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Theophylline does not increase ventilatory responses to hypercapnia or hypoxia
S Swaminathan1, J Y Paton, S L Ward
1Division of Neonatology and Pediatric Pulmonology, Childrens Hospital Los Angeles, University of Southern California School of Medicine 90027.
Oral theophylline, often thought to boost breathing, did not significantly alter respiratory responses to high carbon dioxide or low oxygen levels in healthy adults. Theophylline therapy did not impact chemoreceptor responsiveness despite causing side effects.
Area of Science:
- Respiratory Physiology
- Pharmacology
Background:
- Theophylline is widely believed to stimulate central respiratory centers.
- Its precise impact on ventilatory control requires further investigation.
Purpose of the Study:
- To investigate the effect of oral theophylline on ventilatory responses to hypercapnia and hypoxia.
- To determine if theophylline influences chemoreceptor responsiveness in healthy individuals.
Main Methods:
- A double-blind, placebo-controlled trial was conducted.
- 15 healthy subjects received slow-release oral theophylline or placebo.
- Hypercapnic and hypoxic ventilatory responses were measured using rebreathing techniques.
Main Results:
- Theophylline therapy did not significantly alter hypercapnic or hypoxic ventilatory responses.
- Mean serum theophylline levels were within a therapeutic range.
- 11 out of 15 subjects reported side effects such as nausea and jitteriness.
Conclusions:
- Theophylline, at doses causing side effects, does not affect chemoreceptor responsiveness.
- The common belief of theophylline stimulating central respiratory centers may not be supported by its effect on ventilatory control.
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