Unsuspected caffeine toxicity complicating theophylline therapy

Area of Science:

• Pharmacology
• Clinical Medicine
• Toxicology

Background:

• Theophylline is a medication used for respiratory conditions.
• Patients with liver disease may have altered drug metabolism.
• Concurrent use of caffeine can affect theophylline levels.

Observation:

• A patient with alcoholic liver disease and chronic airflow obstruction experienced heart failure and acute bronchitis.
• Elevated plasma caffeine levels were observed despite subtherapeutic theophylline concentrations.
• A caffeine-free diet was implemented.

Findings:

• Theophylline and caffeine challenge tests revealed a high propensity for caffeine accumulation.
• This accumulation occurred even when theophylline levels were below therapeutic range.
• Dietary caffeine significantly impacts methylxanthine levels in patients.

Implications:

• Clinicians must consider dietary caffeine intake in patients receiving theophylline.
• Monitoring methylxanthine levels is essential to prevent toxicity.
• Managing caffeine intake can optimize theophylline therapy and patient safety.