Reduction in the oral doses of theophylline in asthmatic children during concomitant treatment with ketotifen.
Sixteen children with moderate or severe bronchial asthma underwent a double-blind study receiving either ketotifen (K) or placebo (P) in order to verify the sparing effect of K on theophylline. The study lasted 18 weeks. Slow release theophylline was administered to all patients at a dose of 300 mg every 12 hours for the first six weeks of the study ("washout"). From the seventh week on, eight patients received K (1 mg, 2x/day) and the others P. The theophylline dose was maintained and reduced every 4 weeks to 200 mg and 100 mg. The initial clinical characteristics were identical in both groups. The serum levels of theophylline decreased below the ideal range (less than 10 mcg/ml) in groups K and P with a 100 mg dose of theophylline. However, in group K patients, fewer reported worsening of symptoms (number of days with cough and/or wheeze, altered daytime or nighttime peak expiratory flow rate and consumption of beta agonist) when compared to group P. Increased PC20 of methacholine only occurred in group K patients.
Solé
D
D
Dept. of Pediatrics, Escola Paulista de Medicina, São Paulo, Brazil.
Mallozi
M C
MC
Toledo
E C
EC
Passos Soares
F J
FJ
Naspitz
C K
CK
D000284:Administration, Oral; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000188:drug therapy*; D002648:Child; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D006801:Humans; D007665:Ketotifen / Q000008:administration & dosage* / Q000627:therapeutic use; D016210:Methacholine Chloride; D012123:Pulmonary Ventilation; D013806:Theophylline / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000627:therapeutic use; D014797:Vital Capacity
D003692:Delayed-Action Preparations; D016210:Methacholine Chloride; D013806:Theophylline; D007665:Ketotifen