7/18/2011 1 Clinical Use of Antiepileptic Drugs and Clinical Use of ...

7/18/2011CBZVPATPMLTGLTG &VPATitration rateStart with 200 mg/d,increase 200 mg/d/wkStart with 500 mg/d,increase 500 mg/d/wkStart with 25 mg/d,increase 25-50mgevery 2 weeksStart with 25 -50 mg/dfor 2 weeks,increase by 50–100mg/d every 1–2 wksStart with 25 mg onalternate days 2 wks,then 25 mg/d 2 wks;further increases by 25–50 mg/d every 1–2 wksMinimumdose(mg/d)Maintenance(mg/d)Frequency400–600 400–1600 CR form= bid, tid500–1000* 500–2500 Bid,OD if chrono500 mg/d100 100-400 bid200 200-500 Bid100 100-200 BidOXCLEVGBPPregabalinZNSTitration rateStart with 300 mg/d,Increase 300 mg/d/wkStart with 500 mg/d(or 1000 mg/d),Increase 500 mg/d/wkStart with 300–900 mg/dincrease to target doseover 5–10 daysStart with 50–75 mg/d,increase to 150 mg over2–4 weeks;further increases by75–150 mg every 2 wksStart with 50 mg/d,increases by 50 mg/devery 1–2 weeksMinimumdose(mg/d)Maintenance(mg/d)Frequency600–900 600–2400 bid, tid1000 1000-3000 bid900 900–3600 bid, tid150–300 150–600 bid, tid200 200–600 bid7980Maintenance AED therapyPrinciples of adding a second drug• After reaching un-tolerable level of firstAED• Adjust un-tolerable level of 1 st AED• Sufficient drug titration time• If seizures not under control, switch toanother combinationMaintenance AED therapyPrinciples of adding a second drug• If becoming seizure-free, stay on polytherapyor only add-on AED• If seizures return during or after first AEDwithdrawal, back to previous effectivedose of poly-therapy8182Rational poly-therapy AEDs• Polytherapy• Efficacy: less than additive• Side effects: supra-additive• Two or not more than three AEDs!• Consider• Modes of action• Drug to drug interaction (metabolisminduction, protein binding, etc.)• Adverse effect profilesV83Strategies when treatment fails• About 50% will achieve seizure freedom withoutintolerable side effects on the initially prescribedAED.• If idiosyncratic reaction, avoid, if possible, AEDthat are likely to show cross reactivity.• Carbamazepine has cross reaction of rash with• Phenytoin for 58%,• Phenobarbital for 27%• Oxcarbazepine for 33%• Lamotrigine for 20%.8414