A Randomized Study of Intravenous Hydromorphone Versus Intravenous Acetaminophen for Older Adult Patients with Acute Severe Pain.

STUDY OBJECTIVE

We conducted a randomized study to compare the efficacy and adverse event profile of 1,000 mg of intravenous acetaminophen to that of 0.5 mg of intravenous hydromorphone among patients aged 65 years or more with acute pain of severity that was sufficient enough to warrant intravenous opioids.

METHODS

This randomized comparative effectiveness study with 162 participants was conducted in 2 urban emergency departments (EDs). The primary outcome was an improvement in a 0 to 10 pain scale from baseline to 60 minutes later. Secondary outcomes included the need for additional analgesic medication and adverse events that were attributable to the investigational medication. The minimum clinically important difference was an improvement of 1.3 on the 0 to 10 pain scale.

RESULTS

The median baseline pain score was 10 (interquartile range 8 to 10) in both the groups. By 60 minutes, patients taking acetaminophen improved by 3.6 (standard deviation 2.9) on the 0 to 10 pain scale, whereas patients taking hydromorphone improved by 4.6 (standard deviation 3.3) (95% confidence interval [CI] for the difference of 1.0 was 0.1 to 2.0). Additional analgesic medications were required for 37 (46%) of 81 patients taking acetaminophen and 31 (38%) of 81 patients taking hydromorphone (95% CI for the rounded difference of 7% was -8% to 23%). Adverse events were reported by 6 (7%) of 81 patients taking acetaminophen and 10 (12%) of 81 patients taking hydromorphone (95% CI for the difference of 5% was -4% to 14%) and included dizziness, drowsiness, headache, and nausea.

CONCLUSION

Although 0.5 mg of the intravenously administered hydromorphone was statistically superior to 1,000 mg of intravenous acetaminophen administered in older patients with acute severe pain in the ED, this difference was not clinically significant. Regardless of the medication received, many participants experienced minimal or incomplete pain relief.