Granix

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Medically reviewed

Marina Burgos

Last updated on 10/01/2026

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 Granix

Quick Facts

Property Description
Active ingredient Filgrastim (Tbo-filgrastim)
Form Solution for injection
Pharmacological class Hematopoietic agent, Colony-Stimulating Factor (CSF)
General purpose Supports the immune system
Origin Recombinant biological product

What Type of Medicine is Granix (Filgrastim)?

Granix is a medicine classified as a Hematopoietic agent, which is a pharmacological class used to influence the body’s blood cell formation processes. The active ingredient is Filgrastim, which belongs to the specific category of colony-stimulating factors (CSFs). Unlike older, non-biologic medications, Granix is a recombinant biological product, synthesized using advanced biotechnology to precisely replicate the structure of the human protein granulocyte colony-stimulating factor (G-CSF). This specific origin ensures high target specificity, a key feature supported by pharmacological studies.

Composition and Delivery Form

The preparation is distinct as it uses a specific formulation of the protein known as Tbo-filgrastim, which is the sole active component. Structurally, this is a non-glycosylated protein analogue. Granix is supplied as a sterile, clear, preservative-free solution for injection in a single-dose prefilled syringe. This liquid formulation is administered via the subcutaneous injection route or through intravenous infusion. The use of prefilled syringes is a differentiating factor, often employed in clinical settings for consistency and ease of delivery.

General Purpose: Supporting Immune Function

The general purpose of Granix is to rapidly enhance the body’s defenses by increasing the supply of crucial immune cells. The medicine acts by signaling the bone marrow to accelerate the production, maturation, and release of neutrophils, which are the primary type of white blood cell responsible for fighting infections. This targeted stimulation is typically employed to address neutropenia—a critically low neutrophil count. Clinical analysis of the agent confirms its utility in preventing severe neutrophil reduction. By boosting the body's capacity to produce these cells, Granix supports the overall immune system and reinforces the patient’s natural defenses.

Regulatory References

  1. MedlinePlus Drug Information, Filgrastim

What side effects are possible with Granix?

Possible Side Effects and Safety Information

The official safety profile for Granix (Tbo-filgrastim) is categorized by frequency and the body system affected, based on observations from clinical trials and post-marketing experience. Adverse reactions are classified according to regulatory standards.


Frequency Classification and Affected Systems

Classification Representative Side Effects Affected System-Organ Classes
Most Common Bone pain Musculoskeletal/Connective Tissue
Common Diarrhea, Extremity pain, Anti-drug antibodies Gastrointestinal, Musculoskeletal, Immune System
Very Common Thrombocytopenia (in pediatric patients) Hematologic

Bone pain is designated as the most common adverse reaction observed in patients receiving this medicine. Other frequently documented reactions include general disorders such as fever and fatigue.


Serious Adverse Reactions and Constraints

The regulatory label includes specific warnings for rare, but serious, adverse reactions. These include Splenic rupture (including fatal cases), Acute Respiratory Distress Syndrome (ARDS), Capillary Leak Syndrome (CLS), and Glomerulonephritis (a form of kidney injury). Serious Allergic Reactions, including anaphylaxis, are also noted and can occur upon initial exposure.

Safety considerations apply to specific populations. Patients with Sickle Cell Disease carry a risk of severe or fatal sickle cell crises. The potential for Myelodysplastic Syndrome (MDS) or Acute Myeloid Leukemia (AML) is noted for patients with Severe Chronic Neutropenia and certain cancer patients receiving chemotherapy or radiotherapy. The medicine is formally contraindicated in individuals with a history of serious allergic reactions to filgrastim products.

Overdose and Emergency Response

Overdose and when to seek help

The official regulatory profile for Granix (Tbo-filgrastim) overdose focuses strictly on the consequences of excessive biological stimulation. An overdose is documented as an exaggeration of the medicine’s primary effect on the hematopoietic system, resulting in excessive leukocytosis and high neutrophil counts. This specific manifestation is typically identified by a significant overproduction of white blood cells, with counts of 100,000/mm³ or greater being noted in cases of overexposure, confirming the state of pharmacological over-stimulation.


Emergency Response and Management

Immediate medical attention must be sought if an overdose is suspected or if current laboratory results indicate the critical threshold of excessive leukocytosis. The primary regulatory-mandated action upon confirming an overdose is the immediate discontinuation of Granix therapy.

