Xenon

Description

DESCRIPTION Xenon Xe 133 Gas is for diagnostic inhalation use only. It is supplied in vials containing either 370 or 740 megabecquerels (10 or 20 millicuries) of Xenon Xe 133 Gas in 2 milliliters of carrier xenon and atmospheric air. Xenon Xe 133 Gas is chemically and physiologically similar to elemental xenon, a non-radioactive gas which is physiologically inert except for anesthetic properties at high doses. Xenon Xe 133 is produced by fission of Uranium U 235. At the time of calibration, it contains no more than 0.3% Xenon Xe 133m, no more than 1.5% Xenon Xe 131m, no more than 0.06% Krypton Kr 85 and no more than 0.01% Iodine I 131, with no less than 99.9% total radioactivity as radioxenon. Table 1 shows the effect of time on radionuclidic composition. Table 1. Radionuclidic Composition Percent of Total Radioactivity Days % Xe-133 % Xe-133m % Xe-131m % Kr-85 % I-131 -5 >98.3 <0.6 <1.0 <0.03 <0.01 0 Calibration Date >98.1 <0.3 <1.5 <0.06 <0.01 7 >97.2 <0.08 <2.5 <0.15 <0.02 14 Expiration Date >95.7 <0.02 <4.1 <0.37 <0.02

What Is Xenon Used For?

INDICATIONS AND USAGE Xenon Xe 133 Gas has been shown to be valuable for diagnostic inhalation studies for the evaluation of pulmonary function, for imaging the lungs and may also be applied to assessment of cerebral blood flow.

Dosage and Administration

DOSAGE AND ADMINISTRATION Xenon Xe 133 Gas is administered by inhalation from a closed respirator system or spirometer. The final patient dose should be measured by a suitable radioactivity calibration system immediately prior to administration. The recommended activity range employed for inhalation by the average patient (70 kg) is: Pulmonary function including imaging: 74 to 1110 megabecquerels (2 to 30 millicuries) Cerebral blood flow: 370 to 1110 megabecquerels (10 to 30 millicuries) This may be administered as a bolus into the tubing near the patient's mouthpiece or mask after the completion of a tidal exhalation, or by rebreathing for a period of approximately 5 minutes of the Xenon Xe 133 gas in equilibrium with the air contained in the closed system at concentrations of the radionuclide that may vary from 37 to 222 megabecquerels (1.0 to 6.0 millicuries) per liter.

Side Effects (Adverse Reactions)

ADVERSE REACTIONS Adverse reactions specifically attributable to Xenon Xe 133 Gas have not been reported.

Contraindications

CONTRAINDICATIONS None known.

Pregnancy and Breastfeeding

Pregnancy Animal reproduction studies have not been conducted with Xenon Xe 133 Gas. It is also not known whether Xenon Xe 133 Gas can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Xenon Xe 133 Gas should be given to a pregnant woman only if clearly needed. Ideally, all examinations that use radiopharmaceuticals, especially those elective in nature, of a woman of childbearing capability should be performed during the first few (approximately 10) days following the onset of menses.

Nursing Mothers It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Xenon Xe 133 Gas is administered to a nursing woman.

How Supplied

HOW SUPPLIED Xenon Xe 133 Gas is available in 2 milliliter vials with color-coded labels in 370 megabecquerel (10 millicurie; Catalog No. 097) and 740 megabecquerel (20 millicurie; Catalog No. 098) sizes. Both sizes are available in packages of 1, 3 and 5 vials, each with individual lead shielding.