Utilization of serum theophylline concentration determinations

Theophylline, which first saw medical use as a diuretic as early as 1900, became widely used for treatment of bronchospasm associated with asthma and chronic obstruction lung disease in the 1930s. The use of this xanthine derivative as a bronchodilator in reversible airway disease is well established, and its popularity attested to by the large number of commercially available preparations. These include various salts of theophylline, and dosage forms ranging from retention enemas to sustained-release tablets. Currently, this group of products is within the fifty most frequently prescribed drugs in the United States. Various methods exist for dosing theophylline. Perhaps the one most familiar to clinicians is published by Mitenko and Ogilvie. This method advocates a standard loading and maintenance dose for theophylline. Although widely utilized when first published, it has come under criticism more recently as providing unacceptably high concentrations in some patients. Therapeutic efficacy and toxicity of theophylline can be evaluated clinically. However, signs and symptoms such as wheezing or vomiting may not always present. Also, many of the symptoms utilized to assess theophylline dosage require subjective evaluations on the part of the patient and the primary care provider. This type of evaluation is open to great variation. Although it is possible to clinically monitor the patient, this alone may not be sufficient in optimizing patient therapy. Additional data may be required to determine adequacy of therapy. A retrospective descriptive clinical analysis was the study design employed for this chart analysis.