Comparing pain relief methods: IV drip and pill bottle beside a patient post-knee replacement.

Oral vs. IV Acetaminophen: Which Route Eases Pain After Joint Replacement?

Theo Raines in Health & Wellness December 2025 • 4 min read.

"A new study reveals whether intravenous or oral acetaminophen provides better pain relief and reduces narcotic use following hip or knee arthroplasty. Find out which method could be more beneficial for your recovery."

Recovering from hip or knee arthroplasty involves managing pain effectively, and acetaminophen is a common choice. Traditionally, it's been given intravenously (IV) in hospitals, but oral options are available too. Which method works best in the first 24 hours after surgery? Researchers have investigated whether one offers a significant advantage over the other in controlling pain and reducing the need for stronger pain medications.

A study published in "The Journal of Bone & Joint Surgery" compared IV versus oral acetaminophen in patients undergoing hip or knee arthroplasty. The research focused on pain levels and narcotic use within the initial 24-hour recovery period, providing valuable insights for both patients and healthcare providers. The study aimed to determine if the route of administration significantly impacts pain management following joint replacement surgery.

This article breaks down the study's findings, exploring what they mean for your pain management strategy after joint replacement. We'll look at the effectiveness of each method, potential benefits, and what factors might influence the choice between IV and oral acetaminophen.

IV vs. Oral Acetaminophen: What the Research Says About Pain Relief

Comparing pain relief methods: IV drip and pill bottle beside a patient post-knee replacement.

The study, led by Politi JR, Davis RL 2nd, and Matrka AK, was a randomized prospective trial involving 120 patients undergoing hip or knee arthroplasty. Patients were given either IV or oral acetaminophen as part of a standard pain management plan, which included other medications like celecoxib, opioids, and anti-nausea drugs. Pain levels were assessed every four hours using a visual analog scale (VAS), and total narcotic use was also measured.

The researchers found that there was no significant difference in average pain scores between the IV and oral acetaminophen groups over the 24-hour period. Both groups experienced similar levels of pain relief. However, there was a slight difference in the first four hours after surgery.

Overall Pain Scores: No significant difference in average pain scores over 24 hours.
Narcotic Use: No difference in total narcotic use between the two groups.
Early Pain Relief: IV acetaminophen showed slightly better pain control in the first four hours post-surgery.
Standard Regimen: Both groups received a comprehensive pain management protocol.

The key takeaway is that, apart from a slight initial advantage with IV administration, oral and IV acetaminophen provide comparable pain relief and narcotic reduction following hip or knee arthroplasty when used within a standard pain management protocol. This suggests that the choice between the two can be based on other factors, such as patient preference or ease of administration.

Making the Choice: IV or Oral Acetaminophen?

The study suggests that both IV and oral acetaminophen are effective options for managing pain after hip or knee arthroplasty. The slight advantage of IV acetaminophen in the first four hours might be considered for patients needing immediate pain relief. However, oral acetaminophen is a convenient and equally effective alternative for most patients. It's important to discuss with your doctor to determine the best approach based on your individual needs and preferences. Factors like the ability to swallow pills, existing IV lines, and overall comfort can influence the decision. The goal is to create a pain management plan that optimizes your recovery and well-being.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.2106/jbjs.17.00552, Alternate LINK

Title: In Patients Having Hip Or Knee Arthroplasty, Intravenous And Oral Acetaminophen Did Not Differ For 24-Hour Pain Or Narcotic Use

Subject: Orthopedics and Sports Medicine

Journal: Journal of Bone and Joint Surgery

Publisher: Ovid Technologies (Wolters Kluwer Health)

Authors: Shuichi Matsuda

Published: 2017-08-16

Everything You Need To Know

What is acetaminophen, and why is it used after hip or knee arthroplasty?

Acetaminophen is a common pain reliever used after hip or knee arthroplasty. It can be administered either intravenously (IV) or orally. This study compared the effectiveness of both methods in managing pain and reducing narcotic use in the first 24 hours post-surgery. The research highlights how these two routes are commonly used in pain management protocols.

How do IV and oral acetaminophen compare in managing pain after hip or knee arthroplasty?

The study indicates that, overall, there was no significant difference in pain scores between the IV and oral acetaminophen groups over the 24-hour period following hip or knee arthroplasty. Both methods provided similar levels of pain relief and showed no significant difference in the total narcotic use. However, in the initial four hours after surgery, the IV administration provided slightly better pain control. This suggests that both methods are effective for pain management after joint replacement surgery.

Why is this study about IV and oral acetaminophen important?

The significance of this study lies in providing evidence-based insights into pain management strategies after hip or knee arthroplasty. It helps patients and healthcare providers make informed decisions about the best approach for pain relief during recovery. The findings suggest that the choice between IV and oral acetaminophen can be based on factors like patient preference and the ease of administration, as both methods were found to be effective. It could influence standard pain management protocols.

How should someone decide between IV and oral acetaminophen?

The choice between IV and oral acetaminophen should be based on individual needs and circumstances. While IV acetaminophen might offer a slight advantage in the first four hours, oral acetaminophen is a convenient alternative for most patients following hip or knee arthroplasty. Considerations include the ability to swallow pills, the presence of existing IV lines, and overall patient comfort. Healthcare providers will consider all these factors when creating a pain management plan.

What were the key elements of the study's design and methodology?

The study, led by Politi JR, Davis RL 2nd, and Matrka AK, included 120 patients undergoing hip or knee arthroplasty. Patients were given either IV or oral acetaminophen. Both groups received a standard pain management plan, including other medications like celecoxib, opioids, and anti-nausea drugs. Pain levels were measured every four hours using a visual analog scale (VAS), and total narcotic use was assessed. The study design helped to compare the effectiveness of the two methods of administration in a controlled setting.