Arixtra
fondaparinux sodium
Pharmacologic class: Selective factor Xa inhibitor
Therapeutic class: Anticoagulant, antithrombotic
Pregnancy risk category B
Action
Selectively inhibits factor Xa, disrupting blood coagulation and inhibiting thrombin formation and thrombus development
Availability
Injection: 2.5 mg/0.5 ml in single-dose syringe
Indications and dosages
➣ Prevention of deep-vein thrombosis after hip fracture surgery or hip or knee replacement surgery
Adults: 2.5 mg subcutaneously 6 to 8 hours after surgery, once hemostasis occurs; usual duration is 5 to 9 days (up to 11 days) given daily. After hip fracture surgery, extended prophylactic course of up to 24 additional days is recommended; some patients have tolerated a total course of 32 days.
➣ Deep-vein thrombosis and pulmonary emboli
Adults: 5 mg subcutaneously once daily for patients weighing less than 50 kg (110 lb), 7.5 mg subcutaneously for patients weighing 50 to 100 kg (110 to 220 lb) or 10 mg subcutaneously for patients weighing more than 100 kg (220 lb) for 5 days and until therapeutic oral anticoagulant effect occurs (as shown by International Normalized Ratio of 2 to 3). Usual duration of therapy is 5 to 9 days, but may continue for up to 26 days.
Dosage adjustment
• Renal impairment
Contraindications
• Hypersensitivity to drug
• Bacterial endocarditis
• Severe renal disease
• Active major bleeding
• Patients weighing less than 50 kg (110 lb) who have undergone hip fracture, hip replacement, or knee replacement surgery
Precautions
Use cautiously in:
• diabetic retinopathy, hepatic disease, blood dyscrasias, heparin-induced thrombocytopenia, severe hypertension, alcoholism
• patients older than age 75
• pregnant or breastfeeding patients
• children (safety and efficacy not established).
Administration
See Withhold for at least 6 to 8 hours after surgery, to minimize risk of major bleeding.
See Give by subcutaneous injection only. Don't give I.M.
• Rotate injection sites among fatty tissue areas on left and right anterolateral and posterolateral abdominal walls.
• Don't expel air bubble from syringe; doing so may reduce amount of drug delivered.
• Listen for slight click when plunger is fully released. After drug has been injected, needle retracts and white safety indicator is visible.
• Don't mix with other injections or infusions.
• Know that when drug is used to treat deep-vein thrombosis and pulmonary emboli, concomitant warfarin treatment should begin as soon as possible (usually within 72 hours).
Adverse reactions
CNS: depression, dizziness, asthenia, headache, abnormal thinking, confusion, insomnia, neuropathy
CV: hypotension
GI: nausea, vomiting, diarrhea, constipation, abdominal pain, dyspepsia, dry mouth, anorexia
GU: urinary retention, urinary tract infection
Hematologic: anemia, hematoma, purpura, minor bleeding, major bleeding, thrombocytopenia, retroperitoneal hemorrhage, postoperative hemorrhage
Metabolic: hypokalemia
Skin: bullous eruption
Other: increased wound drainage, injection site bleeding, pain, edema, fever
Interactions
Drug-drug. Anticoagulants: increased risk of bleeding
Drug-herbs. Anise, astragalus, bilberry, black currant, bladder wrack, bogbean, boldo, borage, buchu, capsaicin, cat's claw, celery, chaparral, cinchona, clove oil, dandelion, dong quai, fenugreek, feverfew, garlic, ginger, ginkgo, papaya, red clover, rhubarb, safflower oil, skullcap, tan-shen: additive anticoagulant effect
St. John's wort: reduced anticoagulant effect
Patient monitoring
• Monitor CBC, platelet count, creatinine level, and renal function tests. Assess stools for occult blood.
• Monitor vital signs, temperature, and fluid intake and output.
See Stay alert for bleeding tendency, especially postoperative hemorrhage.
• Check for increased wound drainage after surgery.
See In patient undergoing concomitant neuraxial anesthesia or spinal puncture, watch for neurologic impairment (indicating possible spinal or epidural hematoma).
See Discontinue drug if severe renal impairment occurs.
Patient teaching
See Instruct patient to immediately report bleeding.
• Caution patient to avoid activities that can cause injury. Tell him to use soft toothbrush and electric razor to avoid gum and skin injury.
• Tell patient that he'll undergo regular blood testing during therapy.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and herbs mentioned above.
fondaparinux
(fon-da-par-i-nux) fondaparinux,Arixtra
(trade name)Classification
Therapeutic: anticoagulantsPharmacologic: active factor x inhibitors
Indications
Action
Therapeutic effects
Pharmacokinetics
Time/action profile (anticoagulant effect)
| ROUTE | ONSET | PEAK | DURATION |
|---|---|---|---|
| Subcut | rapid | 3 hr | 24 hr |
Contraindications/Precautions
Adverse Reactions/Side Effects
Central nervous system
- confusion
- dizziness
- headache
- insomnia
Cardiovascular
- edema
- hypotension
Gastrointestinal
- constipation
- diarrhea
- dyspepsia
- ↑ liver enzymes
- nausea
- vomiting
Genitourinary
- urinary retention
Dermatologic
- bullous eruption
- hematoma
- purpura
- rash
Hematologic
- bleeding (most frequent)
- thrombocytopenia
Fluid and Electrolyte
- hypokalemia
Miscellaneous
- hypersensitivity reactions including angioedema (life-threatening)
- fever
- ↑ wound drainage
Interactions
Drug-Drug interaction
Risk of bleeding may be ↑ by concurrent use of warfarin or drugs that affect platelet function, including aspirin, NSAIDs, dipyridamole, some cephalosporins, valproates, clopidogrel, ticlopidine, abciximab, eptifibatide, tirofiban, and dextran.↑ risk of bleeding with arnica, chamomile, clove, dong quai, feverfew, garlic, ginger, gingko, Panax ginseng, and others.Route/Dosage
Treatment of DVT/PE
Prevention of DVT/PE
Availability (generic available)
Nursing implications
Nursing 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 prothrombin time (PT), activated thromboplastin time (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.
Potential Nursing Diagnoses
Ineffective tissue perfusion (Indications)Risk for injury (Side Effects)
Implementation
- 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.
- Subcutaneous: Administer subcut 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.
Evaluation/Desired Outcomes
- Prevention and treatment of deep vein thrombosis and pulmonary embolism.
Arixtra
A selective factor-Xa-inhibiting synthetic heparin anticoagulant, which is a pentasaccharide that covers the active site of heparin specific for antithrombin III.Indications
Prophylaxis of deep vein thrombosis (DVT) and PEs in hospitalised patients, including those with hip fractures and injuries, or patients undergoing total hip or total knee replacement surgery; it may be used to manage heparin-induced thrombocytopaenia (HIT).
Adverse effects
Bleeding, thrombocytopaenia, local reactions, increased aminotransferases.