IV Acetaminophen as an Analgesic Adjunct

A randomized controlled trial to determine the efficacy of 1 gram IV acetaminophen as an
analgesic adjunct to 0.5 mg IV hydromorphone in the treatment of acute severe pain in the
elderly ED patients.

Inclusion Criteria:

- Acute (less than 1 week in duration) severe pain necessitating use of intravenous (IV)
opioids in the judgement of the treating attending physician

Exclusion Criteria:

- Use of other opioids or tramadol within past 24 hours: to avoid introducing assembly
bias related to recent opioid use, since this may affect baseline levels of pain and
need for analgesics.

- Prior adverse reaction to hydromorphone, morphine, or acetaminophen.

- Chronic pain syndrome: frequently recurrent or daily pain for at least 3 months
results in modulation of pain perception which is thought to be due to down-regulation
of pain receptors. Examples of chronic pain syndromes include sickle cell anemia,
osteoarthritis, fibromyalgia, and peripheral neuropathies.

- Alcohol intoxication: the presence of alcohol intoxication as judged by the treating
physician may alter pain perception.

- Systolic Blood Pressure (SBP) <100 mm Hg: Opioids can produce peripheral vasodilation
that may result in orthostatic hypotension.

- Heart Rate (HR) < 60/min: Opioids can cause bradycardia.

- Oxygen saturation < 95% on room air: For this study, oxygen saturation must be 95% or
above on room air in order to be enrolled.

- Use of monoamine oxidase (MAO) inhibitors in past 30 days: MAO inhibitors have been
reported to intensify the effects of at least one opioid drug causing anxiety,
confusion and significant respiratory depression or coma.

- Patients using transdermal pain patches