TECHNESCAN DTPA Kit, Powder for solution for injection Ref.[27726] Active ingredients: Technetium ⁹⁹ᵐTc pentetic acid

Following intravenous injection, technetium (^99mTc) pentetate (DTPA) rapidly distributes throughout the extracellular fluid. Less than 5% of the injected dose is bound to the plasma proteins. There is also a negligible binding of technetium (^99mTc) pentetate (DTPA) to red blood cells. Technetium (^99mTc) pentetate (DTPA) does not cross the normal blood-brain barrier but diffuses weakly in breast milk. Plasma clearance is multi-exponential with an extremely fast component. The complex remains stable in vivo, more than 98% of urine radioactivity is in the form of a chelate. Approximately 90% of the injected dose is eliminated in the urine within the first 24 hours mainly by glomerular filtration. No retention of the compound has been demonstrated in the kidneys. Plasma clearance may be delayed in patients with renal disease. In subjects exhibiting oedema or ascites, distribution of the radionuclide in the extracellular space may be modified.

In lung ventilation studies, after inhalation, technetium (^99mTc) pentetate (DTPA) diffuses rapidly from the pulmonary alveoles towards the vascular space where it is diluted. The half-life of technetium (^99mTc) pentetate (DTPA) in the lungs is slightly less than 1 hour. Many factors are likely to modify the permeability of the pulmonary epithelium like cigarette smoking.

Following oral administration, technetium (^99mTc) pentetate (DTPA) does not pass through the digestive barrier.

This agent is not intended for regular or continuous administration. Repeated intravenous administration of CaNa₃DTPA to rabbits and dogs for 14 days of doses that were 100 and 1000 times (respectively) the normal dose for humans produced no evidence of toxicity. The minimum dose of CaDTPA causing abortion and fetal death in mice was approximately 3600 times the dose of CaNa₃DTPA that is proposed for diagnosis in women. Mutagenicity studies and long-term carcinogenicity studies have not been carried out.