Evaluation of a Food and Drug Administration Mandate to Limit Acetaminophen in Prescription Combination Products

A Retrospective Review of Hospitalized Patients Receiving a Higher than Maximum Dose of Acetaminophen

BACKGROUND

Although the 3 to 4 gram per 24 hours dose recommended for daily use are generally safe, case reports and some series raise concerns about nonacute excessive doses in some individuals.

OBJECTIVE

To assess the safety of dosing more than 4 grams of acetaminophen in a 24-hour period in hospitalized patients and develop a method to evaluate the ongoing practice of acetaminophen dosing. Methods: We performed a retrospective chart review of supratherapeutic doses of acetaminophen over a 2-year period. Outcomes included death and the need for liver transplant. A "best practices alert" (BPA) was then developed in our EMR when more than 4 grams of acetaminophen was either prescribed or administered in a 24- hour period. Twelve months of alerts were then retrospectively reviewed and evaluated.

RESULTS

152 cases of dosing more than 4 grams were initially identified. No cases of death related to liver failure or liver transplant were found in any of these patients. 482 cases were identified after a BPA was put in place where the alert was overridden. There were no deaths and no cases that required liver transplantation due to liver failure. The majority of overrides were due to the allowed window of timing for nursing administration of acetaminophen for scheduled doses and overlap with as needed dosing.

CONCLUSION

Supratherapeutic dosing of acetaminophen in our patients did not lead to death or liver transplant. A BPA in our EMR has allowed better evaluation of patterns of acetaminophen use at our university health system.

Paracetamol (acetaminophen) overdose and hepatotoxicity: mechanism, treatment, prevention measures, and estimates of burden of disease

INTRODUCTION

Paracetamol is one of the most used medicines worldwide and is the most common important poisoning in high-income countries. In overdose, paracetamol causes dose-dependent hepatotoxicity. Acetylcysteine is an effective antidote, however despite its use hepatotoxicity and many deaths still occur.

AREAS COVERED

This review summarizes paracetamol overdose and toxicity (including mechanisms, risk factors, risk assessment, and treatment). In addition, we summarize the epidemiology of paracetamol overdose worldwide. A literature search on PubMed for poisoning epidemiology and mortality from 1 January 2017 to 26 October 2022 was performed to estimate rates of paracetamol overdose, liver injury, and deaths worldwide.

EXPERT OPINION

Paracetamol is widely available and yet is substantially more toxic than other analgesics available without prescription. Where data were available, we estimate that paracetamol is involved in 6% of poisonings, 56% of severe acute liver injury and acute liver failure, and 7% of drug-induced liver injury. These estimates are limited by lack of available data from many countries, particularly in Asia, South America, and Africa. Harm reduction from paracetamol is possible through better identification of high-risk overdoses, and better treatment regimens. Large overdoses and those involving modified-release paracetamol are high-risk and can be targeted through legislative change.

Decision tree outcome prediction of acute acetaminophen exposure in the United States: A study of 30,000 cases from the National Poison Data System

Acetaminophen is one of the most commonly used analgesic drugs in the United States. However, the outcomes of acute acetaminophen overdose might be very serious in some cases. Therefore, prediction of the outcomes of acute acetaminophen exposure is crucial. This study is a 6-year retrospective cohort study using National Poison Data System (NPDS) data. A decision tree algorithm was used to determine the risk predictors of acetaminophen exposure. The decision tree model had an accuracy of 0.839, an accuracy of 0.836, a recall of 0.72, a specificity of 0.86 and an F1_score of 0.76 for the test group and an accuracy of 0.848, a recall of 0.85, a recall of 0.74, a specificity of 0.87 and an F1_score of 0.78 for the training group. Our results showed that elevated serum levels of liver enzymes, other liver function test abnormality, anorexia, acidosis, electrolyte abnormality, increased bilirubin, coagulopathy, abdominal pain, coma, increased anion gap, tachycardia and hypotension were the most important factors in determining the outcome of acute acetaminophen exposure. Therefore, the decision tree model is a reliable approach in determining the prognosis of acetaminophen exposure cases and can be used in an emergency room or during hospitalization.

Paracetamol poisoning: a population-based study from Iceland

OBJECTIVE

To examine the incidence and severity of paracetamol poisoning in a population-based cohort in Iceland. A previous study showed a decrease in the incidence during a financial crisis in Iceland, by approximately half (16/100,000 annually). The aims of the study were to assess the incidence and nature of paracetamol poisoning after economic recovery in Iceland and to compare intentional and accidental poisoning.

