title: Predicting the ciprofloxacin-theophylline interaction from single plasma theophylline measurements.
abstract: The effect of ciprofloxacin treatment on theophylline clearance was evaluated with a theophylline multiple dose, multiple sample protocol and with a single dose, single sample protocol. The object was to determine whether a single dose, single sample protocol for estimating theophylline clearance could be used as a screening strategy for evaluating host factor influences on theophylline clearance. Ciprofloxacin (750 mg per os) was administered every 12 h for nine doses in the multidose study and every 12 h for seven doses in the single dose protocol. Subjects were sixteen healthy, non-smoking young adult males. The oral clearance of theophylline at steady state, (CL/F)ss, decreased from a mean (+/- s.d.) value of 0.035 (+/- 0.008) 1 h-1 kg-1 to 0.024 (+/- 0.004) 1 h-1 kg-1 during ciprofloxacin treatment. Single sample estimates of theophylline clearance, CL/F, similarly decreased from 0.040 (+/- 0.014) 1 h-1 kg-1 to 0.018 (+/- 0.008) 1 h-1 kg-1. Mean theophylline clearances were significantly different when comparing control with ciprofloxacin treatment means (P less than 0.01), but were not different when comparing single sample vs multiple sample clearances for a given treatment (i.e. control or ciprofloxacin). It is concluded that a single dose, single sample strategy may be used in screening for host-factor influences on theophylline clearance.
authors.affiliation: Department of Pharmacology, University of Toledo College of Pharmacy, Ohio 43606.
authors.forename: K A
authors.initials: KA
authors.lastname: Bachmann
authors.forename: J I
authors.initials: JI
authors.lastname: Schwartz
authors.forename: L
authors.initials: L
authors.lastname: Jauregui
mesh_terms: D000284:Administration, Oral; D000328:Adult; D002939:Ciprofloxacin / Q000493:pharmacokinetics*; D004347:Drug Interactions; D006801:Humans; D008297:Male; D013806:Theophylline / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D002939:Ciprofloxacin; D013806:Theophylline