Inhixa: Uses, Dosage & Side Effects

What Is Inhixa and What Is It Used For?

Inhixa contains the active substance enoxaparin sodium, a low-molecular-weight heparin (LMWH) with a mean molecular weight of approximately 4,500 daltons (range 3,800 to 5,000 daltons). It is produced by alkaline depolymerization of the benzyl ester derivative of unfractionated heparin obtained from porcine intestinal mucosa. Unlike unfractionated heparin (UFH), which contains a heterogeneous mixture of polysaccharide chains with molecular weights ranging from 3,000 to 30,000 daltons, enoxaparin has been processed to yield shorter, more uniform chains that provide a more predictable anticoagulant response.

Inhixa is a biosimilar medicine, meaning it has been developed to be highly similar to an already authorized biological medicine known as the reference product (Clexane/Lovenox, originally manufactured by Sanofi). The European Medicines Agency (EMA) approved Inhixa in 2016 after extensive comparative studies demonstrated equivalent quality, safety, and efficacy to the reference product. Biosimilar enoxaparin products have significantly improved access to this essential anticoagulant therapy by providing more affordable alternatives while maintaining the same therapeutic standards.

The mechanism of action of enoxaparin centres on its interaction with antithrombin III (AT-III), a naturally occurring serine protease inhibitor in the blood. When enoxaparin binds to AT-III, it dramatically accelerates the rate at which AT-III can neutralize activated clotting factors, particularly factor Xa (anti-Xa activity) and, to a lesser extent, thrombin or factor IIa (anti-IIa activity). The ratio of anti-Xa to anti-IIa activity for enoxaparin is approximately 3.6:1, compared to approximately 1:1 for unfractionated heparin. This preferential anti-Xa activity is clinically significant because factor Xa occupies a central position in the coagulation cascade, sitting at the convergence of both the intrinsic and extrinsic pathways, and its inhibition provides potent anticoagulation while potentially reducing the risk of bleeding complications.

Enoxaparin has several pharmacological advantages over unfractionated heparin that have made it the preferred anticoagulant in many clinical settings. These include higher and more consistent bioavailability after subcutaneous injection (approximately 100% compared to approximately 30% for UFH), a longer plasma half-life (4 to 5 hours after a single dose, extending to approximately 7 hours after repeated dosing), a more predictable dose-response relationship that typically eliminates the need for routine coagulation monitoring, and a lower incidence of heparin-induced thrombocytopenia (HIT). These properties allow for convenient once- or twice-daily subcutaneous dosing, often enabling outpatient treatment of conditions that previously required hospitalization for intravenous heparin infusion.

Inhixa is indicated for the following clinical conditions:

• Prophylaxis of venous thromboembolism (VTE): Prevention of deep vein thrombosis in surgical patients, particularly those undergoing orthopaedic surgery (hip or knee replacement), abdominal surgery, or other major surgical procedures with moderate to high thrombotic risk. VTE prophylaxis is also indicated for medical patients who are bedridden due to acute illness, including heart failure, acute respiratory failure, or acute infections.
• Treatment of deep vein thrombosis (DVT): Treatment of established DVT, with or without pulmonary embolism. Enoxaparin is used as the initial treatment phase, typically overlapping with the initiation of oral anticoagulant therapy (warfarin or direct oral anticoagulants).
• Prevention of clot formation during hemodialysis: Enoxaparin is administered into the arterial line of the dialysis circuit to prevent clotting of blood in the extracorporeal circulation during hemodialysis sessions.
• Acute coronary syndromes: Treatment of unstable angina and non-ST-elevation myocardial infarction (NSTEMI), in combination with acetylsalicylic acid (aspirin). Enoxaparin is also used in the treatment of acute ST-elevation myocardial infarction (STEMI), including patients managed medically or with subsequent percutaneous coronary intervention (PCI).

Enoxaparin sodium is listed on the World Health Organization (WHO) Model List of Essential Medicines, reflecting its fundamental importance in healthcare systems worldwide. Its inclusion underscores the extensive clinical evidence supporting its efficacy and safety across multiple indications, accumulated over more than three decades of clinical use since the original reference product was first approved in 1987.

What Should You Know Before Taking Inhixa?