METHODS

Paracetamol serum concentrations were used to identify patients in this retrospective study from 2010-2017. A search was undertaken in laboratory databases for patients with serum paracetamol concentrations, which were grouped by <66 µmol/L (below detection limit) and ≥66 µmol/L. Medical records were reviewed and relevant laboratory and clinical information obtained to determine whether paracetamol poisoning had occurred.

RESULTS

Altogether 542 cases of paracetamol poisoning were identified. The mean annual incidence was 27/100,000 (range 22-33). Intentional poisoning was observed in 437/542 (81%) cases, most frequently among females 16-25 years of age. Males ≥65 years were more likely to overdose by accident, which was associated with worse outcomes. Twenty-five (4.6%) patients developed severe paracetamol-induced liver injury and coagulopathy. Overall, six (1.1%) cases were fatal in which paracetamol contributed to the cause of death, with accidental poisoning found in 67% (4/6).

CONCLUSIONS

The incidence of paracetamol poisoning has increased in recent years associated with economic recovery in Iceland. Most patients had favourable outcomes. Intentional overdose was most common in young females, whereas accidental overdose was more common in older males and more frequently associated with a fatal outcome.

Effects of hydrocodone rescheduling on opioid use outcomes: A systematic review

OBJECTIVE

To evaluate opioid prescribing, dispensing, and use in relation to hydrocodone-containing product (HCP) rescheduling.

METHODS

Seven biomedical databases and grey literature sources were searched with keywords and database-specific controlled vocabulary relevant to HCP rescheduling for items published between January 2014 and July 2019. We included English-language quasi-experimental studies that assessed changes in HCP and other opioid prescribing, dispensing, utilization, and opioid-related health outcomes before and after HCP rescheduling. A data extraction sheet was created for this review. Two authors evaluated risk of bias for each included study. Two of 4 authors each independently extracted patient demographics and opioid-related outcomes from the included studies. Conflicts were resolved by a third author.

RESULTS

All studies identified (n = 44) were quasi-experimental in design with 10 using an interrupted time series approach. A total of 24 studies reported a decrease in HCP prescribing by 3.1%-66.0%. Six studies reported a decrease in HCP days' supply or doses by 14.0%-80.8%. There was increased prescribing of oxycodone-containing products by 4.5%-13.9% in 5 studies, tramadol by 2.7%-53.0% in 9 studies, codeine-containing products by 0.8%-1352.9% in 8 studies). Five studies reported a decrease in morphine equivalents by at least 10%, whereas 2 studies reported an increase in morphine equivalents. Differences in populations, sample sizes, and approaches did not allow for a meta-analysis. Details regarding approach and findings were limited in published conference abstracts (n = 16).

CONCLUSIONS

Hydrocodone rescheduling was associated with reductions in prescribing and use of HCPs but was also associated with increased prescribing and use of other opioids, both schedule II and nonschedule II.

Predicting Opioid Use Following Discharge After Cesarean Delivery

PURPOSE

Although cesarean delivery is the most common surgical procedure in the United States, postoperative opioid prescribing varies greatly. We hypothesized that patient characteristics, procedural characteristics, or both would be associated with high vs low opioid use after discharge. This information could help individualize prescriptions.

METHODS

In this prospective cohort study, we quantified opioid use for 4 weeks following hospital discharge after cesarean delivery. Predischarge characteristics were obtained from health records, and patients self-reported total opioid use postdischarge on weekly questionnaires. Opioid use was quantified in milligram morphine equivalents (MMEs). Binomial and Poisson regression analyses were performed to assess predictors of opioid use after discharge.

RESULTS

Of the 233 patients starting the study, 203 (87.1%) completed at least 1 questionnaire and were included in analyses (86.3% completed all 4 questionnaires). A total of 113 patients were high users (>75 MMEs) and 90 patients were low users (≤75 MMEs) of opioids postdischarge. The group reporting low opioid use received on average 44% fewer opioids in the 24 hours before discharge compared with the group reporting high opioid use (mean = 33.0 vs 59.3 MMEs, P <.001). Only a minority of patients (11.4% to 15.8%) stored leftover opioids in a locked location, and just 31 patients disposed of leftover opioids.

CONCLUSIONS

Knowledge of predischarge opioid use can be useful as a tool to inform individualized opioid prescriptions, help optimize nonopioid analgesia, and reduce opioid use. Additional studies are needed to evaluate the impact of implementing such measures on prescribing practices, pain, and functional outcomes.