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 (CCr <30 mL/min; ↑ 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 (CCr 30–50 mL/min);
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: Safety and effectiveness not established in children;
Geri: risk of bleeding in older adults.

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/epidural hematoma that may lead to long-term or permanent paralysis).

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:

Risk of bleeding may be ↑ by concurrent use of warfarin or drugs that affect platelet function, including aspirin, NSAIDs, dipyridamole, some cephalosporins, valproates, clopidogrel, prasugrel, ticagrelor, eptifibatide, tirofiban, and dextran.

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 at least 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 at least 5 days until therapeutic anticoagulation with warfarin is achieved (INR >2 for 2 consecutive days).
SC (Adults <50 kg): 5 mg once daily for at least 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).

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; unusual bruising; black, tarry stools; hematuria; fall in hematocrit; sudden drop in BP; guaiac positive stools); bleeding from surgical site. Notify health care professional if these occur.
Assess for evidence of additional or increased thrombosis. Symptoms will depend on area of involvement. Monitor neurological status frequently for signs of impairment, especially in patients with indwelling epidural catheters for administration of analgesia or with concomitant use of drugs affecting hemostasis (NSAIDs, platelet inhibitors, other anticoagulants). Risk is increased by traumatic or repeated epidural or spinal puncture. May require urgent treatment.

Lab Test Considerations:

Monitor platelet count closely; may cause thrombocytopenia. If platelet count is <100,000/mm³, discontinue fondaparinux.
- Fondaparinux is not accurately measured by PT, activated aPTT, or international standards of heparin or low-molecular-weight heparins. If unexpected changes in coagulation parameters or major bleeding occurs, discontinue fondaparinux.
- Monitor CBC, serum creatinine levels, and stool occult blood tests routinely during therapy.
- May cause asymptomatic ↑ in AST and ALT. Elevations are fully reversible and not associated with ↑ in bilirubin.
- May cause ↑ aPTT temporally associated with bleeding with or without concomitant administration of other anticoagulants and thrombocytopenia with thrombosis similar to heparin-induced thrombocytopenia, with or without exposure to heparin or low-molecular-weight heparins.

Implementation ⬆ ⬇

Do not confuse Arixtra with Arista AH (absorbable hemostatic agent).
Fondaparinux cannot be used interchangeably with heparin, low-molecular-weight heparins, or heparinoids as they differ in manufacturing process, anti-Xa and anti-IIa activity, units, and dose. Each of these medications has its own instructions for use.
- Initial dose should be administered 6–8 hr after surgery. Administration before 6 hr after surgery has been associated with risk of major bleeding.
SC: Administer SUBQ only into fatty tissue, alternating sites between right and left anterolateral or posterolateral abdominal wall. Inject entire length of needle at a 45° or 90° angle into a skin fold held between thumb and forefinger; hold skin fold throughout injection. Do not aspirate or massage. Rotate sites frequently. Do not administer IM because of danger of hematoma formation. Solution should be clear; do not inject solution containing particulate matter. Do not mix with other injections.
- Fondaparinux is provided in a single-dose prefilled syringe with an automatic needle protection system. Do not expel air bubble from prefilled syringe before injection to prevent loss of drug.

Patient/Family Teaching ⬆ ⬇

Advise patient to report any symptoms of unusual bleeding or bruising, dizziness, itching, rash, fever, swelling, or difficulty breathing to health care professional immediately.
Instruct patient not to take aspirin or NSAIDs without consulting health care professional during therapy.
Rep: Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.

section name header

Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