Assessing Propylene Glycol Toxicity in Alcohol Withdrawal Patients Receiving Intravenous Benzodiazepines: A One-Compartment Pharmacokinetic Model.

BACKGROUND AND OBJECTIVES: While some case reports indicate that high doses of propylene glycol (PG) may result in metabolic acidosis, there has been no large-scale study that evaluated the risk of metabolic acidosis in patients receiving PG-containing benzodiazepines for acute alcohol withdrawal. This study was undertaken to evaluate the potential toxicity of PG in patients with acute alcohol withdrawal treated with intermittent intravenous bolus doses of diazepam and/or lorazepam. METHODS: This is a retrospective case study using data collected from 18 randomly selected patients receiving one or both of these medications per a modified Clinical Institute Withdrawal Assessment for Alcohol (CIWA) Class 3 protocol. Plasma levels of PG were estimated using a one-compartment pharmacokinetic model. RESULTS: Only two patients had an elevated anion gap compared to their baseline value with one also experiencing a significant increase in serum creatinine. No increases in serum osmolarity were noted. Analysis showed that the benzodiazepine dose received was a good predictor of the estimated PG concentration (r = 0.6), but was poorly correlated with the anion gap. No significant correlation was found with the creatinine clearance or serum creatinine. Patients receiving several daily doses were at higher risk of developing an anion gap (r = 0.33), but the estimated maximum PG concentration did not correlate with the anion gap or serum concentration. CONCLUSION: It does not appear that intermittent bolus administration of intravenous benzodiazepines for alcohol withdrawal influenced renal function or anion gap regardless of number of administered doses, amount of PG received, or the estimated PG concentration.

Residents as preceptors and educators: What we can learn from a national survey to improve our residency programs.

INTRODUCTION: Developing pharmacy residents into effective preceptors is essential to meet the demands of pharmacy education. A survey was created to assess the availability of resident precepting educational opportunities, identify common barriers associated with developing preceptors' skills, and discover strategies to optimize programming. METHODS: An online survey focused on the development of residents as preceptors was e-mailed to all residency program directors (RPD) for American Society of Health-System Pharmacists accredited residencies in the United States. Information was collected on program demographics, level of support and precepting activities offered and resident employment outcomes. RESULTS: Five hundred thirty-eight responses were received. The majority were postgraduate year one RPDs and had less than six residents. Sixty-one percent of programs were affiliated with a college of pharmacy. Seventy-eight percent devoted 10hours or less per month in developing residents as preceptors with 33% providing less than five hours. Seventy-one percent of the residency programs did not offer a formal precepting rotation. However, 59% of respondents indicated that their residency graduates frequently accepted positions, which required teaching/precepting. The most common barriers to developing residents as preceptors included: lack of time for residents to precept within the residency structure (41%), availability of preceptors to mentor residents throughout experience (33%) and lack of preceptors' availability to mentor residents' precepting abilities over time (30%). DISCUSSION AND CONCLUSIONS: RPDs should prioritize training of residents as preceptors. Requiring residents to serve as primary preceptors in rotations dedicated to teaching is important to prepare for future job responsibilities.