Comparative effects of ciprofloxacin and lomefloxacin on the oxidative metabolism of theophylline.
Nine healthy male volunteers were studied to assess the interaction between theophylline and ciprofloxacin and to assess whether a similar interaction occurred with lomefloxacin, using a randomised, crossover design. Subjects received theophylline 125 mg 8 hourly with and without lomefloxacin 400 mg 12 hourly or ciprofloxacin 500 mg 12 hourly for 7 days. Ciprofloxacin treatment lowered total theophylline clearance by 27%, owing to a decreased clearance via 1-, 3-demethylation and 8-hydroxylation. Lomefloxacin treatment did not alter theophylline clearance. Ciprofloxacin, at usual clinical doses, could cause a clinically significant interaction when co-administered with theophylline.
Robson
R A
RA
Department of Clinical Pharmacology, Christchurch Hospital, Private Bag, New Zealand.
Begg
E J
EJ
Atkinson
H C
HC
Saunders
D A
DA
Frampton
C M
CM
D000328:Adult; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000494:pharmacology*; D004347:Drug Interactions; D024841:Fluoroquinolones; D006801:Humans; D008297:Male; D010084:Oxidation-Reduction; D015363:Quinolones; D011897:Random Allocation; D013806:Theophylline / Q000378:metabolism*
D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D015363:Quinolones; D002939:Ciprofloxacin; D013806:Theophylline; C053091:lomefloxacin