Single dose and steady-state pharmacokinetics of 4 mg and 8 mg oral salbutamol controlled-release in patients with bronchial asthma.
Fifteen patients with asthma were given salbutamol controlled-release (SCR) 4 mg or 8 mg twice daily for seven days, in a randomised double-blind cross-over design. Plasma salbutamol levels were measured after the first and fifteenth doses for a 12 h period following drug ingestion. At steady-state the geometric mean values for Cmax were 8.2 ng/ml for 4 mg, and 16.1 ng/ml for 8 mg. Median tmax values were 300 and 240 min respectively. The geometric mean AUC (0-12) were 4507 ng.min.ml-1 and 8980 ng.min/ml. Peak to trough fluctuation ratios were 0.577 and 0.572. There were no significant differences between 4 mg or 8 mg formulations, for any of the parameters measured, after appropriate corrections for dose. The concentration-time profiles at steady-state showed little fluctuation in plasma salbutamol levels over the twelve hour dosing interval. These results show that 4 mg and 8 mg formulations of SCR provide smooth plasma profiles at steady-state with a twice daily dosing regime.
Lipworth
B J
BJ
Department of Clinical Pharmacology, Ninewells Hospital and Medical School, Dundee, UK.
Clark
R A
RA
Dhillon
D P
DP
Charter
M K
MK
Palmer
J B
JB
McDevitt
D G
DG
D000328:Adult; D000420:Albuterol / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic; D013997:Time Factors
D003692:Delayed-Action Preparations; D000420:Albuterol