Determination of carbamazepine in fingerprints: a feasibility study to evaluate adherence in epilepsy patients
Isadora Ritter Müller, Valéria Tessaro Grandi, Sarah Gondim Santos Paulino, Bárbara De Villa, Bianca Modena Zembruski, Cassiano Matheus Forcelini, Siomara Regina Hahn, Marina Venzon Antunes, Rafael Linden- Medical Laboratory Technology
- Clinical Biochemistry
- General Pharmacology, Toxicology and Pharmaceutics
- General Medicine
- Analytical Chemistry
Background: Fingerprint drug concentrations can be used as a noninvasive and convenient alternative to evaluate adherence to pharmacotherapy. Methods: Fingerprints were applied over glass slides, extracted and analyzed by ultra-high performance LC–MS/MS. The assay and drug adherence questionnaires were applied to 30 epilepsy patients. Results: The assay had linearity in the range 0.05–10 ng fingerprint-1, with precision of 2.16–7.9% and accuracy of 95.0–102.8%. Carbamazepine (CBZ) levels in fingerprints were stable at 45°C for 15 days. Concentrations in patient samples were 0.06–9.28 ng fingerprint-1. A significant difference (p = 0.003) was found between CBZ concentrations in fingerprints between patient groups divided as low and medium/high adherence. Conclusion: This method can potentially be applied to the identification of epilepsy patients with low adherence to CBZ pharmacotherapy.