A sensitive and selective electrochemical sensor based on molecularly imprinted polymer for the assay of teriflunomide

In this work, pyrrole-histidine has been designed, synthesized and, used as a novel functional monomer to fabricate a molecularly imprinted electrochemical sensor for the selective and sensitive detection of teriflunomide (TER). The molecularly imprinted thin film of electrochemical sensor was constructed by directly electropolymerization of co-polymer of pyrrole-histidine (PyHis) with pyrrole in the presence of a template, TER, on a glassy carbon electrode (GCE). After electropolymerization, the structure and morphology of the fabricated MIP sensor were characterized by Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) and its electrochemical parameters such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS). The poly (pyrrole-co-pyrrole-histidine) [Poly (Py-co-PyHis)]@MIP/GCE sensor have a linear TER concentration in the of 0.1-1.0 pM with a low detection limit of 11.38 fM. The present strategy for electrochemical sensor have been also showed excellent recovery in synthetic serum samples and tablet dosage form with the recoveries 97.56% and 100.35%, respectively. The developed [Poly (Py-co-PyHis)]@MIP/GCE sensor exhibited an excellent electrochemical response for TER due to the synergistic effect of conducting polymer and molecularly imprinting techniques.

Switching or Discontinuing Disease-Modifying Therapies for Multiple Sclerosis

PURPOSE OF REVIEW

This article reviews the reasons for discontinuation or switching of multiple sclerosis disease-modifying therapy as well as procedures that might mitigate risk to the patient under such circumstances.

RECENT FINDINGS

Recent review of the literature, as well as the author's extensive clinical experience, indicate that the discontinuation of multiple sclerosis disease-modifying therapies occurs for many reasons. Often one medication is stopped at the recommendation of the physician in order to switch to another medication. However, often the decision to discontinue medication is made by the patient. Unfortunately, in still other situations, treatment is stopped because of circumstances beyond the control of either patient or physician (eg, a loss of insurance coverage). Currently available data do not permit a conclusion about whether it is ever safe to discontinue disease-modifying therapy in a stable patient without the expectation of return of disease activity.

SUMMARY

Clinicians must help patients avoid unnecessary and undesirable cessation of disease-modifying therapy. While switches of therapy are often necessary, steps to minimize both adverse events and the risk of recurrent disease should be undertaken. Whether disease-modifying therapy can ever be purposely discontinued without incurring a significant risk of disease recurrence remains to be determined.