Since no specific antidote is known for Tbo-filgrastim, management consists solely of providing symptomatic and supportive treatment. This includes the requirement for frequent monitoring of the patient’s Complete Blood Counts (CBCs) and Absolute Neutrophil Count (ANC) until the cell counts safely return to the acceptable range. No specific population-based considerations for overdose severity are explicitly documented in the official regulatory sections.

Therapeutic Uses of Granix

Granix is generally used for managing symptoms associated with significant deficiency of infection-fighting white blood cells, referred to as severe neutropenia. This medicine is commonly used to help decrease the chance of infection in people who are receiving certain chemotherapy or who have chronic immune-related disorders.

Prophylactic Management of Post-Chemotherapy Infection Risk

The medication plays a key role in managing conditions presenting with acute or recurrent episodes of immune compromise, including chemotherapy-induced neutropenia and long-term disorders such as Severe Chronic Neutropenia (like congenital, cyclic, or idiopathic forms). In clinical settings, Granix is also relevant for managing the specific scenario of stem cell collection (mobilization) before an autologous transplant.

The core benefit plays a role in managing the duration of severe neutropenia, which may assist with maintaining functional stability and supports general well-being during symptomatic phases. This supports the patient during difficult episodes and may help with managing symptoms that create noticeable physiological strain, particularly the symptoms related to high infection risk and fever.

“This supportive therapy is applied across domains where additional symptomatic support is needed to help manage periods of heightened physiological stress.”

Quick Fact: Relief for Infection Risk

Property Description
Primary Condition Severe Neutropenia (critically low white cells)
Therapeutic Context Supportive care post-chemotherapy or chronic management
Main Symptom Cluster Risk of infection, febrile episodes, recurrent illness
Patient Benefit Supports immune processes; helps ease overall symptom load

Regulatory References

  1. NIH MedlinePlus Drug Information

Eligibility and Restrictions for Use

Eligibility Profile for Granix (Tbo-filgrastim)

The criteria for using Granix are strictly defined by regulatory documents, listing populations that are eligible, restricted, or absolutely prohibited from use.


Who Cannot Use Granix (Contraindications)

Granix is absolutely contraindicated for patients who have a documented history of serious allergic reactions (hypersensitivity) to any filgrastim or pegfilgrastim product.


Restrictions and Special Considerations

Population Group Regulatory Status
Myeloid Malignancies (MDS) Not indicated for use, as the medicine may stimulate tumor growth.
Infants Use not established in children younger than 1 month of age.
Sickle Cell Disorders Must be used with extreme caution; use must be discontinued if a sickle cell crisis is suspected.
Pregnancy/Lactation Avoid breastfeeding during treatment and for two weeks after the final dose. Use during pregnancy is conditional on benefit outweighing risk.
Adults and Children Established use in adults and children 1 month and older for approved indications.
Organ Impairment Dose adjustment is not required for severe renal or hepatic impairment.

Eligibility Summary

Official documents define eligible groups as adults and children ge 1 month old, provided they do not have the contraindicating allergic history or myeloid malignancies. The label mandates specific restrictions, including avoiding use concurrent with chemotherapy and exercising caution in patients with sickle cell disorders.

What should I know about interactions with other medicines?

Official Status of Interaction Studies

The regulatory prescribing information for Granix (Tbo-filgrastim) explicitly states that no formal drug interaction studies have been performed to assess its effects when co-administered with other medicinal products. As a result, there is no documented information in official government sources regarding pharmacokinetic interactions, such as those mediated by cytochrome P450 (CYP) enzymes or drug transporters. Furthermore, no known interactions with food, drinks, or herbal products are specified in regulatory documents. This defines the scope of officially verifiable interaction data.

Pharmacodynamic Interaction Cautions

The drug’s interaction profile includes specific pharmacodynamic cautions related to its effect on white blood cell production. Co-administration with certain medicinal products that also influence neutrophil release may result in an additive effect. Specifically, caution is advised when administering Granix alongside Lithium, as this substance may potentiate the release of neutrophils. This potential interaction is noted due to the regulatory concern over an overly pronounced increase in white blood cell counts.

