Acetaminophen injection: a review of clinical information including forms not available in the United States

Kidney Injury Following Ibuprofen and Acetaminophen: A Real-World Analysis of Post-Marketing Surveillance Data

Background: Although kidney injury has been reported as a serious adverse effect in patients treated with ibuprofen or acetaminophen (APAP), there are still few real-world studies to compare the specific differences in the adverse effects of nephrotoxicity.

Methods: Disproportionality analysis and Bayesian analysis were devoted to data-mining of the suspected kidney injury after using ibuprofen and APAP based on the FDA’s Adverse Event Reporting System (FAERS) from January 2004 to March 2021. The times to onset, fatality, and hospitalization rates of ibuprofen-associated kidney injury and APAP-associated kidney injury were also investigated.

Results: 2,453 reports of ibuprofen-associated kidney injury and 1,288 reports of APAP-associated kidney injury were identified. Ibuprofen appeared to affected more middle-aged patients than elderly ones (27.76 vs 16.53%) while APAP appeared to affected more young patients than middle-aged patients (45.24 vs 29.10%) and elderly patients were fewer (13.99%). Compared to ibuprofen, APAP had the higher association with renal injury based on the higher reporting odds ratio (ROR = 2.45, 95% two-sided CI = 2.36–2.56), proportional reporting ratio (PRR = 2.39, χ² = 2002.94) and empirical Bayes geometric mean (EBGM = 2.38, 95% one-sided CI = 2.3). In addition, APAP-associated kidney injury had earlier onset (32.74 vs 115.82 days, p < 0.0001) and a higher fatality rate (44.43 vs 7.36%, p < 0.001) than those of ibuprofen-associated kidney injury.

Conclusion: The analysis of FAERS data provides a more accurate profile on the incidence and prognosis of kidney injury after ibuprofen and acetaminophen treatment, enabling continued surveillance and timely intervention in patients at risk of kidney injury using these drugs.

Randomized Trial of Adding Parenteral Acetaminophen to Prochlorperazine and Diphenhydramine to Treat Headache in the Emergency Department

Introduction

Headaches represent over three million emergency department (ED) visits per year, comprising 2.4% of all ED visits. There are many proposed methods and clinical guidelines of treating acute headache presentations. However, data on intravenous acetaminophen usage in these settings are lacking. In this study, we sought to determine the efficacy of intravenous (IV) acetaminophen as an adjunct to a standard therapy for the treatment of patients who present to the ED with a chief complaint of “headache.”

Methods

We conducted a single site, randomized, double-blind, placebo-controlled trial investigating the clinical efficacy of IV acetaminophen as an adjunct to a standard therapy with prochlorperazine and diphenhydramine for the treatment of patients who present to the ED with a chief complaint of “headache” or variants thereof. (See below for variants). The primary outcome measure of the efficacy of parenteral acetaminophen as an adjunct treatment for headache in addition to a standard therapy was a threshold two-point reduction in visual analog scale (VAS) pain scores on a 1–10 level at 90 minutes. Secondary outcomes measures included assessment of decreased requirement of “rescue” pain medicines, defined as any analgesic medications outside of diphenhydramine, prochlorperazine and acetaminophen, with particular interest to potential opioid-sparing effects with parenteral acetaminophen. Additional secondary outcome measure included time to disposition from arrival in the ED.

Results

For the acetaminophen group the initial mean pain score was 8.67, for the placebo group 8.61. At 90 minutes pain score was 2.23 for the acetaminophen group and 3.99 for placebo (p<0.01, 95% confidence interval (CI) [0.8%–16%]. Of 45 patients in each group, we observed at least a threshold two-point decrease in pain score 36/45 (80%) with acetaminophen vs. 25/45 (55%) with placebo (p <0.01) 95% CI [5%–41%], number needed to treat (NNT) = 4). Secondary outcome measure did not demonstrate a difference in length of stay (161 minutes for acetaminophen arm and 159 minutes for placebo). However, 17/45 (38%) of patients who received IV acetaminophen required rescue analgesia, opposed to 24/45 (53%) of patients in the placebo group (p=0.13) 95% CI [−5%–34%].

Conclusion

IV acetaminophen when used with prochlorperazine and diphenhydramine to treat acute headaches in the ED resulted in statistically significant pain reduction compared with prochlorperazine and diphenhydramine alone as measured by both threshold of lowering VAS pain score by at least two points (NNT = 4) and overall decline in VAS pain score. Further study is required to validate these results.