title: Efficacy and tolerance of long-term, high-dose gabapentin: additional observations.
abstract: Gabapentin (GBP) has shown antiepileptic efficacy and good tolerance in clinical trials. Much remains to be learned about its clinical use. As a participating center in the US Gabapentin Study Group, we report observations that have practical implications for patient management. Twenty-three patients with intractable partial-onset seizures initiated open-label treatment after a blinded placebo-controlled add-on dose efficacy study. In the titration phase, GBP and concurrent antiepileptic drugs (AEDs) were adjusted to achieve optimal efficacy on maximally tolerated GBP doses. Nine patients had no significant improvement in seizure control and discontinued GBP. The remaining 14 patients were observed while treated long-term with stable-dose GBP and concurrent AEDs. Improvement was maintained as long as patients were followed: < or = 4 years. The protocol-allowed upper dose limit, 2,400 mg/day, was well tolerated by 16 of 23 patients, indicating that higher doses may be tolerated. GBP discontinuation did not cause rebound increases in seizure frequency. The most common adverse events (AEs) (in 14 of 23) were similar to those induced by concurrent AEDs and responded to reduction of concurrent AEDs. Many patients reported positive psychostimulatory effects. These observations extend previous findings indicating that GBP is an effective and well-tolerated drug for treatment of partial-onset seizures.
authors.affiliation: Neurology Service, Department of Veterans Affairs Medical Center, West Los Angeles, California 90073.
authors.forename: A
authors.initials: A
authors.lastname: Handforth
authors.forename: D M
authors.initials: DM
authors.lastname: Treiman
mesh_terms: D000085:Acetates / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000328:Adult; D000588:Amines; D000927:Anticonvulsants / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D003509:Cyclohexanecarboxylic Acids; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D004361:Drug Tolerance; D004828:Epilepsies, Partial / Q000188:drug therapy*; D005260:Female; D005500:Follow-Up Studies; D000077206:Gabapentin; D006801:Humans; D008297:Male; D008875:Middle Aged; D010352:Patient Dropouts; D010919:Placebos; D005680:gamma-Aminobutyric Acid
chemical_list: D000085:Acetates; D000588:Amines; D000927:Anticonvulsants; D003509:Cyclohexanecarboxylic Acids; D010919:Placebos; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin