What are the preferred antiepileptic drugs and their dosing regimens for various patient groups, such as adults with focal seizures, adults with generalized tonic‑clonic seizures, children, pregnant women, and elderly patients?

Ideal Antiepileptic Drugs and Dosing by Patient Category

Adults with Focal Seizures

For adults with newly diagnosed focal epilepsy, use lamotrigine, levetiracetam, or carbamazepine as first-line monotherapy 1. These agents have Level B-C evidence for efficacy and are appropriate initial choices.

Specific Drug Selection:

• Lamotrigine: Preferred for women of childbearing age due to favorable safety profile 2, 3

  • Start 25 mg daily for 2 weeks, then 50 mg daily for 2 weeks, then increase by 50-100 mg every 1-2 weeks
  • Target: 200-400 mg/day in divided doses

• Levetiracetam: First choice when rapid titration needed and no psychiatric history 4, 2

  • Start 500 mg twice daily, increase by 500 mg every 2 weeks
  • Target: 1000-3000 mg/day in divided doses

• Carbamazepine: Preferred for men without drug interaction concerns 2, 3

  • Start 200 mg twice daily, increase by 200 mg every week
  • Target: 800-1200 mg/day in divided doses

Avoid carbamazepine in elderly patients due to high interaction potential and increased adverse effects 2.

Alternative Options:

• Oxcarbazepine, lacosamide, zonisamide, gabapentin (especially elderly) have Level A evidence as alternatives 1, 5

---

Adults with Generalized Tonic-Clonic Seizures

For generalized epilepsy with tonic-clonic seizures, use lamotrigine or levetiracetam as first-line therapy 2, 6. Valproate is highly effective but contraindicated in women of childbearing potential.

Drug Selection Algorithm:

For men or postmenopausal women:

• Valproate (most effective, Level C-D evidence) 6
  • Start 500 mg twice daily, increase by 250-500 mg every 3-7 days
  • Target: 1000-2500 mg/day in divided doses
  • Avoid if: weight concerns, insomnia, headache, cognitive issues

For women of childbearing age:

• Lamotrigine (Level C evidence) 2, 6
  • Start 25 mg daily for 2 weeks, then 50 mg daily for 2 weeks, then increase by 50 mg every 1-2 weeks
  • Target: 200-500 mg/day in divided doses

For patients with psychiatric comorbidities:

• Levetiracetam (Level C evidence) - use cautiously if mood disorder history 2, 6
  • Start 500 mg twice daily, increase by 500 mg every 2 weeks
  • Target: 1000-3000 mg/day

Alternative:

• Topiramate (effective but cognitive concerns) 6
• Perampanel (promising newer option) 6

---

Children with Epilepsy

Focal Seizures in Children:

Use gabapentin, lamotrigine, oxcarbazepine, or topiramate 7. All have evidence for adjunctive treatment of refractory partial seizures in children.

• Oxcarbazepine: Level A evidence in children (though single trial) 2
• Lamotrigine: Broad spectrum, suitable for multiple seizure types
• Levetiracetam: Rapid titration, good safety profile 8

Generalized Epilepsy in Children:

Lamotrigine and topiramate are effective for idiopathic generalized epilepsy 7.

Absence Seizures (Childhood Absence Epilepsy):

Use ethosuximide or valproic acid before lamotrigine (Level B) 1.

• Ethosuximide: First choice for absence without GTC (Level A) 2
• Valproic acid: When GTC also present
• Lamotrigine: Third-line option

Lennox-Gastaut Syndrome:

Lamotrigine and topiramate have limited evidence for efficacy 7.

---

Pregnant Women

Achieve seizure control with monotherapy at minimum effective dose 9.

Critical Recommendations:

• Avoid valproic acid - highest teratogenic risk 9
• Avoid polytherapy 9
• Add folic acid supplementation routinely 9
• Preferred agents: Lamotrigine, levetiracetam (based on lower teratogenic risk)
• Breastfeeding is safe with phenobarbital, phenytoin, carbamazepine, valproic acid 9

---

Elderly Patients

For elderly patients (≥60 years), use lamotrigine or gabapentin (Level B-C evidence) 1.

Specific Considerations:

• Gabapentin: May be considered for focal epilepsy (Level C) 1
• Lamotrigine: Should be considered (Level B) 1
• Levetiracetam: Favorable due to no drug interactions 4
• Avoid carbamazepine: High interaction potential, accelerates metabolism of cardiovascular drugs, worsens hyperlipidemia, increases osteoporosis risk 4
• Avoid enzyme-inducing AEDs (phenytoin, carbamazepine) in patients with coronary/cerebrovascular disease 4

---

Status Epilepticus (Emergency Setting)

First-Line Treatment:

Benzodiazepines (lorazepam preferred over diazepam if IV access available) 9.

Second-Line Treatment (Refractory Status After Benzodiazepines):

Level B Recommendation: Use IV phenytoin, fosphenytoin, or valproate 10.

Dosing:

• Fosphenytoin: 20 mg PE/kg IV at max rate 150 mg PE/min 10
• Phenytoin: 20 mg/kg IV at max rate 50 mg/min 10
• Valproate: Up to 30 mg/kg IV at max rate 10 mg/kg/min 10

Valproate is at least as effective as phenytoin with potentially fewer adverse effects (79% seizure control as second-line agent) 10.

Recent evidence shows phenobarbital has highest seizure control rate (98.1%) but safety concerns exist 8.

Third-Line Options:

Level C Recommendation: Levetiracetam, propofol, or barbiturates may be administered 10.

• Levetiracetam: 20-30 mg/kg IV (efficacy 67-73% in studies) 10
• Propofol: 2 mg/kg bolus, then 5 mg/kg/h infusion 10

Network meta-analysis ranking for second-line agents: Phenobarbital > Levetiracetam > Fosphenytoin > Phenytoin > Valproate 8.

---

Key Clinical Pitfalls

1. Do not use valproate in women of childbearing age unless no alternatives exist 9, 2
2. Do not use carbamazepine in elderly - high drug interactions 4, 2
3. Do not prescribe AEDs after first unprovoked seizure routinely 9
4. Avoid enzyme-inducing AEDs (carbamazepine, phenytoin) in patients with cardiovascular disease or osteoporosis risk 4
5. Levetiracetam should be used cautiously in patients with psychiatric history 4
6. In status epilepticus, administer additional anticonvulsant after benzodiazepine failure - do not delay 10