Mandatory Timing Restrictions

A critical, regulatory-mandated timing rule exists when Granix is used in conjunction with cytotoxic chemotherapy. Granix must not be administered during the 24-hour period immediately prior to, or the 24-hour period immediately following, the administration of cytotoxic chemotherapy. This restriction is a regulatory requirement imposed to mitigate the risk of adverse outcomes related to the sensitivity of rapidly dividing myeloid cells to cytotoxic agents.

Mechanism of Action

Molecular Activation of the G-CSF Receptor

The mechanism of Granix begins with its active ingredient, Filgrastim, acting as a direct agonist on the G-CSF Receptor located primarily on precursor cells within the bone marrow. By binding to this specific receptor, the medicine initiates intracellular signaling cascades, such as the JAK/STAT pathway, delivering a necessary stimulus to target cells. This targets the very start of the process that governs the proliferation and development of a specific white blood cell type.

Accelerating Granulopoiesis

Receptor activation triggers the acceleration of granulopoiesis, the developmental pathway for neutrophils. The mechanism promotes myeloid precursor cells to rapidly increase their proliferation and differentiation rates within the bone marrow. This critical acceleration leads to the expansion of the entire production line, generating a greater pool of mature neutrophils.

Systemic Mobilization of Neutrophils

The final stage of the mechanism involves enhanced mobilization, where the drug promotes the rapid release of this newly generated pool of mature neutrophils from the bone marrow into the peripheral blood circulation. This physiological consequence results in a systemic increase in the absolute count of circulating mature neutrophils, directly contributing to the physiological concentration of circulating immune cells.

Dosage and Administration Information

Administration Overview

Granix is administered as an injection under the skin (subcutaneously). The administration process involves preparing the medication, selecting an appropriate injection site, and following specific techniques to ensure the medication is delivered correctly.

Preparation for Use

Before administration, the medication should be inspected visually. The liquid should be clear and colorless. If the solution is discolored or contains visible particles, it should not be used. It is recommended to allow the prefilled syringe to reach room temperature before injection to improve comfort during the procedure.

Injection Site Selection

Commonly used areas for subcutaneous injection include:

  • The outer area of the upper arms
  • The abdomen (avoiding the area immediately surrounding the navel)
  • The front of the middle thighs
  • The upper outer area of the buttocks

It is important to rotate the injection site with each dose to reduce the risk of skin irritation or tissue issues at the site of injection. Avoid areas where the skin is bruised, tender, red, or hard.

Disposal of Supplies

Used syringes and needles must be disposed of in a puncture-resistant sharps container immediately after use. These materials should not be recycled or disposed of in regular household trash. Proper disposal helps prevent accidental needle sticks and ensures the safety of others in the household.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Granix

This overview describes the types of clinical research conducted on the active ingredient in Granix, Filgrastim, and what official sources report about the findings. This summary is based on evidence reviewed by regulatory bodies and scientific literature, and it does not contain any clinical advice or instructions.


Evidence for Use in Preventing Neutropenia after Chemotherapy

Research in this area has primarily involved Randomized Controlled Trials (RCTs), further analyzed in systematic reviews and meta-analyses. The populations evaluated included adults and older adults with various types of cancer who were receiving myelosuppressive chemotherapy. Researchers monitored key metrics like the duration of severe neutropenia (DSN) and the occurrence of febrile neutropenia (FN). Studies reported patterns related to a shorter ANC recovery time following chemotherapy cycles and also examined the frequency of infection-related fever and associated hospitalization rates. What remains uncertain is the long-term functional outcomes directly attributable only to the management of acute neutropenia itself, separate from the underlying cancer treatment.


Evidence for Use in Severe Chronic Neutropenia (SCN)

For managing long-term conditions like Severe Chronic Neutropenia (SCN), the evidence landscape includes initial clinical trials followed by long-term observational studies and national registries. The populations studied include both pediatric and adult patients. Studies consistently evaluated the Absolute Neutrophil Count (ANC) above a critical baseline level. Observations reported patterns related to a lower overall rate and severity of bacterial infections in patient groups where stable neutrophil counts were maintained over extended follow-up periods. Research regarding the long-term impact on the bone marrow microenvironment itself is not fully established.


