Pharm

Topiramate

search

Topiramate, Topamax, Eprontia, Qudexy XR, Trokendi XR

  • Indications
  1. Seizure Disorder
    1. Simple Partial Seizures
    2. Complex Partial Seizures
    3. Generalized Tonic Clonic Seizures
  2. Non-Seizure Related Indications
    1. Migraine Prophylaxis
    2. Obesity Management
    3. Essential Tremor
    4. Bipolar Disorder
    5. Alcohol Dependence
  1. Adult (age >10 years old) - Standard Release
    1. Initial: 25 mg orally twice daily (consider starting 25 mg only at bedtime)
    2. Increase by 25-50 mg/day increments per week
      1. Week 2: 50 mg orally twice daily
      2. Week 3: 75 mg orally twice daily
      3. Week 4: 100 mg orally twice daily
      4. Week 5: 150 mg orally twice daily
      5. Week 6: 200 mg orally twice daily
    3. Target
      1. Adults: 400 mg/day divided twice daily
      2. Elderly: 200 mg/day divided twice daily
    4. Maximum dose: 1600 mg/day divided twice daily
      1. However, doses above 400 mg/day have not been shown to be more effective
  2. Child (age 2 to 10 years, weight based protocol) - Standard Release
    1. Initial: 1-3 mg/kg up to 25 mg orally at bedtime for 1 week
    2. Increase by 1-3 mg/kg/day to 25 to 50 mg increments per week
    3. Target range: 5-9 mg/kg/day divided twice daily
      1. Weight <11 kg: Target 75 to 125 mg orally twice daily
      2. Weight 12 to 22 kg: Target 100 to 150 mg orally twice daily
      3. Weight 23 to 31 kg: Target 100 to 175 mg orally twice daily
      4. Weight 32 to 38 kg: Target 125 to 175 mg orally twice daily
      5. Weight >38 kg: Target 125 to 200 mg orally twice daily
  3. Extended Release (Trokendi XR or Qudexy XR)
    1. Trokendi XR is approved for age >6 years
    2. Qudexy XR is approved for age >2 years
    3. Use same dosing as above, but dose daily instead of twice daily
  1. Standard Release
    1. Start 25 mg orally at bedtime
    2. Titrate weekly, starting at increase of 25 mg/day/week
      1. Week 2: Take 25 mg orally twice daily
      2. Week 3: Take 25 mg orally in am and 50 mg orally in pm
      3. Then 50 mg orally twice daily
  2. Extended Release (Trokendi XR or Qudexy XR)
    1. Use same dosing as above, but dose daily instead of twice daily
  • Dosing
  • Other Indications - Adults (not FDA approved)
  1. Essential Tremor
    1. Start 25 mg orally daily
    2. Titrate by increasing 25 mg/day/week
    3. Target: 100 mg/day divided twice daily
    4. Maximum: 400 mg/day
  2. Bipolar Disorder
    1. Start 25 to 50 mg orally daily
    2. Titrate to effective target dose
    3. Maximum: 400 mg/day
  3. Alcohol Dependence
    1. Start 25 mg orally daily
    2. Titrate by increasing 25 mg/day/week
    3. Target: 300 mg/day divided twice daily
    4. Limit duration to 14 weeks
  4. Obesity Management
    1. See Phentermine and Topiramate (Qsymia)
  • Safety
  1. Pregnancy Category D
    1. Associated with fetal malformations (esp. Cleft Lip and Palate)
    2. No increase in Autism risk (in contrast to Valproate)
      1. Hernandez-Diaz (2024) N Engl J Med 390(12):1069-79 +PMID: 38507750 [PubMed]
  2. Unknown Safety in Lactation
  • Adverse Effects
  1. Common (Dose related)
    1. Interferes with concentration and memory
      1. Refered to pejoratively by some as "Dopamax"
    2. Confusion
    3. Sedation
    4. Lethargy
    5. Dizziness
    6. Ataxia
    7. Diplopia
    8. Tremor
    9. Nervousness or Anxiety
    10. Fatigue
    11. Depression
    12. Emotional Lability
    13. Anorexia and weight loss
    14. Dyspepsia
  2. Serious
    1. Nephrolithiasis
      1. Secondary to carbonic anhydrase inhibition
    2. Narrow Angle Glaucoma
    3. Hyperammonemia with Encephalopathy
      1. Increased risk when used with Valproic Acid
    4. Hypothermia
      1. Increased risk when used with Valproic Acid
    5. Hypohidrosis and Heat Stroke risk
      1. Increased risk in children, and when combined with Anticholinergic Medications
  3. Other
    1. Hyperchloremic Non-Anion Gap Metabolic Acidosis
  • Metabolism
  1. Excreted unchanged in the urine
  2. Adjust dose if Creatinine Clearance <60 ml/min/sec
    1. Decrease dose to 50%
  3. Following Hemodialysis
    1. Consider replacement dose after Hemodialysis
  • Drug Interactions
  1. Alcohol
    1. Avoid Alcohol within 6 hours of Trokendi XR (decreases Topiramate release)
  2. CNS Depressants
    1. Potentiates CNS depression
  3. Lithium
    1. Increases Lithium levels
  4. Digoxin
    1. Increases Digoxin levels
  5. Oral Contraceptives
    1. Decreases contraceptive efficacy
  • Resources
  1. Topiramate tablets and capsules (DailyMed)
    1. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=21628112-0c47-11df-95b3-498d55d89593
  • References
  1. (2022) Presc Lett, Resource #361206, Antiseizure Medications
  2. Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 56-7
  3. Hamilton (2020) Tarascon Pocket Pharmacopoeia