Monotherapy with conventional and controlled-release carbamazepine: a double-blind, double-dummy comparison in epileptic patients.
1. Twenty-one epileptic patients completed a double-blind, double-dummy, random order, crossover comparison of conventional carbamazepine (CBZ, Tegretol, Ciba-Geigy) with a new controlled-release formulation (CBZ-CR, Tegretol Retard). All participants were stabilised on maximally tolerated doses of CBZ as monotherapy (one twice daily, twelve three times daily, eight four times daily). Each preparation was taken with a matched placebo of the other for 4 weeks. 2. Peak serum CBZ concentrations (mean +/- s.e. mean) were lower (CBZ 11.4 +/- 0.4 mg l-1; CBZ-CR 10.4 +/- 0.5 mg l-1; P less than 0.01) and times to peak longer (CBZ 3.6 +/- 0.5 h, CBZ-CR 5.2 +/- 0.7 h, P less than 0.01) during CBZ-CR treatment. Mean CBZ concentrations, however, were also slightly reduced with the new formulation (CBZ 9.9 +/- 0.3 mg l-1; CBZ-CR 9.1 +/- 0.5 mg l-1, P less than 0.05) and this was associated with greater seizure frequency (CBZ 2.8 +/- 1.2, CBZ-CR 3.8 +/- 0.9; P less than 0.05) during the CBZ-CR treatment phase. 3. Diurnal fluctuations (CBZ 41 +/- 3%, CBZ-CR 28 +/- 2%, P less than 0.01) and variations (CBZ 53 +/- 5%, CBZ-CR 33 +/- 3%; P less than 0.01) in serum CBZ concentration were substantially less with CBZ-CR and were similar to those calculated during a 6 or 8 hourly dosage interval with conventional CBZ (fluctuation 33 +/- 3%, variation 42 +/- 5%).(ABSTRACT TRUNCATED AT 250 WORDS)
McKee
P J
PJ
University Department of Medicine and Therapeutics, Western Infirmary, Glasgow, Scotland.
Blacklaw
J
J
Butler
E
E
Gillham
R A
RA
Brodie
M J
MJ
D000328:Adult; D002220:Carbamazepine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use*; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004827:Epilepsy / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
D003692:Delayed-Action Preparations; D002220:Carbamazepine; C012227:carbamazepine epoxide