2'-C-Methyl branched pyrimidine ribonucleoside analogues: potent inhibitors of RNA virus replication.

RNA viruses are the agents of numerous widespread and often severe diseases. Their unique RNA-dependent RNA polymerase (RDRP) is essential for replication and, thus, constitutes a valid target for the development of selective chemotherapeutic agents. In this regard, we have investigated sugar-modified ribonucleoside analogues as potential inhibitors of the RDRP. Title compounds retain 'natural' pyrimidine bases, but possess a beta-methyl substituent at the 2'-position of the D- or L-ribose moiety. Evaluation against a broad range of RNA viruses, either single-stranded positive (ssRNA+), single-stranded negative (ssRNA-) or double-stranded (dsRNA), revealed potent activities for D-2'-C-methyl-cytidine and -uridine against ssRNA+, and dsRNA viruses. None of the L-enantiomers were active. Moreover, the 5'-triphosphates of the active D-enantiomers were found to inhibit the bovine virus diarrhoea virus polymerase. Thus, the 2'-methyl branching of natural pyrimidine ribonucleosides transforms physiological molecules into potent, broad-spectrum antiviral agents that merit further development.

Synthesis and pharmacokinetics of valopicitabine (NM283), an efficient prodrug of the potent anti-HCV agent 2'-C-methylcytidine.

In our search for new therapeutic agents against chronic hepatitis C, a ribonucleoside analogue, 2'-C-methylcytidine, was discovered to be a potent and selective inhibitor in cell culture of a number of RNA viruses, including the pestivirus bovine viral diarrhea virus, a surrogate model for hepatitis C virus (HCV), and three flaviviruses, namely, yellow fever virus, West Nile virus, and dengue-2 virus. However, pharmacokinetic studies revealed that 2'-C-methylcytidine suffers from a low oral bioavailability. To overcome this limitation, we have synthesized the 3'-O-l-valinyl ester derivative (dihydrochloride form, valopicitabine, NM283) of 2'-C-methylcytidine. We detail herein for the first time the chemical synthesis and physicochemical characteristics of this anti-HCV prodrug candidate, as well as a comparative study of its pharmacokinetic parameters with those of its parent nucleoside analogue, 2'-C-methylcytidine.

Incorporation of hands-on sterile technique instruction in an introductory pharmacy practice experience.

OBJECTIVE: To examine sterile technique and basic sterile compounding procedures among third-year pharmacy students. DESIGN: Third year pharmacy students participating in an introductory pharmacy practice experience (IPPE) in 2012 (n=126) and 2013 (n=119) performed a modified low-risk compounded sterile product (CSP) media fill challenge test, then prepared a 5 mg/mL vancomycin solution that was subsequently analyzed for accuracy. ASSESSMENT: To identify deficiencies in sterile procedures, students were observed while performing a modified low-risk CSP media fill challenge test. In the first year of conducting the challenge test (2012), 3 deficiencies were identified: hand washing before compounding, cleaning items with alcohol prior to start, and cleaning work area upon completion. In 2013, significant improvements were observed in these 3 areas after students watched a demonstration video. Examination of CSPs revealed less than 1% contamination in both years. Analysis of compounded vancomycin solutions showed that 84% and 71% of students prepared solutions in 2012 and 2013, respectively, were within 10% of the targeted final concentration. CONCLUSION: Hands-on sterile compounding exercises are typically delivered early in the pharmacy professional curriculum with minimal reinforcement in subsequent years. Providing opportunities for advanced pharmacy students to refresh and practice sterile compounding procedures allows students to refine their skills before entering pharmacy practice.

Pediatric psychopharmacology and local anesthesia: potential adverse drug reactions with vasoconstrictor use in dental practice.

Pain management is important when dealing with pediatric dental patients. The use of local anesthetics can be especially challenging for children taking psychotropic medications. The purpose of this paper was to identify pertinent information regarding drug interactions between vasoconstrictor/local anesthetic combinations and medications for the management of psychiatric or behavior disorders in children. Many of the reported interactions are controversial, largely theoretical with very limited clinical evidence, and not well defined. However, when considering the potential for significant increased blood pressure when local anesthesia containing a vasoconstrictor is used, a thorough under standing of the pharmacological actions of medications used to treat psychiatric or behavioral disorders and vasoconstrictors can help dental professionals minimize the potential risk of drug interactions in their practice.

Pharmacist attire and its impact on patient preference.

OBJECTIVE: To determine the influence of demographics on patient preferences for community pharmacist attire. METHODS: A 10-item questionnaire was developed and administered to patients visiting a chain pharmacy or an independent pharmacy in the Birmingham, Alabama metropolitan area. Mann-Whitney was used to examine if statistical differences existed in chain versus independent pharmacy patient's selections based on pharmacist attire. RESULTS: A statistically significant difference in patient preference for pharmacist attire between the settings in regards to which pharmacist patients felt was more approachable was observed; 51.2% of chain pharmacy respondents compared to 30% of independent pharmacy respondents identified the pharmacist pair with business formal attire and white coat as more approachable. Differences in education was also apparent with 70% of respondents in the independent pharmacy setting reporting having a Bachelor's degree or higher compared to 45% of respondents in the chain pharmacy setting. CONCLUSIONS: With the exception of approachability, patients indicated preference for pharmacist with the white coat regardless of community setting. Given the importance of patient-pharmacist communication for building successful patient-pharmacist relationships, if patients do not perceive the pharmacists as approachable, communication and subsequent development of said relationships may not occur regardless of perceived knowledge and competency.

Evaluation of the role of three candidate human kinases in the conversion of the hepatitis C virus inhibitor 2'-C-methyl-cytidine to its 5'-monophosphate metabolite.

Nucleoside analogs are effective inhibitors of the hepatitis C virus (HCV) in the clinical setting. One such molecule, 2'-C-methyl-cytidine (2'-MeC), entered clinical development as NM283, a valine ester prodrug form of 2'-MeC possessing improved oral bioavailability. To be active against HCV, 2'-MeC must be converted to 2'-MeC triphosphate which inhibits NS5B, the HCV RNA-dependent RNA polymerase. Conversion of 2'-MeC to 2'-MeC monophosphate is the first step in 2'-MeC triphosphate production and is thought to be the rate-limiting step. Here we investigate which of three possible enzymes, deoxycytidine kinase (dCK), uridine-cytidine kinase 1 (UCK1), or uridine-cytidine kinase 2 (UCK2), mediate this first phosphorylation step. Purified recombinant enzymes UCK2 and dCK, but not UCK1, could phosphorylate 2'-MeC in vitro. However, siRNA knockdown experiments in three human cell lines (HeLa, Huh7 and HepG2) defined UCK2 and not dCK as the key kinase for the formation of 2'-MeC monophosphate in cultured human cells. These results underscore the importance of confirming enzymatic kinase data with appropriate cell-based assays. Finally, we present data suggesting that inefficient phosphorylation by UCK2 likely limits the antiviral activity of 2'-MeC against HCV. This paves the way for the use of a nucleotide prodrug approach to overcome this limitation.