Medication plays an important role in a knee replacement procedure. Here are some of the medications your doctor will likely prescribe during and after your hospital stay:

Pain Medications

During Your Hospital Stay

During a procedure and immediately afterward, you will receive pain medication intravenously. The typical drugs used—called opioid pain relievers—include morphine, fentanyl, and oxycodone. They are delivered through the same IV catheter that provides hydration, sedatives, and anesthesia. You may also receive the option of administering your own doses of medication using a patient-controlled analgesia (PCA) system. When you feel increased pain, this system allows you to push a button to receive a fixed dose of the pain medication. A PCA prevents you from taking more than the prescribed amount by limiting the time frame and amount of medication you can self-administer.

After You Are Released from the Hospital

Your surgeon will likely prescribe oral pain medication that you will take for up to several weeks. The most common drugs that surgeons recommend are prescription-strength, non-steroidal, anti-inflammatory drugs (NSAIDs) that you take by mouth, such as ibuprofen or naproxen. These reduce swelling and soreness while causing relatively few side effects. If you experience more severe pain, your doctor may prescribe opioid pain relievers, similar to what you received in your IV drip during surgery, except that they will be taken by mouth  However, extended use of these drugs is not recommended because they are highly addictive.


To minimize the risk of an infection, your doctor will administer antibiotics. A serious infection can occur if bacteria travel through your bloodstream to your newly replaced joint. Antibiotics help your body resist bacteria and prevent infections. Your surgeon will administer antibiotics before, during, and after surgery. In addition, for at least the next two years following a knee replacement, you will likely receive preventive antibiotics to take before any dental or surgical procedures. During this time, the risk of infection is higher because your tissues need time to bond with the implant. Those with immune disorders such as HIV, insulin-dependent diabetes, hemophilia, or a malignancy, as well as those with lupus or rheumatoid arthritis, will also require extended use of antibiotics.

Blood Thinners

Also known as anticoagulants, blood thinners slow the blood’s ability to coagulate or clot.  Surgery or injury of any kind naturally increases the risk of a blood clot because the trauma caused by these events stimulates your body’s clotting process. There’s a high likelihood that you will be given blood thinners such as warfarin (Coumadin), rivaroxaban (Xarelto), heparin, or enoxaparin (Lovenox) as a preventive measure to reduce the risk of blood clots after surgery. Most patients take blood-thinning medication for several weeks following their knee replacement. 

Blood clots—also called deep vein thrombosis—are common in the legs after TKR surgery. They are experienced by more than half of all knee replacement patients. If any of these clots dislodge and travel to the lungs, they can cause a pulmonary embolism—a dangerous and potentially fatal condition. As a result, it’s important to move the leg and stimulate blood flow immediately after surgery and then to continue to regularly exercise the leg for several weeks afterward. If you do not move your leg, you are at higher risk of a blood clot.

Drug Allergies and Interactions

It is important to review your allergies as well as any medications you currently take with your doctor prior to surgery. That way, your medical team can take the necessary steps to reduce the risk of complications.