Contraindications

Inhixa must not be used in the following situations, as the risks significantly outweigh any potential benefits:

• Hypersensitivity: Known allergy to enoxaparin sodium, heparin, or any heparin derivative, including other low-molecular-weight heparins. Since enoxaparin is derived from porcine intestinal mucosa, patients with known allergies to pork or pork-derived products should not use this medication. Serious allergic reactions can include anaphylaxis, urticaria, and angioedema.
• History of heparin-induced thrombocytopenia (HIT): Patients with a confirmed or suspected history of immune-mediated HIT within the past 100 days or who have circulating antibodies. HIT is a serious immune-mediated condition where heparin paradoxically triggers platelet activation and potentially life-threatening thrombosis.
• Active major bleeding: Any current condition associated with a high risk of uncontrolled haemorrhage, including active gastrointestinal bleeding, intracranial haemorrhage, or disseminated intravascular coagulation (DIC) attributable to heparin.
• Conditions with high bleeding risk: Active peptic ulcer disease, recent haemorrhagic stroke, severe uncontrolled arterial hypertension, bacterial endocarditis, or recent neurosurgery or ophthalmic surgery where haemorrhage could have catastrophic consequences.

Warnings and Precautions

The following precautions should be carefully considered before and during treatment with Inhixa:

• Haemorrhagic risk: Enoxaparin should be used with extreme caution in conditions with an increased potential for bleeding, including haemostatic disorders, hepatic insufficiency, history of peptic ulcer disease, recent ischaemic stroke, diabetic retinopathy, and concurrent use of medications that affect haemostasis. Any unexplained fall in haematocrit or blood pressure should be considered a sign of bleeding and investigated promptly.
• Renal impairment: Because enoxaparin is primarily eliminated by the kidneys, patients with reduced renal function are at increased risk of drug accumulation and bleeding. Dose reduction is required in patients with severe renal impairment (creatinine clearance below 30 mL/min). Monitoring of anti-Xa levels may be considered in patients with moderate renal impairment (creatinine clearance 30–50 mL/min).
• Body weight extremes: Low-body-weight women (less than 45 kg) and low-body-weight men (less than 57 kg) may experience greater exposure to enoxaparin at prophylactic doses and should be monitored carefully. Similarly, obese patients may require dose adjustment, and anti-Xa monitoring may be warranted.
• Thrombocytopenia: Platelet counts must be obtained before initiating enoxaparin therapy and monitored regularly throughout treatment. Enoxaparin should be discontinued immediately if platelet counts fall below 100,000/mm³ or if there is evidence of HIT. Both early-onset mild thrombocytopenia (type I, occurring within the first few days, typically benign) and severe immune-mediated HIT (type II, typically occurring between days 5 and 21) have been reported.
• Mechanical prosthetic heart valves: The use of enoxaparin for thromboprophylaxis in patients with mechanical prosthetic heart valves has not been adequately studied and is not generally recommended. Cases of prosthetic valve thrombosis, including fatal outcomes, have been reported in pregnant women with mechanical heart valves receiving enoxaparin.
• Hyperkalaemia: Heparins, including enoxaparin, can suppress adrenal secretion of aldosterone, potentially leading to hyperkalaemia, particularly in patients with diabetes mellitus, chronic renal failure, pre-existing metabolic acidosis, or those taking potassium-sparing drugs. Serum potassium should be monitored in at-risk patients.

Pregnancy and Breastfeeding

Enoxaparin does not cross the placenta and is considered one of the preferred anticoagulants when anticoagulation is necessary during pregnancy. Large observational studies and systematic reviews have not demonstrated an increased risk of congenital malformations, miscarriage, or fetal toxicity with enoxaparin use during pregnancy. However, all anticoagulant therapy during pregnancy carries an inherent risk of bleeding, and treatment decisions should be made on a case-by-case basis by a physician experienced in managing anticoagulation during pregnancy.

Multi-dose vials of enoxaparin that contain benzyl alcohol as a preservative must not be used in pregnant women, as benzyl alcohol may cross the placenta and has been associated with neonatal toxicity (gasping syndrome). Only preservative-free, single-dose formulations should be used.

Regarding breastfeeding, available data suggest that only minimal amounts of enoxaparin anti-Xa activity are detectable in breast milk. The oral bioavailability of enoxaparin is negligible, meaning that even if small amounts are ingested by a nursing infant, they would not be absorbed from the gastrointestinal tract. Breastfeeding is generally considered acceptable during enoxaparin therapy, though the decision should be discussed with a healthcare provider.

How Does Inhixa Interact with Other Drugs?

