What is the recommended dosage of Lovenox (enoxaparin) for Venous Thromboembolism (VTE) prophylaxis in a 75-year-old patient with impaired renal function, specifically a creatinine clearance of 35, indicating severe renal impairment?

From the Guidelines

For VTE prophylaxis in a 75-year-old patient with a creatinine clearance of 35 mL/min, the recommended Lovenox (enoxaparin) dosage is 30 mg subcutaneously once daily. This dosage is based on the patient's severe renal impairment, as indicated by a creatinine clearance of 35 mL/min. According to the manufacturer's recommendations, for patients with severe renal insufficiency (creatinine clearance <30 mL/min), the recommended dose of enoxaparin for VTE prophylaxis is 30 mg subcutaneously once daily 1.

Key Considerations

• Enoxaparin is primarily eliminated by the kidneys, and reduced clearance in elderly patients with decreased renal function increases the risk of bleeding complications.
• The medication should be administered at the same time each day, typically in the morning, with the injection given in the abdominal area at least 2 inches away from the navel.
• Monitor the patient for signs of bleeding and periodically check anti-Xa levels if therapy is prolonged.
• Also, assess renal function regularly, as further decline may necessitate additional dose adjustments.
• Platelet counts should be monitored for heparin-induced thrombocytopenia, particularly during the first two weeks of therapy.

Rationale

The recommended dosage is supported by the results of a meta-analysis showing enoxaparin to be associated with a 2- to 3-fold increased risk of bleeding when administered in standard, unadjusted therapeutic doses to patients with severe renal insufficiency compared with those without severe renal insufficiency 1. Additionally, renal clearance of enoxaparin was shown to be reduced by 31% and 44% in patients with moderate (30–60 mL/min) and severe renal impairment (<30 mL/min), respectively, leading the authors to suggest dose reductions for patients with CCr values less than 50 mL/min 1.

Comparison with Other Guidelines

Other guidelines, such as those from the American Heart Association, also recommend adjusting the dose of enoxaparin in patients with renal impairment 1. However, the most recent and highest-quality study, which is the primary consideration for this recommendation, is from the Journal of the National Comprehensive Cancer Network 1.

Conclusion is not provided as per the guidelines, the answer is provided in the above paragraphs.

From the Research

Dosage Recommendations for Lovenox (Enoxaparin) in Patients with Severe Renal Impairment

The recommended dosage of Lovenox (enoxaparin) for Venous Thromboembolism (VTE) prophylaxis in patients with severe renal impairment is not explicitly stated in the provided studies. However, some studies provide guidance on dosage adjustments for patients with renal impairment:

• A study published in 2005 2 suggests that dose adjustment of anticoagulants may be indicated when the creatinine clearance falls below 30 mL/min.
• A study published in 2019 3 evaluated the efficacy of daily subcutaneous enoxaparin 20 mg in patients with renal failure, including those with a creatinine clearance rate of <30 mL/minute.

Considerations for Patients with Severe Renal Impairment

When considering the use of enoxaparin in patients with severe renal impairment, the following factors should be taken into account:

• The risk of bleeding complications, which may be increased in patients with severe renal impairment 4
• The potential for drug accumulation, which may increase the risk of bleeding 4
• The need for close monitoring of anticoagulation and renal function 2

Specific Guidance for a 75-year-old Patient with a Creatinine Clearance of 35

Based on the available evidence, the following guidance can be provided:

• A study published in 2019 3 found that enoxaparin 20 mg SC daily resulted in a 5.6% incidence of VTE in patients with renal failure, which is similar to the previously published acceptable incidence of VTE in patients with normal renal function receiving enoxaparin 40 mg SC daily.
• The same study found that the incidence of major bleeding events was 10%, which is lower than that previously published in the literature.
• However, the study also found that an age of >75 years was significantly associated with an increased risk of bleeding 3.