When should patients stop taking meloxicam, aspirin (acetylsalicylic acid), and metformin before undergoing total knee replacement surgery?

Perioperative Medication Management for Total Knee Replacement

For patients undergoing total knee replacement surgery, meloxicam should be stopped 20 hours before surgery, aspirin management depends on cardiovascular risk (continue for high-risk patients, stop 7-10 days before surgery for low-risk patients), and metformin can be continued until the day before surgery. 1, 2

Meloxicam Management

• Discontinuation timing: Stop meloxicam approximately 20 hours before surgery

  • Meloxicam has a half-life of approximately 20 hours 1
  • As a nonsteroidal anti-inflammatory drug with reversible antiplatelet properties, it requires at least one half-life for significant clearance

• Rationale: Discontinuation reduces the risk of perioperative bleeding complications

  • NSAIDs impair platelet function and can increase surgical bleeding
  • Allowing one half-life for clearance balances bleeding risk while not being excessively cautious

Aspirin (ASA) Management

• For patients at moderate to high risk for cardiovascular events:

  • Continue aspirin throughout the perioperative period 1, 2
  • High-risk patients include those with recent coronary stents, history of myocardial infarction, or high ASCVD risk

• For patients at low risk for cardiovascular events:

  • Stop aspirin 7-10 days before surgery 1
  • This allows for complete restoration of platelet function

• Special considerations:

  • Patients with coronary stents require special attention - consult cardiology before discontinuing 2
  • For bare-metal stents, defer elective surgery for at least 6 weeks after placement 2
  • For drug-eluting stents, defer elective surgery for at least 6 months after placement 2

• Evidence on continuing aspirin:

  • Some studies suggest that continuing aspirin during TKA may be associated with slightly higher bleeding but lower vascular-related complications 3, 4
  • Recent evidence indicates aspirin may be as effective as anticoagulants for VTE prophylaxis in knee replacements 5

Metformin Management

• Standard recommendation: Continue metformin until the day before surgery

  • Unlike medications affecting coagulation, metformin does not directly increase bleeding risk
  • Discontinue the evening before or morning of surgery to prevent hypoglycemia during the fasting period

• Special considerations:

  • For patients with renal impairment, consider earlier discontinuation (48 hours before) to prevent metformin accumulation
  • Resume metformin when oral intake is established and renal function is stable

Postoperative Resumption

• Meloxicam: Resume 24-48 hours after surgery once adequate hemostasis is achieved and renal function is stable

• Aspirin:

  • If continued perioperatively: Continue without interruption
  • If discontinued: Resume within 24-48 hours after surgery once adequate hemostasis is achieved 2

• Metformin: Resume when patient is eating normally and renal function is stable (typically 24-48 hours post-surgery)

Common Pitfalls to Avoid

1. Failing to assess cardiovascular risk when deciding on aspirin management
2. Stopping meloxicam too early (more than 24 hours before surgery), which may lead to unnecessary pain
3. Stopping metformin too early in patients with normal renal function
4. Not considering patient-specific factors such as age, weight, and concomitant medications that may affect drug clearance 2
5. Forgetting to restart medications in a timely manner postoperatively

By following these evidence-based recommendations, you can optimize perioperative medication management to reduce both bleeding risk and the risk of cardiovascular events in patients undergoing total knee replacement.