fondaparinux

Absorption: 100% absorbed following SUBQ administration.

Distribution: Distributes mainly throughout the intravascular space.

Metabolism/Excretion: Eliminated mainly unchanged in urine.

Half-Life: 17–21 hr.

Time/Action Profile ⬆ ⬇

(anticoagulant effect)

ROUTE	ONSET	PEAK	DURATION
SUBQ	rapid	3 hr	24 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Severe renal impairment (↑ risk of bleeding);
Body weight <50 kg (for prophylaxis) (markedly ↑ risk of bleeding);
Active major bleeding;
Bacterial endocarditis;
Thrombocytopenia due to fondaparinux antibodies.

Use Cautiously in:

Mild to moderate renal impairment;
Untreated hypertension;
Recent history of ulcer disease;
Body weight <50 kg (for treatment of DVT or PE) (may ↑ risk of bleeding);
Malignancy;
History of heparin-induced thrombocytopenia;
OB: Use during pregnancy should be limited to those who have severe allergic reactions to heparin, including heparin-induced thrombocytopenia;
Lactation: Safety not established in breastfeeding;
Pedi: Children <1 yr (safety and effectiveness not established);
Geri: ↑risk of bleeding in older adults.

Exercise Extreme Caution in:

History of congenital or acquired bleeding disorder;
Severe uncontrolled hypertension;
Hemorrhagic stroke;
Recent CNS or ophthalmologic surgery;
Active GI bleeding/ulceration;
Retinopathy (hypertensive or diabetic);
Neuroaxial spinal anesthesia or spinal puncture, especially if concurrent with an indwelling epidural catheter; drugs affecting hemostasis; history of traumatic/repeated spinal puncture; or spinal deformity (↑ risk of spinal hematoma);

Adv. Reactions/Side Effects ⬆ ⬇

CV: edema, hypotension

Derm: bullous eruption, hematoma, purpura, rash

F and E: hypokalemia

GI: ↑liver enzymes, constipation, diarrhea, dyspepsia, nausea, vomiting

GU: urinary retention

Hemat: bleeding, thrombocytopenia

Neuro: confusion, dizziness, headache, insomnia

Misc: fever, HYPERSENSITIVITY REACTIONS (INCLUDING ANGIOEDEMA)

Interactions ⬆ ⬇

Drug-drug:

Warfarin or drugs that affect platelet function, including aspirin, NSAIDs, dipyridamole, some cephalosporins, valproates, clopidogrel, prasugrel, ticagrelor, eptifibatide, tirofiban, and dextran may ↑ risk of bleeding.

Drug-Natural Products:

↑risk of bleeding with arnica, chamomile, clove, dong quai, feverfew, garlic, ginger, gingko, Panax ginseng, and others.

Route/Dosage ⬆ ⬇

Treatment of Deep Vein Thrombosis/Pulmonary Embolism

SC (Adults >100 kg): 10 mg once daily for ≥5 days until therapeutic anticoagulation with warfarin is achieved (INR >2 for 2 consecutive days); warfarin may be started within 72 hr of fondaparinux.
SC (Adults 50–100 kg): 7.5 mg once daily for ≥5 days until therapeutic anticoagulation with warfarin is achieved (INR >2 for 2 consecutive days).
SC (Adults <50 kg): 5 mg once daily for ≥5 days until therapeutic anticoagulation with warfarin is achieved (INR >2 for 2 consecutive days); warfarin may be started within 72 hr of fondaparinux (has been used for up to 26 days).
SC (Children ≥1 yr and >60 kg): 7.5 mg once daily.
SC (Children ≥1 yr and >40–60 kg): 5 mg once daily. Adjust dose based on fondaparinux-based anti-Xa assay with a therapeutic goal range of 0.5–1 mg/L (not to exceed 7.5 mg/day).
SC (Children ≥1 yr and >20–40 kg): 2.5 mg once daily. Adjust dose based on fondaparinux-based anti-Xa assay with a therapeutic goal range of 0.5–1 mg/L (not to exceed 7.5 mg/day).
SC (Children ≥1 yr and 10–20 kg): 0.1 mg/kg (rounded to the nearest 0.1 mg) once daily. Adjust dose based on fondaparinux-based anti-Xa assay with a therapeutic goal range of 0.5–1 mg/L (not to exceed 7.5 mg/day).

