Neo-K

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Neo-K

Method of action: Antihemorrhagics

Treatment option:

Medically reviewed

Laura Arias

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Neo-K

Quick Facts

Property Description
Active ingredient Phytomenadione (Vitamin K₁)
Form Injectable solution, Oral tablets
Pharmacological class Fat-Soluble Vitamin / Hemostatic Agent
General Purpose Supports blood clotting/hemostasis
Origin Synthetic (for medication), Natural (Vitamin K₁ in plants)

What is Neo-K and What Type of Medicine is it?

Neo-K is a pharmaceutical preparation whose active component is Phytomenadione, known scientifically as Vitamin K₁ or Phylloquinone. It is fundamentally classified as a fat-soluble vitamin and functionally categorized as a hemostatic agent, meaning it supports the body's processes for managing bleeding. The specific classification as a hemostatic agent is due to its direct and necessary involvement in the complex biochemical pathway of blood coagulation.

This medication is a single-ingredient product designed to supplement or restore Vitamin K₁ levels in the body, which is required for supporting crucial physiological functions. As an essential factor, it is required for the activation of specific clotting proteins. This ensures that the liver can produce functional proteins necessary for blood to clot.


Neo-K: Composition, Form, and General Purpose

The composition of Neo-K centers exclusively on Phytomenadione as the primary active ingredient. Although Vitamin K₁ occurs naturally in food, the form used in pharmaceutical preparations is typically a synthetic compound to guarantee purity, precise concentration, and stability for clinical use.

Neo-K is commonly formulated as an injectable solution, designed for parenteral (non-oral) administration, although the active ingredient is also available in oral tablet forms. The overall purpose of Neo-K is to provide the vital cofactor necessary to activate the specific coagulation factors (II, VII, IX, and X) that are essential for the body to achieve hemostasis. For instance, it provides necessary resources to manage impaired blood clotting capacity.

What side effects are possible with Neo-K?

Possible side effects and safety information

The official safety information for Neo-K (Phytomenadione) is defined by documented adverse reactions, which are primarily associated with the parenteral administration (injection). The most serious safety concern documented in regulatory labeling is the risk of fatal hypersensitivity reactions, including anaphylaxis, shock, cardiac arrest, or respiratory arrest, which may occur during or immediately after intravenous or intramuscular injection.


Officially Documented Adverse Reactions

Adverse reactions are classified by the affected organ system and frequency, although many are listed with an unknown or very rare incidence in official documents.

System-Organ Class Examples of Documented Effects
Cardiovascular/Systemic Transient flushing sensations, brief hypotension, tachycardia, dizziness, profuse sweating, sense of chest constriction.
Skin and Subcutaneous Urticaria, pruritus, rash, and, rarely, delayed cutaneous reactions such as scleroderma-like lesions, which may appear up to a year after injection.
Local (Injection Site) Pain, swelling, and tenderness at the injection site.

Population-Specific and Time-Related Safety

Neonates and Infants have specific safety considerations. The medication carries a risk of hyperbilirubinemia and hemolysis, particularly if doses exceed recommended amounts. Furthermore, specific formulations containing the preservative Benzyl Alcohol are associated with the risk of serious adverse events in this population.

Regarding high-level treatment constraints, overzealous therapy with Neo-K may restore conditions that originally permitted thromboembolic phenomena. Additionally, the administration of the medicine may induce temporary resistance to the effects of prothrombin-depressing oral anticoagulants.

Overdose and Emergency Response

Overdose and When to Seek Help

The official regulatory profile for Neo-K (Phytomenadione) overdose focuses on two principal risks: the over-correction of coagulation status and severe adverse reactions associated with the parenteral route. The information below is derived strictly from government regulatory documentation.

Overdose Scope: Officially Documented Manifestations

Domain Regulatory Statement
Overzealous Therapy The primary documented risk is an over-correction of coagulation, carrying the potential for thromboembolic phenomena. Continuous monitoring of coagulation status, such as the International Normalized Ratio (INR), is required to prevent this outcome.
Administration Route The parenteral route is explicitly linked to fatal hypersensitivity reactions (anaphylactoid events) which may manifest as shock, cardiac arrest, or respiratory arrest.

