What is the typical dosage of carbamazepine (Extended Release) 100 MG Oral Tablet?

Carbamazepine Extended Release 100 MG Oral Tablet Dosing

Initial Dosing for Adults and Adolescents Over 12 Years

For epilepsy, start carbamazepine extended release at 200 mg twice daily (400 mg/day total), then increase by up to 200 mg/day at weekly intervals using a 3-4 times daily regimen until optimal seizure control is achieved. 1

• Maximum daily dose should not exceed 1,000 mg in patients aged 12-15 years 1
• Maximum daily dose should not exceed 1,200 mg in patients over 15 years 1
• Doses up to 1,600 mg daily have been used in adults in rare instances 1
• Maintenance dosing typically ranges from 800-1,200 mg daily once seizures are controlled 1

Initial Dosing for Children Ages 6-12 Years

• Start at 100 mg twice daily (200 mg/day total) 1
• Increase at weekly intervals by adding up to 100 mg/day using a 3-4 times daily regimen 1
• Maximum daily dose generally should not exceed 1,000 mg 1
• Maintenance dosing typically ranges from 400-800 mg daily 1

Initial Dosing for Children Under 6 Years

• Start at 10-20 mg/kg/day divided into 2-3 doses 1
• Increase weekly to achieve optimal clinical response, administered 3-4 times daily 1
• Maintenance dosing should remain below 35 mg/kg/day 1
• No safety data exists for doses above 35 mg/kg/24 hours 1

Trigeminal Neuralgia Dosing

• Start at 100 mg twice daily (200 mg/day total) 1
• May increase by up to 200 mg/day using increments of 100 mg every 12 hours as needed for pain control 1
• Maximum daily dose is 1,200 mg 1
• Maintenance dosing ranges from 400-800 mg daily for most patients, though some require as little as 200 mg or as much as 1,200 mg daily 1
• Attempt dose reduction or discontinuation at least every 3 months throughout treatment 1

Alternative Indication: Painful Diabetic Neuropathy

• Dosing ranges from 200-800 mg/day for neuropathic pain management 2

Critical Dosing Principles

Gradual titration starting with low doses minimizes side effects, which occur in approximately 58% of patients but are predominantly mild and transient. 3

• Always administer medication with meals 1
• The short half-life (10-20 hours during chronic therapy) necessitates divided dosing at least twice daily to avoid excessive peak levels 4, 5
• Once adequate control is achieved, reduce dosage gradually to the minimum effective level 1

Therapeutic Monitoring Requirements

• Target therapeutic blood level is 4-8 mcg/mL (equivalent to 15-40 μmol/L) 3, 6, 7, 5
• Draw carbamazepine levels 4-6 days after dosing or dose adjustments to avoid falsely elevated results from transient elevations 3, 6
• Baseline complete blood count and liver function tests are required before initiating therapy 3, 6
• Monthly liver function monitoring for the first 3 months, then every 3-6 months if stable 3, 6

Mandatory Pre-Treatment Screening

HLA-B*15:02 screening must be performed before initiating carbamazepine in patients of Asian descent to assess Stevens-Johnson syndrome risk. 3, 6

Common Pitfalls to Avoid

• Avoid drawing levels too soon after dosing—wait 4-6 days to prevent making decisions based on transient elevations 3, 6
• Do not use single daily dosing due to the drug's relatively short half-life, which would cause excessive peak levels and side effects 4, 5
• Provide contraceptive counseling as carbamazepine significantly decreases oral contraceptive effectiveness through hepatic enzyme induction 6
• Monitor for benign leukopenia (occurs in ~18% of patients) which typically does not require therapy discontinuation 8
• Watch for aplastic anemia (rare but potentially fatal), most likely to occur within the first 3-4 months of therapy 4

Combination Therapy Considerations

• When adding carbamazepine to existing anticonvulsant therapy, introduce it gradually while maintaining or gradually decreasing other anticonvulsants 1
• Exception: phenytoin may need to be increased when combined with carbamazepine 1
• Phenytoin and phenobarbital induce carbamazepine metabolism, potentially requiring higher doses 7, 5