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Published on: October 29, 2020
Ciprofloxacin-induced theophylline toxicity: a population-based study.
Tony Antoniou1, Tara Gomes, Muhammad M Mamdani
1University of Toronto, Toronto, ON, Canada. tantoniou@smh.toronto.on.ca
European Journal of Clinical Pharmacology
|January 15, 2011
Summary
Ciprofloxacin significantly increases the risk of theophylline toxicity in elderly patients. Alternate antibiotics are recommended when possible for those on theophylline therapy to avoid adverse drug events.
Area of Science:
- Pharmacology
- Geriatric Medicine
- Drug Interactions
Background:
- Theophylline is a medication used for respiratory conditions.
- Ciprofloxacin can inhibit the metabolism of theophylline.
- The clinical significance of this drug interaction is not well-established.
Purpose of the Study:
- To investigate the risk of theophylline toxicity associated with co-prescription of ciprofloxacin and theophylline in elderly patients.
- To determine the clinical relevance of the drug interaction between ciprofloxacin and theophylline.
Main Methods:
- Population-based, nested case-control study.
- Cohort of Ontario residents aged 66 years or older treated with theophylline (1992-2009).
- Cases were hospitalized for theophylline toxicity; controls were matched individuals. Odds ratio (OR) calculated for ciprofloxacin use within 14 days prior to hospitalization.
Main Results:
- Nearly twofold increased risk of theophylline toxicity with ciprofloxacin use (adjusted OR 1.86; 95% CI 1.18-2.93).
- No increased risk observed with comparator antibiotics (levofloxacin, trimethoprim-sulfamethoxazole, cefuroxime) (adjusted OR 0.78; 95% CI 0.38-1.62).
- Study included 180 cases and 9000 controls from a cohort of 77,251 theophylline users.
Conclusions:
- Ciprofloxacin treatment is linked to a significant rise in theophylline toxicity risk.
- Clinicians should consider alternative antibiotics for elderly patients on theophylline when appropriate.
- This finding highlights the importance of drug interaction monitoring in geriatric pharmacotherapy.
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