Answer E is incorrect for the following reasons. There is no guideline regarding the use of imaging methods to assess therapy response. However, individualized assessment with FDG PET appears promising. Osborne et al. analyzed 23 patients with CS who were treated with immunosuppressive therapies and were followed with serial FDG PET imaging. The authors found that a reduction in the volume or intensity of myocardial inflammation was associated with an increase in ejection fraction. 24 Further studies are needed to better understand the role of serial FDG PET imaging in directing therapy.
Fluoroquinolones, including FACTIVE, have been associated with an increased risk of central nervous system (CNS) effects, including convulsions, increased intracranial pressure (including pseudotumor cerebri ), and toxic psychosis . In clinical studies with FACTIVE, central nervous system (CNS) effects have been reported infrequently. As with other fluoroquinolones, FACTIVE should be used with caution in patients with CNS diseases such as epilepsy or patients predisposed to convulsions. CNS stimulation which may lead to tremors, restlessness, anxiety, lightheadedness , confusion, hallucinations, paranoia, depression, insomnia, and rarely suicidal thoughts or acts may also be caused by other fluoroquinolones. If these reactions occur in patients receiving FACTIVE, discontinue FACTIVE immediately and institute appropriate measures.
Another possible modification is to insert a methylene between hydroxyl and lactone on the E-ring yielding a seven membered β-hydroxylactone group, so-called homocamptothecin (hCPT). The hCPT’s hydroxyl has less inductive effect on the carboxyl group which makes the lactone very reactive. This enhances the interaction of the free hydroxyl group optimally with topo I and the covalent complex that forms in its presence are more stable. The E-ring of hCPT opens more slowly and the opening is irreversible . hCPTs exhibit enhanced human plasma stability because of decreased protein binding and more affinity for red blood cells than CPT.