Avoidance of adverse effects during chronic therapy with theophylline.

Recent definition of the pharmacodynamics and pharmacokinetic characteristics of theophylline and readily available, specific assays have increased the therapeutic benefits from this drug while decreasing the risk of toxicity. Once familiarity is achieved with the various factors that alter clearance, such as age, smoking habits, physiological abnormalities, and concurrent drug therapy, initial dosage can be appropriately individualized. Careful product selection, the slow progressive titration of dose over nine days, and the accurate measurement and interpretation of serum theophylline concentration prevent adverse effects and interactions. However, long-term therapy with theophylline should probably be avoided when other alternatives are available in patients with cor pulmonale, liver dysfunction, cardiac decompensation, migraine headaches, and seizure disorders.