The theophylline content of bronchodilator preparations on the South African market

The availability of over 40 different theophylline-containing preparations on the South African market poses a therapeutic dilemma when a change in bronchodilator becomes necessary, or when a patient on theophylline therapy self-medicates with an over-the-counter theophylline-containing cough medicine. This occurs because of the lack of uniformity in stating the theophylline content on the label. For example, a change in a patient's prescription from Choledyl 200 mg (200 mg oxtriphylline equivalent to 127.2 mg anhydrous theophylline) to Theodur 200 mg (200 mg anhydrous theophylline) will result in an increase in theophylline dose of over 56%. This potential for toxicity is not apparent because the label indicates the mass of the 'salt' rather than the anhydrous theophylline content. A table of currently available theophylline containing preparations on the South African market is presented.