siemens Dimension Phenytoin Flex Reagent Cartridge The PTN method used on the Dimension clinical chemistry system is an in vitro diagnostic test intended to measure phenytoin (dilantin, diphenylhydantoin), an anti-epileptic drug, in human serum and plasma. PTN test results are used in the diagnosis and treatment of phenytoin overdose and in monitoring levels of phenytoin to ensure appropriate therapy.

Internal testing has confirmed a low absorbance range between the levels 1 and 5 calibrators with this lot resulting in the potential for a positive or negative bias and imprecision across the PTN assay range.

Siemens sent an Urgent Medical Device Recall Notification dated September 2014, to all affected customers. The letter identified the product the problem and the action needed to be taken by the customer. Customers were instructed as follows: " Discontinue use and discard any remaining inventory of PTN lot FA5154, and complete the attached form indicating your replacement product needs in the attached Field Correction Effectiveness Form. " Siemens will replace any unused inventory of the affected lot at no charge. We apologize for the inconvenience this situation may have cause. If you have any questions, please contact Siemens Customer Care Center - Technical Solutions at (800) 441-9250, or your local Siemens technical support representative.