Serum levels, dose and response in prolonged treatment with theophylline
Otero, M.J.; Barrueco, M.; Mariño, E.L.; Gómez, F.; Domínquez-Gil, A.
Medicina Clinica 83(11): 447-449
1984
ISSN/ISBN: 0025-7753 PMID: 6438413 Document Number: 241623
A dosage regimen with theophylline was individualized in 50 asthmatic out-patients by monitoring the serum levels of the drug. Of the patients included in the study, 19 males and 31 females suffering from chronic asthma over a period of 10.13 .+-. 7.85 yr, age range 16-80 yr and a mean weight of 65.86 .+-. 11.21 kg, none were smokers and none showed any overlapping pathology. After the administration of a single dose of 300 mg, the elimination half-life was determined in each patient giving a mean value of 9.06 .+-. 3.46 h. From the individual values of this pharmacokinetic parameter, the initial dose was established for each patient; this gave a mean dose of 9.23 mg/kg per day. After periods of 15 days and 2 mo. the serum levels of theophylline were determined in each patient, correcting the dosage regimen wherever necessary. As well as monitoring the serum levels, studies were also carried out before treatment and after periods of 15 days and 2 mo. on the degree of obstruction of the air passages of each patient to check the validity of the proposed dosage regimen. The CVF parameter showed mean values of 53.96, 64.92 and 72.94%, also at the beginning of treatment, after 15 days and after 2 mo., respectively.