Oral theophylline for chronic obstructive pulmonary disease

Area of Science:

• Pulmonary Medicine
• Pharmacology
• Respiratory Diseases

Background:

• Oral theophylline has been a long-standing bronchodilator for Chronic Obstructive Pulmonary Disease (COPD).
• Despite newer agents, theophylline remains recommended for COPD management due to its therapeutic role.
• Its narrow therapeutic index necessitates careful consideration in treatment protocols.

Purpose of the Study:

• To evaluate the efficacy of oral theophylline compared to placebo in stable COPD patients.
• To synthesize evidence from randomized controlled trials (RCTs) on theophylline's effectiveness.

Main Methods:

• Systematic search of Cochrane Airways Review Group and Cochrane Controlled Clinical Registers.
• Inclusion of all relevant randomized controlled trials (RCTs).
• Independent data abstraction and quality assessment by two reviewers.

Main Results:

• Twenty RCTs were included, with varied concomitant therapies.
• Significant improvements observed in FEV1 (WMD 100 ml) and FVC (WMD 210 ml) compared to placebo.
• Modest improvements in VO2max and arterial blood gas tensions (PaO2, PaCO2) were noted.
• No significant improvement in walking distance or breathlessness scores; increased risk of nausea.
• Higher patient preference for theophylline over placebo, with very low dropout rates.

Conclusions:

• Theophylline provides modest improvements in FEV1, FVC, and arterial blood gases for moderate to severe COPD.
• Benefits were observed across various concomitant therapies.
• Exercise performance improvements were inconsistent, depending on testing methodology.
• Low dropout rates suggest potential investigator bias towards theophylline-tolerant patients, limiting generalizability.