QUINOLONES AND THEOPHYLLINE
Theophylline levels can be markedly increased in some patients by ciprofloxacin, and possibly pefloxacin. Norfloxacin and ofloxacin normally cause a much smaller rise in theophylline levels, although serious toxicity has been seen in a few patients taking norfloxacin. Convulsions have been reported with theophylline and ciprofloxacin or norfloxacin. With some of these cases it is difficult to know whether what happened was due to increased theophylline levels, to patient pre-disposition, to potential additive effects on the seizure threshold, or to all three factors combined.
The dose should be modified based on the theophylline level on day 2 of ciprofloxacin treatment. It may be prudent to follow similar precautions with ofloxacin and norfloxacin. Seizures resulting from concurrent use are relatively rare. Gatifloxacin, levofloxacin, lomefloxacin, moxifloxacin, nalidixic acid and sparfloxacin appear not to significantly affect theophylline levels.
The dose should be modified based on the theophylline level on day 2 of ciprofloxacin treatment. It may be prudent to follow similar precautions with ofloxacin and norfloxacin. Seizures resulting from concurrent use are relatively rare. Gatifloxacin, levofloxacin, lomefloxacin, moxifloxacin, nalidixic acid and sparfloxacin appear not to significantly affect theophylline levels.