What Research Gaps and Uncertainty Remain

Regulatory and scientific reviews highlight several areas where data are still emerging: Follow-up durations were limited in many of the trials for the chemotherapy-related indication, focusing mainly on the acute period of treatment. The evidence is limited when attempting to generalize findings to all possible new or non-standard chemotherapy regimens. Data for special groups, such as pregnancy, remain insufficient. Long-term data remain limited for all indications outside of the SCN registry.

Key Studies & References Efficacy and Safety of Filgrastim and Its Biosimilars to Prevent Febrile Neutropenia in Cancer Patients: A Prospective Study and Meta-Analysis

Frequently Asked Questions (FAQ)

Common questions about Granix (FAQ)


Q: Are there any common foods or drinks that should be avoided while taking Granix?

Regulatory documents state that no formal drug interaction studies have been conducted to assess effects with food, drinks, or herbal products. Therefore, official product information does not specify any common foods or drinks that must be avoided.


Q: Is it possible for Granix to cause weight changes?

Official adverse reaction tables from clinical trials do not list weight change among the most frequently reported side effects. However, regulatory warnings note a rare, serious condition called Capillary Leak Syndrome, which can cause fluid retention and swelling, or edema.


Q: Is a headache a common side effect reported with Granix?

According to official product information, headache is a documented common adverse reaction reported in pediatric patients. In adult studies, headache is not consistently listed as one of the most common adverse reactions, which is bone pain.


Q: Is it normal to feel a bit tired when first starting Granix?

Fatigue is one of the documented general disorders associated with the use of Granix, according to regulatory information. However, official documents do not specifically address whether this feeling is more frequent or intense during the initial days of treatment.


Q: Are there known interactions between Granix and herbal remedies?

Official regulatory documents explicitly state that no formal drug interaction studies have been conducted to assess effects with herbal products. As a result, no specific interactions with herbal remedies are defined in the product information.


Q: Why is it important to tell the doctor about all other medicines before starting Granix?

It is important to provide a complete list of current medicines because a specific caution is noted for co-administration with products like Lithium. This combination may potentiate the release of neutrophils, potentially causing an overly pronounced increase in white blood cell counts.


Q: Why is Granix sometimes started at a low amount and then increased?

The initial dose of Granix is calculated based on the patient's body weight. The daily administration is designed to continue until the treating physician determines the patient's blood cell count has recovered to an appropriate level. The duration of the regimen is determined by the patient's response.


Q: Are there any specific times of the day recommended for taking Granix?

Granix is administered on a once-daily schedule. While official documents do not mandate a specific time of day (morning or evening), use at approximately the same time each day is consistent with a daily schedule.


Q: How quickly can I expect to notice any effects from Granix?

The medicine is absorbed rapidly, with circulating levels generally reaching a peak within 2 to 8 hours after a subcutaneous injection. The clinical effect is tracked by measuring the time required for the body to produce new white blood cells.


Q: What happens if I accidentally miss a scheduled time to take Granix?

Patient information typically advises contacting the prescribing healthcare provider or nurse for guidance on how to manage a missed dose. A healthcare provider must be contacted to determine the appropriate timing for the next dose, as individual guidance is necessary.


Q: What is the purpose of the 'inactive ingredients' listed for Granix?

Inactive ingredients, such as sorbitol and glacial acetic acid, are included in the formulation to ensure the solution remains stable and clear. These components also help maintain the correct level of acidity (pH) necessary for the injection.


Q: Is Granix generally well-tolerated?

The official safety profile provides a full list of observed adverse reactions. The most common adverse reaction reported is bone pain, which is consistent with the drug's mechanism of stimulating the bone marrow.


Q: Are there different strengths of Granix available?

Yes, official product information lists two strengths: a 300 mcg prefilled syringe and a 480 mcg prefilled syringe. The specific amount of medication administered to a patient is calculated based on their individual needs, which may not require the entire volume of a syringe.


Q: Can Granix be taken with other prescription medications for the same condition?

No formal clinical drug interaction studies have been performed for most medicinal products. Specific regulatory timing restrictions apply when Granix is used alongside cytotoxic chemotherapy treatments.


Q: What were the main positive outcomes measured in the Granix clinical trials?

According to official clinical study summaries, the primary outcomes measured were the reduction in the duration of severe neutropenia (DSN) and the reduction in the incidence of febrile neutropenia (FN). These metrics reflect the changes in blood cell counts during the period of treatment.


