Interactions between quibron-t(theophylline) and Cipro cystitis pack (ciprofloxacin)
ciprofloxacin and theophylline (Major Drug-Drug)
GENERALLY AVOID: Coadministration with ciprofloxacin may increase the serum concentrations of theophylline and the associated risk of toxicity. The mechanism is ciprofloxacin inhibition of theophylline metabolism via CYP450 1A2. Case reports and pharmacokinetic studies indicate that ciprofloxacin can reduce the clearance of theophylline by up to 65% in some individuals, resulting in toxic theophylline levels and/or clinical toxicity. Serious reactions and even fatality have been reported during coadministration of theophylline with intravenous ciprofloxacin. These reactions have included cardiac arrest, seizure, status epilepticus, and respiratory failure. Seizures may also occur in the absence of toxic theophylline levels due to additive inhibitory effect of ciprofloxacin and theophylline on gamma-aminobutyric acid (GABA) receptor sites. Because elderly patients and patients with chronic obstructive pulmonary disease, congestive heart failure, or cirrhosis generally have lower theophylline clearance rates, they may be particularly vulnerable to significant interaction with ciprofloxacin. Theophylline does not appear to alter the pharmacokinetics of ciprofloxacin and other quinolones.
MANAGEMENT: The use of theophylline or its salts in combination with ciprofloxacin should generally be avoided. If the combination is prescribed, theophylline dosage may need to be reduced. In patients who are stabilized on theophylline, pharmacologic response and serum levels should be monitored more closely following initiation, discontinuation or change of dosage of ciprofloxacin, and the theophylline dosage adjusted as necessary. Patients should be advised to notify their physician if they experience signs and symptoms suggestive of theophylline toxicity such as nausea, vomiting, diarrhea, headache, tremor, irritability, insomnia, seizures, or palpitations. Other quinolones such as gatifloxacin, gemifloxacin, levofloxacin, lomefloxacin, moxifloxacin, and ofloxacin have been reported to cause minor or no changes in theophylline levels at normally recommended dosages and may be safer alternatives in theophylline-treated patients.
