The Diphenylhydantoin Test System is designed to monitor therapeutic levels of phenytoin (Diphenylhydantoin), a medication commonly used for seizure control. This system typically consists of an analytical device, often employing techniques like chromatography or immunoassays, to provide accurate and rapid results for assessing patient medication levels. The device ensures that patients receive the appropriate dosage and aids healthcare providers in making informed treatment decisions. Regular monitoring is critical, as phenytoin has a narrow therapeutic range, and variations can lead to inefficacy or toxicity.

Intended Use of Diphenylhydantoin Test System

A Diphenylhydantoin Test System is a device intended to measure diphenylhydantoin, an antiepileptic drug, in human specimens. Measurements obtained by this device are used in the diagnosis and treatment of diphenylhydantoin overdose and in monitoring levels of diphenylhydantoin to ensure appropriate therapy.

Intended Use:

Free Phenytoin application is an in vitro test for the quantitative determination of free phenytoin in human serum and plasma on systems. The determination of free phenytoin is used in monitoring levels of free phenytoin to ensure appropriate therapy.

Device Description:

The Phenytoin – Free Phenytoin application is an in vitro test for measuring free phenytoin in human serum and plasma on Cobas c systems. Monitoring these levels is crucial for proper therapy. Samples are processed by ultrafiltration to remove bound phenytoin, enabling accurate measurement of free levels.

This application relies on the kinetic interaction of microparticles in solution (KIMS). Phenytoin antibodies are attached to microparticles, and a drug derivative connects to a macromolecule. A competitive reaction occurs between the drug conjugate and free phenytoin for binding to the antibodies. Turbidity is measured photometrically, where increased turbidity indicates less free phenytoin present in the sample, as turbidity is inversely proportional to its amount.

Levetiracetam Assay

Intended Use:

Levetiracetam II Assay is a homogeneous enzyme immunoassay intended for the quantitative determination of levetiracetam in human serum or plasma on automated clinical chemistry analyzers. Levetiracetam concentrations can be used as an aid in management of patients treated with levetiracetam.

Device Description:

Levetiracetam II Assay is a homogeneous immunoassay that relies on competition between the drug in the specimen and enzyme-labeled levetiracetam for binding to the antibody. When the labeled levetiracetam binds to the antibody, enzyme activity decreases. However, in the presence of the drug from the specimen, enzyme activity increases, which is directly related to the drug’s concentration. The active enzyme converts nicotinamide adenine dinucleotide (NAD) into NADH, and this conversion is measured spectrophotometrically by assessing the rate of change in absorbance. The use of a bacterial enzyme prevents interference from endogenous serum glucose-6-phosphate dehydrogenase (G6PDH), as NAD functions exclusively with the bacterial enzyme utilized in this assay.

Immunoassay, Anti-Seizure Drug

Intended use:

Assay is a homogeneous enzyme immunoassay intended for the quantitative determination of topiramate in human serum or plasma on automated clinical chemistry analyzers.

Device description:

The Lacosamide Assay is a homogeneous enzyme immunoassay that uses a drug and lacosamide labeled with glucose-6-phosphate dehydrogenase (G6PDH) to bind to an antibody reagent. The enzyme activity decreases as the drug binds but increases in the presence of the drug. The active enzyme converts the coenzyme nicotinamide adenine dinucleotide (NAD) to NADH, which is measured spectrophotometrically. Endogenous serum G6PDH does not interfere with the results. The assay consists of two reagents: R1 anti-lacosamide polyclonal antibody and R2 lacosamide labeled with G6PDH enzyme.

Performance Testing (Analytical) for Diphenylhydantoin Test System

• Reagent Stability
• Precision/Reproducibility
• Detection studies- Limit of Blank (LoB), Limit of Detection (LoD), and Limit of Quantitation (LoQ)
• Linearity/assay reportable range
• Traceability (controls, calibrators, or method)
• Analytical specificity (cross reactivity)
• Accuracy(recovery)
• Interfering Substances

Clinical Testing:

No Guidance available for 510k submission