibitors). Monitor lithium levels with high-dose topiramate. May be antagonized by valproic acid, lamotrigine. May be potentiated by HCTZ; may need to adjust dose. Caution with concomitant pioglitazone; monitor for adequate glycemic control.

    Qudexy Xr Adverse Reactions

    Adverse Reactions

    Paresthesia, anorexia, weight decrease, speech problems, fatigue, dizziness, somnolence, nervousness, psychomotor slowing, abnormal vision, fever, difficulty with memory, taste perversion, upper RTI, abdominal pain, diarrhea, hypoesthesia, nausea; metabolic acidosis, cognitive/neuropsychiatric reactions, kidney stones, hyperammonemia, hypothermia, increased bleeding risk, serious skin reactions (eg, SJS, TEN), decrease in bone mineral density.

    Qudexy Xr Clinical Trials

    See Literature

    Qudexy Xr Note

    Not Applicable

    Qudexy Xr Patient Counseling

    See Literature

    Qudexy Xr Generic Name & Formulations

    Legal Class

    Rx

    General Description

    Topiramate 25mg, 50mg, 100mg, 150mg, 200mg; ext-rel caps.

    Pharmacological Class

    Sulfamate.

    How Supplied

    XR caps—30, 90

    Manufacturer

    Upsher-Smith Laboratories, Inc.

    Generic Availability

    YES

    Mechanism of Action

    The precise mechanisms by which topiramate exerts its anticonvulsant and preventive migraine effects are unknown; however, preclinical studies have revealed four properties that may contribute to topiramate’s efficacy for epilepsy and the preventive treatment of migraine. 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.

    Qudexy Xr Indications

    Indications

    Initial monotherapy and adjunct in partial onset or primary generalized tonic-clonic seizures. Adjunct in Lennox-Gastaut Syndrome.

    Qudexy Xr Dosage and Administration

    Adult

    Swallow whole or may open caps and sprinkle contents on a teaspoonful of soft food. Monotherapy: initially 50mg once daily, increase at 1-week intervals by increments of 50mg/week for the first 4 weeks, then increase by 100mg/week for Weeks 5–6 to target dose of 400mg once daily. Adjunctive therapy: ≥17yrs: initially 25–50mg once daily, increase at 1-week intervals by increments of 25–50mg/week to target dose of 200–400mg once daily (partial onset seizures or Lennox-Gastaut) or 400mg once daily (primary generalized tonic-clonic seizures). Renal impairment (CrCl <70mL/min): reduce dose by ½. Hemodialysis: may need extra dose.

    Children

    Swallow whole or may open caps and sprinkle contents on a teaspoonful of soft food. <2yrs: not established. Monotherapy: 2–<10yrs: initially 25mg once daily given nightly for the 1st week, then increase to 50mg once daily in 2nd week; may increase by 25–50mg once daily each subsequent week as tolerated. Minimum maintenance dose: ≤11kg: 150mg/day; 12–31kg: 200mg/day; ≥32kg: 250mg/day; titrate over 5–7 weeks. May further titrate up to the maximum maintenance dose if tolerated and clinically indicated; see full labeling. ≥10yrs: initially 50mg once daily, increase at 1-week intervals by increments of 50mg/week for the first 4 weeks, then increase by increments of 100mg/week for Weeks 5–6 to target dose of 400mg once daily. Adjunctive therapy: 2–16yrs: initially 25mg once daily (based on range: 1–3mg/kg/day) given nightly for the 1st week, increase at 1- or 2-week intervals by increments of 1–3mg/kg/day to target range of 5–9mg/kg once daily or until optimal clinical response; usual max 400mg/day. Renal impairment (CrCl <70mL/min): reduce dose by ½. Hemodialysis: may need extra dose.

    Qudexy Xr Contraindications

    Not Applicable

    Qudexy Xr Boxed Warnings

    Not Applicable

    Qudexy Xr Warnings/Precautions

    Warnings/Precautions

    Discontinue if acute myopia and secondary angle-closure glaucoma syndrome occur. Consider discontinuing if other visual problems occur. Obtain baseline and periodic serum bicarbonate during therapy; consider reducing dose or discontinuing if acidosis occurs. Obtain CrCl prior to dosing in patients at high risk for renal insufficiency (eg, older age, diabetes mellitus, hypertension, autoimmune disease). Monitor on growth (during prolonged therapy), oligohidrosis, and hyperthermia esp. in children. Suicidal tendencies. Inborn errors of metabolism, reduced hepatic mitochondrial activity: increased risk of hyperammonemia; measure ammonia levels if encephalopathic symptoms occur. Discontinue at the 1st sign of a rash. Maintain adequate hydration; avoid ketogenic diets. Avoid abrupt cessation. Advise females of reproductive potential to use effective contraception during therapy. Labor & delivery. Pregnancy: risk of fetal toxicity; consider alternatives. Nursing mothers.

    Qudexy Xr Pharmacokinetics

    Absorption

    Time to peak plasma concentration: ~20 hours after a single 200mg dose of Qudexy XR. Steady-state was reached in ~5 days.

    Distribution

    Plasma protein bound: 15–41%.

    Metabolism

    Topiramate is not extensively metabolized. The metabolites are formed via hydroxylation, hydrolysis, and glucuronidation.

    Elimination

    Renal (70%). Half-life: ~56 hours. Oral plasma clearance: ~20 to 30mL/min.

    Qudexy Xr Interactions

    Interactions

    Increased severity of metabolic acidosis and risk of kidney stone formation with concomitant other carbonic anhydrase inhibitors (eg, zonisamide, acetazolamide, dichlorphenamide); monitor. Phenytoin, carbamazepine reduce topiramate levels. May potentiate amitriptyline, phenytoin levels. May antagonize oral contraceptives, valproic acid, glyburide, diltiazem. CNS depression potentiated with alcohol, other CNS depressants; avoid. Hyperammonemia (w/ or w/o encephalopathy) and/or hypothermia possible with valproic acid. Caution with other drugs that interfere with temperature regulation (eg, anticholinergics, carbonic anhydrase inhibitors). Monitor lithium levels with high-dose topiramate. May be antagonized by valproic acid, lamotrigine. May be potentiated by HCTZ; may need to adjust dose. Caution with concomitant pioglitazone; monitor for adequate glycemic control.

    Qudexy Xr Adverse Reactions

    Adverse Reactions

    Paresthesia, anorexia, weight decrease, speech problems, fatigue, dizziness, somnolence, nervousness, psychomotor slowing, abnormal vision, fever, difficulty with memory, taste perversion, upper RTI, abdominal pain, diarrhea, hypoesthesia, nausea; metabolic acidosis, cognitive/neuropsychiatric reactions, kidney stones, hyperammonemia, hypothermia, increased bleeding risk, serious skin reactions (eg, SJS, TEN), decrease in bone mineral density.

    Qudexy Xr Clinical Trials

    See Literature

    Qudexy Xr Note

    Not Applicable

    Qudexy Xr Patient Counseling

    See Literature

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