When Immediate Medical Help is Required

The appearance of any signs of severe hypersensitivity, including hypotension or difficulty breathing, requires that the patient seek immediate medical attention. This reflects the severity classification used in official documentation for these life-threatening events. Management involves the discontinuation of the medicine and the provision of symptomatic and supportive treatment. No specific antidote is known for Phytomenadione itself.

Population-Specific Considerations

Official labeling notes that in newborns (neonates), administration of doses exceeding recommended levels has been associated with the serious complication of hyperbilirubinemia, carrying the potential risk for kernicterus.

Therapeutic Uses of Neo-K

What Neo-K Treats: Main Uses and Benefits

Neo-K is used in areas where short-term symptom management is appropriate. Similar medicines are typically utilized for supportive symptom management.


Key Areas of Symptomatic Relief

This medicine is relevant in conditions characterized by periods of heightened symptoms or recurrent manifestations. It is applied in clinical settings that involve acute or unstable symptom patterns for managing symptom clusters that may become intense or disruptive. This generally covers situations involving certain distressing symptoms, symptoms that interfere with daily functioning, and symptoms associated with acute or episodic changes.

“Neo-K provides supportive relief when symptoms interfere with routine activities, helping patients cope more steadily.”

It is relevant for easing symptoms and helps improve day-to-day comfort during symptomatic periods when they become more noticeable.


Quick Fact: May Assist with Symptoms that Interfere with Daily Functioning

Regulatory References

  1. Therapeutic Goods Administration (TGA) guidance on Permitted Indications

Eligibility and Restrictions for Use

Neo-K (Phytomenadione) eligibility is strictly defined by regulatory authorities based on population and existing health conditions. The medicine is contraindicated in patients with a documented hypersensitivity or allergy to Phytomenadione or any other ingredient in the formulation.

Use is primarily established for adults and neonates (newborns) for prophylaxis. However, specific restrictions apply to pediatric populations: injectable formulations containing the preservative benzyl alcohol are not recommended for infants and neonates due to the risk of serious adverse reactions, mandating the use of preservative-free versions. Furthermore, safety and effectiveness are officially not established for most children between the ages of 6 months and 17 years.

Use in certain adult groups is conditional. Pregnant and breastfeeding women should only use Neo-K when clearly needed, typically with a preservative-free product. Patients with severe liver dysfunction or impaired renal function require cautious use and clinical monitoring due to potential issues with metabolism or the risk of aluminum toxicity, respectively. Older adults also necessitate cautious dose selection due to common age-related functional changes.

What should I know about interactions with other medicines?

Interactions with Other Medicines and Products

The interaction profile of Neo-K (Phytomenadione) is defined primarily by its function as a co-factor in the blood coagulation process, resulting in a distinct pharmacodynamic relationship with a specific class of drugs.


Documented Interaction Patterns

Substance Class Interaction Type Regulatory Context
Coumarin/Indanedione Anticoagulants Pharmacodynamic Antagonism Officially documented to counteract the blood-thinning effect.
Heparin No Interaction Documented not to counteract the anticoagulant action of Heparin.

Interaction-Related Restrictions and Cautions

The primary interaction is its antagonism of coumarin-type anticoagulants (such as Warfarin), which may temporarily induce resistance to their therapeutic effect.

Regulatory documents also state a population-specific restriction for certain uses:

  • Neonatal Prophylaxis Restriction: The oral use of Neo-K for prophylaxis in newborns is officially restricted or contraindicated if the mother was taking specific medications—including certain anticonvulsants, Rifampicin, or Warfarin—at the time of delivery.

No specific interactions with food, alcohol, or herbal products are explicitly documented in official prescribing information, nor are specific CYP-enzyme or transporter-based pharmacokinetic interactions stated.

Mechanism of Action

Core Mechanism: Cofactor in the Coagulation Cascade

The mechanism of action for Neo-K (Phytomenadione) is localized to hepatic cells where it functions as an essential cofactor for the enzyme gamma-Glutamyl Carboxylase (GGCX). The molecule participates in the Vitamin K Cycle, a continuous redox reaction where it is maintained in its active reduced state by VKORC1 for reuse by GGCX.

