Prescription medication · Factor Xa Inhibitor (Injectable)

fondaparinux

Also sold as Arixtra. This medicine can prevent deep vein thrombosis (DVT) after hip fracture, hip replacement, knee replacement, or abdominal surgery.

Data updated 2026-05-15

7,980
FDA reportsLightly reported
3
InteractionsFew interactions
In shortage
FDA status

What the data shows

fondaparinux (Arixtra) is a prescription Factor Xa Inhibitor (Injectable), reported less often than most tracked drugs (7,980 FDA reports), with 3 documented drug interactions.

Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.

fondaparinux (Arixtra) is a prescription Factor Xa Inhibitor (Injectable). This medicine can prevent deep vein thrombosis (DVT) after hip fracture, hip replacement, knee replacement, or abdominal surgery.

Fondaparinux is a drug that helps prevent and treat blood clots. It is given as an injection under the skin.

Drug Shortage Alert

fondaparinux is currently listed as to be discontinued by the FDA. Affected manufacturer: Jiangsu Hengrui Pharmaceuticals Co. (US Agent eVenus Pharmaceutical Laboratories, Inc.).

View all drug shortages →

Drug Pricing (NADAC)

Generic Price

$17.08/unit

Generic Available

Yes (4 manufacturers)

Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →

Compare with Another Drug → Full Side Effects Report →

What it does

This medicine can prevent deep vein thrombosis (DVT) after hip fracture, hip replacement, knee replacement, or abdominal surgery.

Common side effects

Bleeding

Key warnings

This medicine can cause bleeding around your spine if you get an epidural or spinal tap while taking it.

The sections below are summarized in plain English from fondaparinux's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.

How It Works

Fondaparinux is a Factor Xa inhibitor. It works by blocking a substance in your blood called Factor Xa. Blocking Factor Xa helps to prevent blood clots from forming.

Side Effects (from patient reports)

Based on 7,980 FDA adverse event reports.

Most-reported reactions

Adverse reactions in FAERS for fondaparinux, by number of reports

reports

What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.

Source FDA Adverse Event Reporting System (FAERS) As of 2025

Reports over time

Adverse-event reports filed for fondaparinux each year to the FDA Adverse Event Reporting System (FAERS).

02004006008001,000 20042007201020132016201920222025 145

Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.

Where fondaparinux sits

fondaparinux has more FDA adverse-event reports than 35% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.

fewest reports most reports

Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is fondaparinux; the line is the median (50th percentile).

FDA Adverse Event Report Analysis

Detailed analysis of 7,980 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.

Total Reports

7,980

Reports Mentioning Death

1,436

18.0% of reports — not proof of cause

Hospitalization Reports

4,235

Top Indication

Product Used For Unknown Indication

Gender Distribution

Female 4,133 (56%)
Male 3,157 (43%)

Age Distribution

0–17 65
18–44 668
45–64 1,615
65–74 1,289
75+ 1,683

Most Reported Adverse Reactions (FAERS)

# Reaction Reports
1 ANAEMIA 610
2 HAEMATOMA 558
3 PULMONARY EMBOLISM 441
5 HAEMORRHAGE 348
6 HAEMOGLOBIN DECREASED 335
7 DEATH 296
8 DEEP VEIN THROMBOSIS 293
9 DYSPNOEA 269
10 THROMBOCYTOPENIA 260
12 PYREXIA 240
13 NAUSEA 234
14 THROMBOSIS 233
15 VOMITING 230
16 DRUG INTERACTION 228
17 MUSCLE HAEMORRHAGE 215

Reactions in Death Reports

DEATH 294
CEREBRAL HAEMORRHAGE 124
PULMONARY EMBOLISM 117
ANAEMIA 84
HAEMORRHAGE 78
SHOCK HAEMORRHAGIC 76
HAEMATOMA 69
SEPSIS 69
COMA 62
THROMBOCYTOPENIA 61

Reactions in Hospitalization Reports

ANAEMIA 476
HAEMATOMA 429
PULMONARY EMBOLISM 270
HAEMOGLOBIN DECREASED 221
DYSPNOEA 191
DEEP VEIN THROMBOSIS 190
ABDOMINAL PAIN 177
MUSCLE HAEMORRHAGE 172
THROMBOCYTOPENIA 169
HAEMORRHAGE 165

Source: FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation

Serious Warnings

This medicine can cause bleeding around your spine if you get an epidural or spinal tap while taking it. This bleeding can cause long-term or permanent paralysis. Tell your doctor if you are scheduled for a spinal procedure. Watch for signs of nerve damage like back pain, numbness, tingling, or weakness in your legs, or problems with bowel or bladder control. If you notice any of these symptoms, get medical help right away.

Known Drug Interactions

7 DRUG INTERACTIONS In clinical studies performed with fondaparinux sodium, the concomitant use of oral anticoagulants (warfarin), platelet inhibitors (acetylsalicylic acid), NSAIDs (piroxicam), and digoxin did not significantly affect the pharmacokinetics/pharmacodynamics of fondaparinux sodium. In addition, fondaparinux sodium neither influenced the pharmacodynamics of warfarin, acetylsalicylic acid, piroxicam, and digoxin, nor the pharmacokinetics of digoxin at steady state.

