Knee replacement surgery can reduce pain and increase mobility in the long term, but pain will be present after the procedure and during recovery. You should feel fully comfortable again after 6-12 months. Meanwhile, medication can help manage the pain.

During a total knee replacement, a surgeon will remove damaged tissue and implant an artificial knee joint.

On average, a knee replacement lasts 15-20 years. That said, speak with your doctor to determine if the benefits outweigh the pain after the procedure and the time it may take to recover.

There are a few categories of medications you will encounter during and after knee replacement. During the procedure, most people need to be put under general anesthesia, though it may, in some cases, be local anesthesia.

After the procedure, most people need medications to:

  • minimize pain
  • manage nausea and constipation
  • prevent blood clots
  • lower the risks of an infection

With appropriate treatment and physical therapy, many people recover from a knee replacement and are able to return to their everyday activities within weeks.

Without adequate pain management, you may have difficulty starting rehabilitation and moving around after surgery.

Rehabilitation and mobility are important because they improve the chances of a positive outcome.

Your surgeon may choose from various options, and it may even be a combination of the following:

  • Nonsteroidal anti-inflammatories (NSAIDs) or acetaminophen (Tylenol): These can be over-the-counter medications or prescription strength if you need them.
  • Opioids: These include morphine (MS-Contin, Avinza, and others), oxycodone (Oxaydo, Roxicodone), or hydrocodone (Hysingla).
  • Peripheral nerve blocks: These are administered by inserting an intravenous (IV) catheter into areas of the body near nerves that transmit pain messages to the brain.
  • Patient-controlled (PCA) pumps: These contain opioid pain medication and allow you to control the dose by pressing a button. The machine is programmed to release a certain amount over time, which helps prevent overdose.
  • Liposomal bupivacaine (Exparel): This is a newer medication for pain relief that a doctor injects into the surgical site. It releases a continuous analgesic to relieve pain for up to 72 hours after your procedure. Your doctor may prescribe this drug along with other pain medications.
  • Gabapentin (Neurontin) or pregabalin (Lyrica): These are medications that specifically treat certain seizures and nerve pain. However, doctors may prescribe them before your surgery to reduce pain after the procedure.

Find out more about pain medication for a total knee replacement.

After knee replacement surgery, there is a risk of developing a blood clot. A clot in the deeper blood vessels is called deep vein thrombosis (DVT). They usually occur in the leg.

However, a clot can sometimes break off and travel around the body. If it reaches the lungs, it can result in pulmonary embolism. If it reaches the brain, it can lead to a stroke. These are life threatening emergencies.

There is a higher risk of DVT after surgery because:

  • Your bones and soft tissue release proteins that aid in clotting during surgery.
  • Being immobile during surgery can reduce blood circulation, increasing the chance that a clot will develop.
  • You won’t be able to move around very much for a while after surgery, which can also lead to blood pooling in one area and, therefore, may lead to a clot.

Your doctor will prescribe medication to reduce the risk of blood clots after surgery. These could include:

  • Aspirin: This is an over-the-counter pain reliever that also thins your blood
  • low-molecular-weight heparin: You can receive this by injection or through a continuous IV infusion
  • Other injectable anticlotting medications: These include such as fondaparinux (Arixtra) or enoxaparin (Lovenox)
  • Other oral medications: These include warfarin (Coumadin), apixaban (Eliquis), and rivaroxaban (Xarelto)

The options and tour dose will depend on your medical history, including any allergies and whether you have a risk of bleeding.

Infection is another serious complication that can arise during knee replacement surgery.

In the past, around 1 in 20 people developed an infection, but the current rate is around 1.1%. This is because surgeons now give antibiotics before surgery, and they may continue to give them for 24 hours after.

People with diabetes, obesity, circulatory problems, and conditions that affect the immune system, such as HIV, have a higher chance of getting an infection.

If an infection develops, the doctor will prescribe another course of antibiotics.

If this happens, it is essential to take the whole course of treatment, even if you feel better. If you stop a course of antibiotics partway through, the infection may return and may be more difficult to treat if it becomes resistant to the antibiotic.

In addition to medications to reduce pain and risks of blood clots after knee replacement, your doctor may prescribe other therapies to minimize the side effects of anesthesia and pain medicines.

Despite if you take preventive drugs, the chance of you getting nausea and vomiting after general anesthesia is around 30%. In another study of 20 surgeries, 74% of people reported getting constipated after the procedure.

Anti-nausea medications include:

  • ondansetron (Zofran)
  • promethazine (Phenergan)

Medications for constipation or stool softeners include:

  • docusate sodium (Colace)
  • bisacodyl (Dulcolax)
  • polyethylene glycol (MiraLAX)

When it comes to treating or managing pain after knee replacement, your doctor may recommend additional natural approaches such as massage, acupuncture, or practices like yoga. These usually don’t replace medications but can complement them as part of your treatment.

Some research suggests that a high dose of vitamin C may help reduce inflammation and improve recovery, especially if injected intravenously immediately after surgery.

Other possible natural pain relievers include alpha lipoic acid and L-carnitine transferase. That said, more research is needed to understand the effect of these on pain, specifically after knee replacement, and they’re currently not part of the accepted treatment guidelines.

There are also some dietary changes you can make and other vitamins you might consider taking as you recover.

Learn more: Vitamins and supplements for joint health and knee replacement success and how to manage pain, swelling, and bruising after a total knee replacement.

What is the best painkiller after knee replacement?

There isn’t a single best pain medication to take after knee replacement, as every person may respond differently to different drugs. Your doctor will prescribe what they believe would work best for you while minimizing side effects based on your specific case.

That said, depending on the degree of pain, doctors often prescribe NSAIDs or acetaminophen (Tylenol). If you experience more acute pain, your doctor may prescribe an opioid and will progress you to other medications as your pain subsides. Opioids can be addictive, so most of the time, they will not prescribe them for longer than you need them.

What helps pain at night after knee replacement?

If pain is keeping you up, it can help to take your pain medication about an hour before going to bed and then set your alarm to make sure you remember to take your next dose of pain medication during the night.

Although it may seem counterintuitive to wake up to take the medication, this is a proactive approach to get ahead of your pain, which may keep you up for longer. You only have to wake up long enough to take your pain medication.

How long will I need pain medication after total knee replacement?

This can vary from person to person, but many people can begin to reduce their use of opioids within 6 weeks after surgery.

Knee replacement surgery can increase pain for a while, but the procedure can improve pain and mobility levels in the long term.

Medications can help keep pain to a minimum, and this can improve your mobility after surgery.

If you experience any symptoms or adverse effects after a knee replacement, it is best to speak to a doctor. They can often adjust a dose or change the medication.