How to administer Clexane (enoxaparin)?

How to Administer Clexane (Enoxaparin)

Administer enoxaparin subcutaneously in the anterolateral or posterolateral abdominal wall, alternating injection sites between the left and right sides, using proper technique to minimize bruising and ensure optimal absorption. 1

Injection Technique and Site Selection

Preferred Injection Sites

• Inject into the anterolateral or posterolateral abdominal wall, avoiding the area within 2 inches (5 cm) of the umbilicus and the belt line 1
• Alternate between left and right sides with each injection to minimize local tissue trauma 1
• Avoid areas with scars, bruises, or skin abnormalities 1

Step-by-Step Administration Technique

Preparation:

• Have the patient lie down or sit comfortably to relax the abdominal wall 1
• Do not expel the air bubble from prefilled syringes, as this ensures accurate dosing 1
• Clean the injection site with alcohol and allow to dry 1

Injection Process:

• Pinch a fold of skin between thumb and forefinger to create a subcutaneous pocket 1
• Insert the needle at a 90-degree angle (perpendicular to the skin fold) to its full length 1
• Inject the medication slowly while maintaining the skin fold 1
• Do not aspirate before injecting, as this increases bruising risk 1
• Withdraw the needle quickly after injection and release the skin fold 1
• Do not rub or massage the injection site, as this increases bruising and may affect absorption 1

Dosing Regimens by Indication

For Venous Thromboembolism Treatment

• Standard therapeutic dosing: 1 mg/kg subcutaneously every 12 hours 1
• Alternative once-daily regimen: 1.5 mg/kg subcutaneously once daily 1
• Continue for minimum 5 days and overlap with warfarin until INR is ≥2.0 for at least 24 hours 1

For VTE Prophylaxis

• Standard prophylactic dose: 40 mg subcutaneously once daily 1, 2
• High-risk patients (>150 kg): Consider 40 mg every 12 hours 2
• Initiate 2-4 hours before surgery or 10-12 hours before neuraxial anesthesia 2

For Acute Coronary Syndromes with Fibrinolysis

• Patients <75 years: 30 mg IV bolus, followed 15 minutes later by 1 mg/kg subcutaneously every 12 hours (maximum 100 mg for first two doses) 1
• Patients ≥75 years: No IV bolus; start with 0.75 mg/kg subcutaneously every 12 hours (maximum 75 mg for first two doses) 1
• Continue for duration of hospitalization, up to 8 days 1

For Primary PCI

• 0.5 mg/kg IV bolus at time of procedure 1
• If last subcutaneous dose was within 8 hours, no additional dose needed 1
• If last dose was 8-12 hours prior, give 0.3 mg/kg IV 1

Critical Dose Adjustments

Severe Renal Impairment (CrCl <30 mL/min)

• Therapeutic dosing: Reduce to 1 mg/kg subcutaneously once daily (every 24 hours) 1, 3
• Prophylactic dosing: Reduce to 30 mg subcutaneously once daily 1, 3, 2
• This adjustment is mandatory due to 2-3 fold increased bleeding risk without dose reduction 3

Elderly Patients (≥75 years) with ACS

• Eliminate the IV bolus entirely 1
• Use 0.75 mg/kg subcutaneously every 12 hours regardless of renal function 1, 3

Obesity Considerations

• For prophylaxis in patients >150 kg, consider 40 mg every 12 hours 2
• For therapeutic dosing, use standard weight-based dosing (1 mg/kg every 12 hours) 1
• Consider anti-Xa monitoring in morbidly obese patients 3, 2

Timing Considerations with Procedures

Neuraxial Anesthesia

• Withhold enoxaparin for 10-12 hours before neuraxial anesthesia to prevent spinal hematoma 3, 2
• For prophylactic dosing (40 mg daily), may resume 4 hours after catheter removal but not before 12 hours after the block 2
• For therapeutic dosing, may resume 4 hours after catheter removal but not before 24 hours after the block 2

Transitioning to PCI

• If receiving enoxaparin and undergoing PCI within 8 hours of last dose, no additional anticoagulation needed 1
• If 8-12 hours since last dose, give 0.3 mg/kg IV bolus 1
• Do not add unfractionated heparin to patients already on enoxaparin, as this increases bleeding without benefit 3

Monitoring Requirements

Anti-Xa Level Monitoring

• Measure 4 hours after the dose (peak level) 3
• Only after 3-4 doses have been administered to reach steady state 3
• Target therapeutic range: 0.5-1.5 IU/mL 3

When to Monitor Anti-Xa Levels

• Severe renal impairment (CrCl <30 mL/min) receiving prolonged treatment 3
• Morbid obesity 3, 2
• Extremes of body weight (<50 kg or >150 kg) 3
• Pregnancy with therapeutic dosing 2
• Elderly patients (≥70 years) with renal insufficiency 3

Platelet Monitoring

• Monitor platelet counts regularly during treatment due to risk of heparin-induced thrombocytopenia 3
• Check baseline, then every 2-3 days during first 2 weeks, then periodically 3

Common Pitfalls and How to Avoid Them

Critical Errors to Avoid

• Never switch between enoxaparin and unfractionated heparin mid-treatment, as this increases bleeding risk 3
• Never use standard 1 mg/kg every 12 hours in severe renal impairment without reducing to once daily 3
• Never inject into areas other than the abdomen (except in rare circumstances), as absorption is less predictable 1
• Never expel the air bubble from prefilled syringes, as this leads to underdosing 1
• Never massage the injection site, as this increases bruising and may affect drug absorption 1

Special Population Considerations

• In trauma patients, generally withhold for 2-3 days, then reassess risk-benefit before initiating 2
• Avoid tinzaparin entirely in elderly patients (≥70 years) with renal insufficiency due to substantially higher mortality rates 3
• For pregnant women with combined thrombophilic defects, doses up to 80 mg/day have been studied 4

Storage and Handling

• Store at room temperature; do not freeze 1
• Prefilled syringes are single-use only; discard any unused portion 1
• Check for particulate matter or discoloration before administration 1