Role of theophyllines in severe chronic obstructive pulmonary disease.

Theophyllines are effective bronchodilators, but have other respiratory effects which may be beneficial in patients with chronic obstructive pulmonary disease. These effects include increased diaphragmatic contractility, central respiratory stimulation and anti-inflammatory actions. Some controversy exists however on the precise role of these effects in the clinical setting. We examined the effects of a long-acting theophylline preparation (Uniphyllin Continus) on pulmonary function, and on ventilation and gas exchange during rest, sleep and exercise in a group of 12 patients with severe (FEV1 32 +/- 8.3% predicted), but stable chronic obstructive pulmonary disease. The study was randomised, placebo-controlled, and double-blind in nature. Preliminary analysis of the data indicates a significant improvement in the degree of hyperinflation and gas-trapping with theophylline, and oxygen levels were improved during rest, sleep and exercise while on theophylline. These findings confirm a beneficial effect of theophylline in such patients.