Prevention of Deep Vein Thrombosis/Pulmonary Embolism

SC (Adults ): 2.5 mg once daily, starting 6–8 hr after surgery, continuing for 5–9 days (up to 11 days) following abdominal surgery or knee/hip replacement or continuing for 24 days following hip fracture surgery (up to 32 days).

Availability ⬆ ⬇

(Generic available)

Solution for injection (prefilled syringes): 2.5 mg/0.5 mL; 5 mg/0.4 mL; 7.5 mg/0.6 mL; 10 mg/0.8 mL

Assessment ⬆ ⬇

Assess for signs of bleeding and hemorrhage (bleeding gums; nosebleed; ↑ bruising; black, tarry, guaiac positive stools; hematuria; ↓ hematocrit; sudden ↓ in BP). If unexpected changes in coagulation parameters or major bleeding occurs, discontinue fondaparinux.
Assess for therapy effectiveness by monitoring for signs and symptoms of additional or ↑ thrombi.
Monitor neurological status frequently, especially in patients with indwelling epidural catheters or concurrent use of other drugs affecting hemostasis. Risk is ↑ by traumatic or repeated epidural or spinal puncture. May require urgent treatment.

Lab Test Considerations:

Monitor platelets closely. If platelets <100,000/mm³, discontinue fondaparinux.
- PT, aPTT, and international standards of heparin or low-molecular-weight heparins are not sensitive measures of the activity of fondaparinux.
- Monitor CBC and stool occult blood routinely during therapy.
- Assess renal function periodically during therapy. Anticoagulant effects may last >4 days after therapy discontinued in patients with renal impairment.
- May ↑ AST and ALT.
- May ↑ aPTT temporally associated with bleeding with or without concurrent administration of other anticoagulants and thrombocytopenia with thrombosis similar to heparin-induced thrombocytopenia.
Anti-factor Xa activity can be measured by anti-Xa assay, as clinically indicated.

Implementation ⬆ ⬇

High Alert: Do not confuse Arixtra with Arista AH (absorbable hemostatic agent).
Fondaparinux cannot be used interchangeably with heparin, low-molecular-weight heparins, or heparinoids.
- Initial dose should be administered 6–8 hr after surgery. Administration <6 hr after surgery carries ↑ risk of hemorrhage.
- Do not expel air bubble from prefilled syringe before injection to prevent loss of drug.
SC: Administer using single-dose prefilled syringe or pharmacist-prepared syringe if alternate dose is required. Inject SUBQ into fatty tissue, alternating sites between right and left anterolateral or posterolateral abdomen. Insert entire length of needle at 45° or 90° angle into a skin fold held between thumb and forefinger. Do not aspirate or massage. Rotate sites frequently. Do not administer IM. Solution is clear; do not use if cloudy or contains particulates. Do not mix with other injections.

Patient/Family Teaching ⬆ ⬇

Explain purpose and side effects of medication. Advise patient to read Patient Information before starting therapy. Instruct patient on appropriate steps for administration technique and disposal of equipment, if self-administration is appropriate.
Advise patient to report any symptoms of easy bleeding or bruising, dizziness, itching, rash, fever, swelling, or difficulty breathing to health care provider immediately.
Inform patient having had neuraxial anesthesia or spinal puncture to watch for signs and symptoms of spinal or epidural hematoma (numbness or weakness of legs, bowel or bladder dysfunction). Notify health care provider immediately if symptoms occur.
Instruct patient not to take aspirin or NSAIDs without consulting health care provider during therapy and to notify health care provider of all Rx or OTC medications, vitamins, or herbal products being taken and before taking other medications.
Inform patient that packaging contains latex and to notify health care provider of latex allergy prior to therapy initiation.
Rep: Advise women of reproductive potential to notify health care provider if pregnancy is planned or suspected or if breastfeeding.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