Drug interactions with enoxaparin primarily involve medications that affect haemostasis. When enoxaparin is used concurrently with other agents that impair blood clotting, the combined effect can significantly increase the risk and severity of bleeding complications. Healthcare providers must carefully evaluate the risk-benefit ratio when prescribing enoxaparin alongside any of the following medications.

Major Interactions

The following drug interactions are considered clinically significant and may require dose adjustment, additional monitoring, or avoidance of concurrent use:

Minor Interactions

The following interactions are generally less clinically significant but should still be noted and monitored:

• Dextran: May enhance the anticoagulant effect of enoxaparin. Concurrent use should be approached with caution, particularly during surgical procedures where dextran is used as a volume expander.
• Systemic corticosteroids: High-dose or prolonged corticosteroid therapy may increase the risk of gastrointestinal bleeding when combined with enoxaparin. Monitor for signs of GI bleeding.
• Potassium-sparing diuretics (spironolactone, amiloride): Because heparins can suppress aldosterone secretion, concurrent use with potassium-sparing agents may increase the risk of hyperkalaemia. Monitor serum potassium levels.
• ACE inhibitors and angiotensin receptor blockers: May contribute to hyperkalaemia when combined with heparins. Potassium monitoring is recommended, especially in patients with renal impairment.
• Selective serotonin reuptake inhibitors (SSRIs): SSRIs may impair platelet function and may slightly increase bleeding risk when combined with anticoagulants. Clinical significance is generally modest, but awareness is appropriate.

What Is the Correct Dosage of Inhixa?

Inhixa dosing varies significantly depending on the clinical indication, the patient's renal function, body weight, and age. It is essential that dosing is determined by a healthcare provider experienced in anticoagulant therapy. The following dosing guidelines are based on the approved Summary of Product Characteristics (SmPC) and international clinical guidelines.

Adults

Children

The safety and efficacy of enoxaparin in children under 18 years of age have not been fully established in all indications. However, enoxaparin is used in paediatric practice based on clinical experience and published guidelines. Paediatric dosing is weight-based and typically requires anti-Xa monitoring to ensure appropriate therapeutic levels, as the pharmacokinetics of enoxaparin differ in children compared to adults. Neonates and infants generally require higher weight-adjusted doses due to a larger volume of distribution.

Elderly

Elderly patients (aged 75 years and older) are at increased risk of bleeding with enoxaparin therapy due to age-related decline in renal function, even when serum creatinine levels appear normal. Creatinine clearance should be calculated using the Cockcroft-Gault formula (or similar) before initiating treatment. No specific dose adjustment is required for elderly patients with normal renal function at prophylactic doses, but close clinical monitoring is recommended. For the treatment of acute STEMI in patients aged 75 years and older, the initial IV bolus is omitted, and the subcutaneous dose is reduced to 75 IU/kg (0.75 mg/kg) every 12 hours (maximum 7,500 IU/75 mg per dose for the first two doses).

Renal Impairment Dose Adjustments

Missed Dose

If you miss a dose of Inhixa, take it as soon as you remember. If it is almost time for your next scheduled dose, skip the missed dose and continue with your regular dosing schedule. Never inject a double dose to make up for a missed one. If you are uncertain about what to do after missing a dose, contact your healthcare provider or pharmacist for advice, as gaps in anticoagulation can increase the risk of blood clot formation.

Overdose

Overdose of enoxaparin can lead to haemorrhagic complications ranging from minor bleeding (such as nosebleeds, bruising, or blood in urine) to severe, potentially life-threatening haemorrhage. The anticoagulant effect of enoxaparin can be partially neutralized by the slow intravenous injection of protamine sulfate. However, protamine only partially reverses the anti-Xa activity of enoxaparin (approximately 60% neutralization), unlike its near-complete reversal of unfractionated heparin. The recommended dose of protamine is 1 mg per 100 IU (1 mg) of enoxaparin administered, given within 8 hours of the enoxaparin dose. A second infusion of 0.5 mg protamine per 100 IU of enoxaparin may be given if bleeding continues. In all cases of suspected overdose, seek emergency medical attention immediately.

What Are the Side Effects of Inhixa?

Like all medicines, Inhixa can cause side effects, although not everybody experiences them. The following frequency categories are defined according to the standard convention used in medicine: very common (affects more than 1 in 10 patients), common (1 in 10 to 1 in 100), uncommon (1 in 100 to 1 in 1,000), rare (less than 1 in 1,000), and not known (cannot be estimated from available data). The side effect profile of enoxaparin has been extensively characterised through decades of clinical trials and post-marketing surveillance.

