The Concentration of I¹³¹ in the Bronchial Tree after Oral Administration of Tagged CaI₂ and KI

¹ The Departments of Surgery and Otorhinolaryngology, University of Illinois College of Medicine.
² Radioisotope Service, West Side Veterans' Administration, Chicago., The Departments of Surgery and Otorhinolaryngology, University of Illinois College of Medicine.
³ National Institute of Cancer Trainee., The Departments of Surgery and Otorhinolaryngology, University of Illinois College of Medicine.

A group of 12 patients having various bronchopulmonary diseases for which repeated bronchoscopy was indicated were given orally 5 ml. of aqueous solution containing radioactive calcium iodide and two weeks later the same group of patients received 5 ml. of solution containing an equal dose of iodine in the form of radioactive potassium iodide. The concentration of radioactive iodine in bronchial samples, the total urinary drug excretion, and the thyroid uptake were determined following the administration of radioactive iodine in each of the two forms.

In each instance, the excretion in detectable amounts in bronchial aspirates was found at a 15 minute period following administration. The excretion appeared to continue for a period of four hours on the basis of the continued detectability of radio-iodine in aspirates at that time. The highest level of concentration of radioactive iodine was found at an interval of 30 minutes after administration of each drug. Throughout the period of study a higher concentration in bronchial secretion was found after the administration of calcium iodide than after the administration of potassium iodide.

Total urinary drug excretion and thyroid uptake during the first 24 hours following the administration was not different following administration of the two drugs.

These studies suggest that calcium iodide administered orally results in a rate of bronchial secretion greater than that which follows the administration of potassium iodide. Calcium iodide may be a preferable expectorant drug on this basis, even apart from the possible dangers of the administration of potassium salt for the same purpose.