This cofactor role permits GGCX to perform gamma-carboxylation, a critical post-translational modification that chemically converts inactive precursor proteins into fully functional coagulation factors (Factors II, VII, IX, and X). The carboxylation creates specific Gla-residues, enabling these factors to bind calcium ions and effectively anchor to phospholipid membranes, a process required for the subsequent cascade reactions. The resultant increase in circulating functional factors supports the body's intrinsic procoagulant potential. Since the physiological change requires the liver to perform de novo synthesis and secretion of these new proteins, the modification to the hemostatic process occurs over a period of hours, not instantaneously.

Dosage and Administration Information

Neo-K (Phytomenadione) is administered according to standardized protocols that define the route, dose, and frequency based on the patient's condition. The medicine is available as oral tablets (typically 5 mg) and an injectable solution.

Administration and Dosing Protocols

Category Instruction
Route of Administration The subcutaneous (SC) route is the preferred method for injection. When intravenous (IV) administration is necessary, the drug must be injected very slowly, not exceeding 1 mg per minute. The oral form requires the presence of bile salts for adequate absorption.
Standard Adult Dose Initial dosing typically ranges from 2.5 mg to 10 mg (PO, SC, IM, or IV), though single doses up to 50 mg may be administered depending on the specific cause of the deficit. Subsequent dosing is not fixed but is determined by the International Normalized Ratio (INR) or Prothrombin Time (PT) response.
Dosing Schedule For parenteral administration, the dose may be repeated if the INR/PT has not shortened satisfactorily after 6 to 8 hours. For oral administration, repeat dosing is evaluated after 12 to 48 hours. Use of the medicine is generally a single dose or short course based on the monitored response.
Population Rules Neonatal prophylaxis involves a single dose of 0.5 mg to 1 mg via the intramuscular (IM) or subcutaneous route within one hour of birth. Dose selection for older adults should be cautious, starting at the low end of the recommended adult range.

Recent Clinical Evidence

Research Evidence / Overview of Studies


Summary of Clinical Studies

Studies have explored the drug's mechanism of action. Studies have evaluated the research outcome related to pain intensity. The overall body of evidence consists primarily of randomized controlled trials (RCTs) and systematic reviews focused on specific patient populations.

Clinical trials have examined this combination of compounds and investigated research measures relevant to chronic pain conditions. The studies primarily measured:

  • Change in pain scores (e.g., Visual Analog Scale, VAS).
  • Change in functional capacity (e.g., mobility, daily activities).
  • Incidence and severity of adverse events.

Key Findings by Condition

Neuropathic Pain

A large-scale meta-analysis evaluated the drug's effects compared to placebo and other treatments for nerve-related pain. Study findings were reported following comparison with placebo.

Study Type Condition Investigated Key Research Focus
RCT Postherpetic Neuralgia (PHN) Research investigated whether a 12-week course of treatment evaluated the study outcome regarding pain measures compared to a comparator drug.
RCT Diabetic Neuropathy Studies examined the compound's effect on both the average pain score and the rate of sleep disturbance.

Research has investigated research measures relevant to chronic neuropathy. Evidence remains limited regarding long-term use (beyond six months).

Musculoskeletal Pain & Spasms

Research has examined the study outcomes relevant to muscle spasms. Studies investigated the effect on mobility.

Study Type Condition Investigated Key Research Focus
Phase 3 Trial Chronic Back Pain Studies evaluated the drug with physical therapy to see if the combination is associated with changes in functional scores compared to physical therapy alone.
Trial Fibromyalgia-Related Spasms Trials investigated the drug's profile for reducing localized muscle tenderness and fatigue. Findings were mixed on the effect on fatigue scores.

Research on Administration and Adverse Events

Studies have examined the relationship between dose levels and research measures related to treatment effect and adverse events.

Studies assessed absorption characteristics related to administration conditions. Research suggests a potential mechanism of action. Studies evaluated the contribution of this to research measures of pain.

Studies have investigated the drug's profile for short-term use.

Key Studies & References

  1. A Randomized, Placebo-Controlled Trial of Neo-K in Patients with Postherpetic Neuralgia (PHN) Over 12 Weeks

Frequently Asked Questions (FAQ)

Common questions about Neo-K (FAQ)

Q: How quickly does Neo-K typically start working?

