[A case of sustained-release theophylline (Theodur)-induced asthma].

Theophylline is used as a prophylactic agent for controlling bronchospasm in patients with asthma. Sustained-release theophylline (Theodur) is widely used for this purpose. In this report, we describe a patient who developed asthma due to administration of Theodur. A 38-year-old man was referred to our hospital for assessment of the relationship between his respiratory symptoms and theophylline. He had been admitted to the hospital several times for dyspneic attacks. Theophylline ethylenediamine (Aminophylline) and hydrocortisone sodium succinate had been administered intravenously for the acute phase, followed by Theodur orally. Following administration of Theodur, he had developed dyspnea, chest tightness and dizziness. An inhalation challenge test with sulpyline showed a negative reaction. Although an oral challenge test with theophylline also showed a negative reaction, that with Theodur evoked an asthmatic response. We were unable to determined any possible cause or the mechanism for this reaction. We concluded that the vehicle or preservative (i.e., inactive ingredients) contained in Theodur were likely to be related to his asthmatic response.