Individualization of oral theophylline dosage in elderly patients.

The present study is a prospective evaluation of a dosing nomogram for oral theophylline in 69 middle-aged and elderly patients (mean age 58.5 +/- 15.4 years) with obstructive lung disease. The main features of the nomogram were that the theophylline dose was increased in middle-aged as compared to old patients, and that smokers were always prescribed a higher dose than non-smokers of a similar age. The target theophylline concentration is presently defined as a trough level at steady state of 50 micromol/l. Approximately 50% of the patients achieved theophylline levels within +/- 20% of the target concentration, and none had theophylline levels exceeding 110 micromol/l. We conclude that the nomogram represents a useful guide in establishing a safe initial theophylline dose in this patient group.