Theophylline - hidden risks

The possibilities of pharmacotherapeutic alleviation of dyspnoea represent an important topic. When choosing medication a great amount of factors need to be considered with respect to medical condition of a particular patient. One of the well-established bronchodilator drug is a purine analogue theophylline. It is important to remember that this caffeine-related substance may in addition to the positive therapeutic effects (bronchodilator, immunomodulatory) show also some characteristic negative ones such as tachycardia, hypokalaemia, diarrhea, insomnia, convulsions, etc. The article describes a case report of a cardiological patient to whom theophylline (600 mg per day) was introduced to improve symptoms of dyspnoea accompanying myocardial infarction. There was a cascade of both acute and chronic side effects that followed (tachycardia, atrial fibrillation, diarrhea, hypokalaemia, behavioral changes). For a long period of time theophylline toxicity was symptomatically treated without discovering the real cause. The case report highlights the importance of making pharmacotherapeutic judgment not only on the empirical basis, but especially on the basis of mastery of the main pharmacological features of the chosen drug and EBM principles.

Keywords: theophylline, arrhythmia, atrial fibrillation, tachycardia, diarrhea, therapeutic drug monitoring.