Search

The roles of molecular structure and charge are examined in the transport of cations within montmorillonite clay films. The series of Ru(NH3)63+, Co(NH3)3+, Co(en)33+, Co(sep)3+and Co(bpy)33+are examined in detail via electrochemical and spectrochemical methods. The electrochemical signal is enhanced both in minimizing the time required to develop the signal and in the magnitude of the signal for Ru(NH3)63+. In addition, the potential for the observed reduction peak is shifted negative and the current peak associated with reduction disappears with rinsing of the clay film. These observations are characteristic of a compound that is held by simple electrostatic charge characteristics. In contrast, the compounds Co(NH3)3+, Co(en)33+and Co(sep)3+, while showing rapid and enhanced signal development, eventually evolve a signal that is diminished with respect to the bare electrode, consistent with a hydrophobic mode of retention. The signal for Co(bpy)33+is slow to be observed, is diminished with respect to the bare electrode and is shifted positive in potential, all hallmarks of a strong, non-electrostatic mode of binding within the clay.

OBJECTIVE: To report a severe episode of pruritus and elevated serum transaminases in a patient who was receiving carvedilol.CASE SUMMARY: A 40-year-old white man who had been taking carvedilol for the treatment of cardiomyopathy presented to the emergency department with pruritus over his entire body. Laboratory tests showed elevated serum transaminases. Carvedilol was discontinued and the patient received hydroxyzine hydrochloride to relieve symptoms. Liver function test results returned to normal in three weeks. Approximately one year later the patient was started on metoprolol and within 10 days again developed pruritus. The patient was told to discontinue the metoprolol immediately. At the time the metoprolol was stopped the liver function test results were normal.DISCUSSION: To the best of our knowledge, the adverse reaction presented in this case report is rare. The etiology of this adverse reaction remains unknown but suggests a possible adverse reaction that may recur if the patient is switched to another β-adrenergic blocker. The liver function test abnormalities appear to return to normal on discontinuation of carvedilol.CONCLUSIONS: Carvedilol may cause pruritus and elevated liver function test results. This reaction may recur if the patient is changed to an alternative β-adrenergic blocker. Patients taking carvedilol should be monitored for signs and symptoms of hepatotoxicity. If elevated liver function test results are noted, carvedilol should be discontinued.