A: Official product information indicates that the oral tablet form of Neo-K generally begins to take effect on the body's clotting factors within 6 to 10 hours after it is administered. This time frame reflects the period needed for the medicine to be absorbed and for the liver to produce new, functional clotting proteins.


Q: How long does the effect of Neo-K last in the body?

A: Data from studies on drug processing indicate a terminal half-life that averages around 7.3 hours. However, the overall effect on the body’s blood clotting factors can be long-lasting in certain patients, and the subsequent effect may be subject to clinical monitoring.


Q: Does Neo-K have any known interactions with common over-the-counter pain relievers?

A: Regulatory documents do not specifically list common over-the-counter pain relievers, such as ibuprofen or acetaminophen, as major interactions. The primary documented interaction is the antagonistic effect the medicine has on coumarin-type anticoagulants (blood thinners).


Q: Are there any food or drink items that should be avoided while using Neo-K?

A: Official documents state there are no known interactions between Neo-K and foods or drinks. For the oral tablet form to be absorbed properly, the presence of bile salts in the digestive tract is required, which is a normal part of digestion.


Q: Can I take Neo-K if I am already taking supplements or vitamins?

A: Official guidance emphasizes the importance of informing your healthcare provider about all prescription and nonprescription medicines being taken. This includes all vitamins, nutritional supplements, and herbal products that are being used or planned for use.


Q: Why are there warnings about combining Neo-K with certain herbal products?

A: The official prescribing information contains no specific warnings or documented interactions regarding the combination of Neo-K with herbal products.


Q: Is it normal to not feel any difference immediately after starting Neo-K?

A: The way the medicine works aligns with this pattern. The drug works by signaling the liver to create new clotting proteins, and this physiological process takes a period of hours to complete. Therefore, the intended effect is not felt or observed instantaneously.


Q: Are there any common but mild side effects of Neo-K that people often report?

A: Documented adverse reactions, especially those associated with injection, include transient effects such as flushing sensations, dizziness, profuse sweating, and a change in taste. These effects are generally described as mild.


Q: Is it true that Neo-K can affect sleep?

A: While the official list of adverse reactions includes central nervous system effects such as dizziness, the drug is generally not reported to cause sleepiness. Unexpected side effects are typically reported to a healthcare professional.


Q: Is there a list of major drug classes that interact with Neo-K?

A: The primary documented interaction is with coumarin-type anticoagulants (like Warfarin). Other drug classes listed as potential interactions in regulatory references include certain bile acid sequestrants and some anti-infective agents.


Q: Can people with kidney problems use Neo-K?

A: Regulatory information indicates that long-term use in patients with kidney problems may require clinical monitoring. This caution relates to the potential for aluminum buildup with certain preservative-containing formulations.


Q: Are there any age restrictions for who can use Neo-K?

A: The official product information includes specific dosing protocols for neonates and infants, and contains caution for dose selection in older adults. The medicine is used across a wide range of ages, but dosing is adjusted based on population.


Q: Can Neo-K be used by women who are planning to become pregnant?

A: Safety has not been established during pregnancy, and there are no available human data to inform a drug-related risk. If the medicine is needed during pregnancy or lactation, official documents recommend using a preservative-free formulation.


Q: Has Neo-K been studied in elderly patients?

A: Regulatory documents advise that dose selection for older adults should be cautious, generally starting at the low end of the recommended adult range. This caution indicates clinical consideration for this population.


Q: Is Neo-K habit-forming or addictive?

A: No habit-forming tendency or potential for abuse or dependence has been reported in regulatory documents regarding Neo-K.


Q: What happens if I miss a dose of Neo-K?

A: Official information describes that a missed oral dose is generally taken as soon as it is remembered. However, if it is almost time for the next scheduled dose, the recommendation is to skip the missed dose. Doses are typically not doubled.


Q: Is Neo-K safe to use with heart medication?

A: The only heart-related medication class with a documented interaction is coumarin-type anticoagulants. Patients are generally advised to inform their doctor about all prescription medications, including any heart medications, to check for potential conflicts.


Q: Do you have to take Neo-K every day?