Mechanism: These drugs do not change how the body handles each other or how well they work to thin the blood.

minor digoxin

7 DRUG INTERACTIONS In clinical studies performed with fondaparinux sodium, the concomitant use of oral anticoagulants (warfarin), platelet inhibitors (acetylsalicylic acid), NSAIDs (piroxicam), and digoxin did not significantly affect the pharmacokinetics/pharmacodynamics of fondaparinux sodium. In addition, fondaparinux sodium neither influenced the pharmacodynamics of warfarin, acetylsalicylic acid, piroxicam, and digoxin, nor the pharmacokinetics of digoxin at steady state.

Mechanism: These medicines do not interfere with each other's levels or how they function in the body.

7 DRUG INTERACTIONS In clinical studies performed with fondaparinux sodium, the concomitant use of oral anticoagulants (warfarin), platelet inhibitors (acetylsalicylic acid), NSAIDs (piroxicam), and digoxin did not significantly affect the pharmacokinetics/pharmacodynamics of fondaparinux sodium. In addition, fondaparinux sodium neither influenced the pharmacodynamics of warfarin, acetylsalicylic acid, piroxicam, and digoxin, nor the pharmacokinetics of digoxin at steady state.

Mechanism: These drugs do not have a significant impact on how the other is absorbed or used by the body.

This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.

Common Questions

What should I avoid while taking fondaparinux?
Talk to your doctor before taking other medicines that can increase your risk of bleeding, like NSAIDs (such as ibuprofen or naproxen), aspirin, or other blood thinners.
How will I know if I'm bleeding too much?
Watch for signs of bleeding, such as unusual bruising, nosebleeds, bleeding gums, blood in your urine or stool, or heavy menstrual bleeding. Tell your doctor right away if you notice any of these signs.
Can I take fondaparinux if I have kidney problems?
You should not take fondaparinux if you have severe kidney problems. Talk to your doctor about whether this medicine is right for you if you have kidney problems.
Will fondaparinux interact with my other medications?
Fondaparinux does not usually interact with many medications. However, it is important to tell your doctor about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.
How long will I need to take fondaparinux?
The length of treatment depends on why you are taking fondaparinux. For DVT prevention after surgery, it is usually taken for 5 to 9 days. For hip fracture surgery, it may be taken for up to 32 days.
Can fondaparinux cause an allergic reaction?
In rare cases, fondaparinux can cause a serious allergic reaction. Get medical help right away if you have any signs of an allergic reaction, such as hives, difficulty breathing, or swelling of your face, lips, tongue, or throat.
What should I do before any surgery or dental procedure?
Tell your doctor or dentist that you are taking fondaparinux before any surgery or dental procedure. You may need to stop taking it for a short time before the procedure to reduce your risk of bleeding.
Can I drink alcohol while taking fondaparinux?
Talk to your doctor about whether it is safe for you to drink alcohol while taking fondaparinux. Alcohol can increase your risk of bleeding.
What if I accidentally inject too much fondaparinux?
If you inject too much fondaparinux, get medical help right away. Overdosing on fondaparinux can increase your risk of serious bleeding.
Will fondaparinux make me feel tired?
Fondaparinux does not commonly cause tiredness. If you feel unusually tired, talk to your doctor.
What are the common side effects of fondaparinux?
The registry lists Bleeding among the most-reported FAERS reaction terms for fondaparinux. The compiled record contains 7,980 FDA adverse-event reports. These counts are not an individual symptom assessment.
Does fondaparinux interact with other medications?
The registry has 3 documented interaction rows for fondaparinux. Notable source-record pairings include warfarin, digoxin, piroxicam. These rows are not a complete medication review.
What drug class is fondaparinux?
fondaparinux belongs to the Factor Xa Inhibitor (Injectable) drug class. It requires a prescription (Rx). This medicine can prevent deep vein thrombosis (DVT) after hip fracture, hip replacement, knee replacement, or abdominal surgery.
What pregnancy or breastfeeding source fields are listed for fondaparinux?
The FDA label for fondaparinux contains product-specific pregnancy or breastfeeding language. PlainMeds does not apply that source text to an individual.
Is fondaparinux currently in shortage?
Yes, fondaparinux is currently listed as to be discontinued by the FDA. Affected manufacturer: Jiangsu Hengrui Pharmaceuticals Co. (US Agent eVenus Pharmaceutical Laboratories, Inc.). Visit the FDA Drug Shortages database for the latest updates.

Other drugs grouped near fondaparinux - same-class peers and common alternatives.

Compare fondaparinux vs apixaban side-by-side →

Compare beyond drug class

Nationwide peers by FAERS volume & death-report share

Two PlainMeds-derived comparison paths for fondaparinux: nearest FDA FAERS report volume and nearest death-report share among drugs with at least 1,000 logged reports, excluding same-class neighbors listed above. Counts reflect reporting volume, not proven individual harm.

Medication Guides

Save on fondaparinux

Compare prices and find discounts at pharmacies near you. Free coupons can save up to 80% on prescriptions.

Disclosure: This link may earn us a commission at no extra cost to you. See our terms.

What the FDA Data Shows for fondaparinux

The FDA label for fondaparinux (sold under brand names such as Arixtra) classifies it as a prescription-only medication in the Factor Xa Inhibitor (Injectable) class. This medicine can prevent deep vein thrombosis (DVT) after hip fracture, hip replacement, knee replacement, or abdominal surgery. Official labeling lists 1 commonly reported side effect, including Bleeding.

Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 7,980 voluntary reports. The database also lists 3 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated minor severity. NADAC pricing from CMS shows a generic unit cost of $17.08.

Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.

Data Sources

Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC). Shortage status: FDA Drug Shortages Database.

FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.

Last updated: September 10, 2021

PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.

Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.

All federal data sources used on this page