Q: Is it safe to drink alcohol in small amounts while taking Granix?

Official patient information indicates that any use of alcohol should be discussed with a healthcare provider. Specific instructions regarding alcohol consumption are not detailed in the official product information.


Q: Does Granix affect blood pressure?

Blood pressure changes are not listed among the most common side effects. However, regulatory warnings note a rare, serious condition called Capillary Leak Syndrome (CLS), which is characterized by symptoms that include hypotension (low blood pressure).


Q: What is the general duration of effect for a single dose of Granix?

The active substance is eliminated from the bloodstream within a few hours. The overall effect on the white blood cell count lasts longer, with circulating neutrophil counts typically returning to pre-treatment baseline levels within about four days after discontinuation of the daily medicine.


Q: Can Granix affect mental clarity or focus?

Official documents do not list changes in mental clarity or focus as a common side effect. However, severe dizziness or feeling faint are noted as potential symptoms associated with the rare, serious condition Capillary Leak Syndrome (CLS).


Q: Is it possible for Granix to lose its effect over time?

Regulatory documents state that accumulation of the drug was not observed after repeated daily dosing. This suggests that the pharmacological response remains consistent when the daily regimen is maintained.


Q: Is Granix a controlled substance?

Granix is classified as a hematopoietic agent, which is a biological product used to stimulate blood cell formation. It is not classified as a controlled substance by federal regulatory authorities.


Q: Does Granix affect sleep patterns?

Sleep pattern changes are not listed among the most common adverse reactions documented in official information. However, general disorders such as fever and fatigue are documented.


Q: Are there any specific laboratory tests that need to be done while on Granix?

Yes, official prescribing documents mandate that the patient's Complete Blood Count (CBC), including the Absolute Neutrophil Count (ANC), must be monitored. The purpose of this testing is to track the body's response to the medicine and inform the duration of the regimen.


Q: Is Granix used for other conditions besides its main approved use?

In addition to reducing the duration of severe neutropenia following chemotherapy, Granix is also approved to increase survival in patients exposed to myelosuppressive doses of radiation. These are the conditions listed in official regulatory documents for the use of the medicine.


Q: Does Granix stay in the body for a long time after the last dose?

The active substance is eliminated from the bloodstream with a relatively short elimination half-life of approximately 1.8 to 3.5 hours. However, the resulting increase in white blood cell counts can persist for a few days after the medicine is stopped.


Q: Does Granix affect the bone marrow microenvironment?

Granix is a Colony-Stimulating Factor that acts on specific receptors on bone marrow precursor cells to stimulate white blood cell growth. Regulatory warnings note the potential for Granix to act as a growth factor for certain tumor types, including myeloid malignancies.


Q: Is the dosing schedule for Granix the same for all patients?

The recommended schedule is a once-daily injection. While the schedule is consistent, the duration of treatment (the number of days) and the calculated dose (which is specific to each patient's body weight) vary based on the patient’s clinical condition and blood cell count response.


Q: What is the evidence regarding Granix and its long-term impact on overall health?

For the chemotherapy indication, clinical trials typically focus on the immediate period of treatment. Official documents highlight that the evidence regarding long-term functional outcomes directly attributable only to the management of acute neutropenia remains limited.


Q: Can Granix be taken with multivitamins or mineral supplements?

Official regulatory documents state that no formal drug interaction studies have been conducted to assess effects with other products, including multivitamins or mineral supplements.

How should Granix be stored and disposed of?

Granix must be stored in the refrigerator at a temperature between 2 C and 8 C (36 F to 46 F). To protect the medicine from light, keep the syringe in its original carton until the time of use.

Storage Requirements

  • Do not freeze Granix. It must also not be shaken.
  • The product can be stored at room temperature (23 C to 27 C) for a single period of up to 5 days; if unused after this time, the product must be discarded.
  • Prior to use, allow the syringe to warm to room temperature, and visually inspect the solution for any discoloration or particles.
  • Keep out of the reach of children.

Disposal

Granix is for single-dose use only, and any unused portion must be discarded. Used needles and syringes must be placed immediately in an FDA-approved sharps container. Do not dispose of the sharps container in household trash or recycling unless permitted by local community guidelines.

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

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