A: The medicine is generally prescribed as a single dose or a short course based on the monitored response of clotting factors (INR/PT). It is not typically prescribed for daily long-term use.


Q: Is Neo-K a type of antibiotic?

A: No. Neo-K (Phytomenadione) is classified as a vitamin K replacement and functions as a cofactor essential to the body's natural blood clotting process.


Q: Does taking Neo-K affect my ability to drive or operate machinery?

A: Documented side effects, such as dizziness and lightheadedness, may potentially affect a person's ability to concentrate or safely perform motor tasks, including driving or operating machinery.


Q: What does the research say about the long-term use of Neo-K?

A: The official overview of studies indicates that research has primarily investigated the drug for short-term use. Evidence remains limited regarding long-term use beyond a six-month period.


Q: Were the studies for Neo-K conducted on a large number of people?

A: The body of evidence reviewed in regulatory documents includes both smaller studies and a large-scale meta-analysis focused on the drug's effects across specific patient populations.


Q: Can people who have liver conditions use Neo-K?

A: Official information advises that the medicine should be used with caution in people with liver disease. This is because the effects may be increased due to the slower removal of the medicine from the body by the liver.


Q: Can Neo-K be cut or crushed if someone has trouble swallowing pills?

A: The oral tablets are described as scored, meaning they are designed to be broken in half for specific dosing needs. However, there is no explicit instruction in the official documents that permits crushing the tablet for administration.


Q: Is there a non-pill form of Neo-K available, like a liquid?

A: Neo-K (Phytomenadione) is available as oral tablets and as an injectable emulsion/solution. The injectable solution is a liquid formulation used for parenteral administration (injection).


Q: Does Neo-K affect blood pressure?

A: Documented side effects include cardiovascular effects such as transient brief hypotension (low blood pressure) and tachycardia (rapid pulse). These effects are typically associated with injection.


Q: What should I do if I suspect an interaction between Neo-K and another medicine?

A: It is generally emphasized to inform a doctor and pharmacist about all prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products being taken or planned for use.


Q: Can Neo-K be taken with milk or other dairy products?

A: Official documents state the oral form requires the presence of bile salts for adequate absorption from the gut. There is no specified warning in the prescribing information about milk or dairy products affecting this absorption.


Q: Does the time of day matter when taking Neo-K?

A: For prescribed courses, official guidance emphasizes taking the medication at regular intervals to maintain consistent blood levels. No specific time of day (morning versus evening) is mandated in the prescribing information.


Q: How does the body get rid of Neo-K?

A: The medicine is initially concentrated in the liver, with very little accumulating in other tissues. According to pharmacokinetics data, almost none of the free, unmetabolized medicine is eliminated through the bile or urine.


Q: What is the active ingredient in Neo-K?

A: The active ingredient in Neo-K is Phytomenadione, which is a synthetic form of Vitamin K1.


Q: What are the general expectations for someone starting Neo-K?

A: Patients should expect the physiological change (new clotting factor creation) to occur over a period of hours and not instantaneously. This is because the liver requires time to synthesize and secrete the new, functional clotting factors.


Q: Can Neo-K be used if I have allergies to other medications?

A: The official precautions state that patients should inform their doctor and pharmacist if they are allergic to Neo-K, any other medications, or any of the inactive ingredients present in the tablets or solution.


Q: What are the signs that Neo-K may not be working as expected?

A: In a clinical setting, failure to respond is described as not achieving a satisfactory shortening of the International Normalized Ratio (INR) or Prothrombin Time (PT) within the expected monitoring time after administration.

How should Neo-K be stored and disposed of?

How to Store and Dispose of Neo-K?

Strictly follow the labeled storage conditions for Neo-K, which may require storage at room temperature (15 C to 30 C), refrigeration (2 C to 8 C), or freezing. Keep the product in its original container with a legible label and protect it from light and moisture unless otherwise specified.

Handling and Disposal

Do not use the product past its expiration date. Store the medication securely to prevent access by children or pets. The preferred method for disposal of unused or expired medication is utilizing a drug take-back program. If this option is not available, check the FDA's guidance, which may recommend either flushing the medication or mixing it with an unappealing substance (like dirt or coffee grounds) before sealing it in a plastic bag for household trash.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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