Bleeding is the most important adverse effect of enoxaparin therapy. The risk and severity of bleeding depends on the dose, duration of therapy, concurrent use of other haemostasis-affecting drugs, the patient's underlying condition, and the specific clinical indication. In large clinical trials, major bleeding events (defined as clinically overt bleeding associated with a fall in haemoglobin of at least 2 g/dL, requiring transfusion of 2 or more units of blood, or occurring in a critical site such as intracranial, retroperitoneal, or intraocular) occurred in approximately 1–4% of patients receiving therapeutic doses and less than 1% of patients receiving prophylactic doses.

Injection site reactions, including pain, bruising, and haematoma formation, are very common and are generally mild and self-limiting. The incidence of injection site haematoma can be minimized by correct injection technique, including maintaining the skin fold during injection, not rubbing the injection site afterward, and alternating injection sites between the left and right abdominal wall.

Elevated hepatic transaminases (AST and ALT) are very commonly observed during enoxaparin therapy, affecting up to 6–8% of patients in clinical trials. These elevations are typically transient, asymptomatic, and mild to moderate in degree (less than 3 times the upper limit of normal). They usually resolve spontaneously without requiring discontinuation of therapy. However, liver function tests should be performed if clinically indicated, and significant elevations should be investigated.

How Should You Store Inhixa?

Proper storage of Inhixa is essential to ensure the medication retains its full potency and safety. Enoxaparin sodium is a biological product, and exposure to inappropriate storage conditions can affect its anticoagulant activity and safety profile.

• Temperature: Store below 25°C (77°F). Do not refrigerate or freeze. Freezing can damage the pre-filled syringe and alter the product's characteristics. If accidentally frozen, the product should be discarded and not used.
• Light protection: Keep the pre-filled syringes in the original outer carton to protect from light. Light exposure can degrade the active substance over time.
• Expiry date: Do not use Inhixa after the expiry date stated on the carton and syringe label. The expiry date refers to the last day of that month.
• Multi-dose vials: The 30,000 IU (300 mg)/3 mL multi-dose vial, after first opening, may be stored for up to 28 days at below 25°C. Record the date of first use on the vial label. Discard any remaining solution after 28 days.
• Visual inspection: Before use, visually inspect the solution. Inhixa solution should be clear, colourless to pale yellow. Do not use if the solution is discoloured, cloudy, or contains particles.
• Child safety: Keep all medicines out of the sight and reach of children.
• Disposal: Do not dispose of used syringes in household waste. Used syringes and needles should be placed immediately in an appropriate sharps disposal container and returned to a pharmacy or healthcare facility for safe disposal.

What Does Inhixa Contain?

Understanding the composition of Inhixa is important for identifying potential allergens and understanding the product's characteristics.

Active substance: Enoxaparin sodium. The amount varies by presentation: pre-filled syringes are available in strengths of 2,000 IU (20 mg) / 0.2 mL, 4,000 IU (40 mg) / 0.4 mL, 6,000 IU (60 mg) / 0.6 mL, 8,000 IU (80 mg) / 0.8 mL, and 10,000 IU (100 mg) / 1 mL. The multi-dose vial contains 30,000 IU (300 mg) / 3 mL (equivalent to 10,000 IU/100 mg per mL).

Excipients (inactive ingredients):

• Water for injections: Present in all formulations as the solvent.
• Benzyl alcohol: Present only in the multi-dose 30,000 IU (300 mg)/3 mL vial as a preservative (15 mg per mL). This formulation must not be used in neonates, premature infants, or pregnant women due to the risk of benzyl alcohol toxicity.

Origin of active substance: Enoxaparin sodium is a biological product derived from the intestinal mucosa of pigs (porcine origin). The heparin is extracted, purified, and then chemically depolymerized through alkaline degradation of the benzyl ester to produce the low-molecular-weight heparin. Patients with religious or ethical concerns regarding pork-derived products, or those with pork allergies, should be informed of this origin and discuss alternatives with their healthcare provider.

Physical characteristics: Inhixa is a clear, colourless to pale yellow solution for injection. The pre-filled syringes are fitted with an automatic needle safety device to protect against needlestick injuries after use. The syringes are available with or without a needle guard, depending on the market.