Flunisolide

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Flunisolide

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Treatment option: Asthma, Bronchospasm

Medically reviewed

Marina Burgos

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 Flunisolide

What is Flunisolide?

Flunisolide is a synthetic compound belonging to the class of medications known as corticosteroids. It is designed to mimic the effects of hormones naturally produced by the adrenal glands, which play a significant role in regulating the body's inflammatory response.

Mechanism of Action

As a corticosteroid, flunisolide works by penetrating cell membranes to bind with specific cytoplasmic receptors. This interaction influences protein synthesis and inhibits the release of various substances in the body that trigger inflammation, such as histamine, leukotrienes, and cytokines. By reducing the activity of these inflammatory mediators, the medication helps to decrease swelling, redness, and irritation in the tissues where it is applied.

Common Applications

Flunisolide is primarily utilized for its localized anti-inflammatory properties. Its applications generally fall into two main categories:

  • Respiratory Management: When used in inhaled forms, it targets the airways to help manage chronic inflammatory conditions. It assists in maintaining open passages by reducing mucosal edema and hyperreactivity in the bronchial tubes.
  • Nasal Care: In nasal spray formulations, flunisolide is used to address inflammation of the nasal lining. This is typically associated with seasonal or year-round sensitivities that cause symptoms like congestion and sneezing.

Chemical Characteristics

Flunisolide is chemically structured to be lipid-soluble, which allows it to be effectively absorbed by mucous membranes. It is engineered for high potency at the site of application while being metabolized relatively quickly once it enters the systemic circulation, a characteristic intended to focus its activity where it is most needed.

Regulatory References

  1. Flunisolide Nasal Spray: MedlinePlus Drug Information

What side effects are possible with Flunisolide?

Possible side effects and safety information

The safety profile of Flunisolide is officially characterized by documenting adverse reactions by frequency and physiological system, with specific emphasis on local and systemic effects linked to its corticosteroid class.

Common Adverse Reactions

Side effects reported with an incidence of ge 3% to >10% in clinical trials are officially classified as common. These are often related to the local site of administration and include nasal burning or stinging, epistaxis (nosebleeds), pharyngitis (sore throat), an unpleasant aftertaste, headache, and nausea or vomiting.

System-Organ Classes Involved

Official regulatory documents categorize documented adverse reactions across several system groups, including Respiratory, Thoracic & Mediastinal (e.g., hoarseness, localized Candida infection, nasal irritation) and Gastrointestinal (e.g., aftertaste, upset stomach).

Serious Adverse Reactions and Safety Constraints

Certain clinically significant events are noted in prescribing information, including the rare occurrence of nasal septal perforation and severe hypersensitivity reactions. Because Flunisolide is a glucocorticoid, there is a documented risk of HPA-axis suppression and potential signs of hypercorticism, particularly with prolonged use or dose transitions. Use is restricted in the presence of an untreated localized nasal infection.

Population-Specific Safety Notes Official Regulatory Statement
Pediatric Patients Documented potential for a reduction in growth velocity with prolonged use.
Pregnant Women Classified as Pregnancy Category C; use determined only if potential benefits outweigh risks.

Systemic effects such as glaucoma or cataracts are associated with the long-term or prolonged use of corticosteroids. Patients transferring from systemic corticosteroids must be monitored for signs of adrenal insufficiency.

Overdose and Emergency Response

Overdose and when to seek help

The officially documented profile for Flunisolide overdose centers on the risk of systemic effects resulting from the prolonged use of excessively high doses, rather than acute toxicity. Regulatory information notes that acute overdosage has not been reported.

Overexposure may lead to signs of hypercorticism, which are clinical manifestations of systemic corticosteroid excess. These can include features such as unusual weakness, weight gain, and muscle wasting. More critically, prolonged high-dose use carries the risk of Hypothalamic-Pituitary-Adrenal (HPA) axis suppression, which may result in acute adrenal insufficiency during times of physical stress.

Regulatory Mandates for Emergency Action

Action Required When to Seek Help
Seek Immediate Medical Attention or Contact a Poison Control Center Required if an overdose is suspected or if serious symptoms manifest, such as passing out or experiencing trouble breathing.
Dose Reduction Required management for chronic overexposure, involving the gradual decrease or withdrawal of the drug under medical supervision.

No specific pharmacological antidote is known for Flunisolide overdosage; management involves symptomatic and supportive treatment. Regulatory documents specify that pediatric patients require careful consideration due to their increased susceptibility to systemic effects like HPA axis suppression and the risk of growth reduction from chronic high-dose exposure.

Therapeutic Uses of Flunisolide

Quick Facts

  • May provide relief for symptoms of seasonal or year-round allergies (rhinitis), including sneezing, runny nose, and nasal congestion.
  • Utilized as prophylactic therapy for the maintenance treatment of asthma in adult and pediatric patients (6 years of age and older).
  • May support a reduction in the need for oral corticosteroids in certain asthma patients.

Flunisolide is a prescription medication utilized in managing respiratory conditions and symptoms linked to inflammation. Its primary therapeutic applications involve the maintenance treatment of chronic asthma. For individuals aged six years and older, it serves as prophylactic therapy to support the control of difficulty breathing, wheezing, and coughing associated with the condition.

The medication is also utilized to help relieve the symptoms of both seasonal (hay fever) and perennial allergic rhinitis. In this context, it may provide relief from a runny nose, sneezing, and nasal blockage caused by allergies. The use of this drug is not intended for the relief of an acute asthma attack or an allergic reaction that has already started, and it works best when used on a regular schedule.

Patients should consult the official prescribing information for comprehensive information regarding its approved uses.

Regulatory References

  1. NIH MedlinePlus guidance

Eligibility and Restrictions for Use

Who can and cannot use Flunisolide?

Official regulatory documents define the population eligibility for Flunisolide based on age, acute health status, and pre-existing conditions.

Category Official Regulatory Statement
Approved Age Groups Use is established for adults and children ge 6 years of age for both the nasal solution and inhalation forms.
Absolute Contraindications Use is prohibited for patients with known hypersensitivity to any ingredient or those experiencing an acute asthma attack or Status Asthmaticus. The nasal solution is contraindicated in the presence of an untreated localized nasal infection.
Conditional Use/Caution Caution is mandatory in patients with active or quiescent tuberculosis; untreated systemic fungal, bacterial, or viral infections; or ocular herpes simplex. Use is restricted in patients with recent nasal trauma, surgery, or septal ulcers until healing is complete.
Reproductive Status Pregnancy use is not recommended unless the benefit officially justifies the potential risk to the fetus. Caution is advised during lactation, as excretion into human milk is unknown.

Resulting eligibility structure: Regulatory guidelines explicitly classify use based on the severity of exclusion: ranging from Contraindicated for acute respiratory crises and hypersensitivity, to Use with Caution for patients with infections or recent nasal trauma. For pediatric use, safety and efficacy are not established for children younger than six years old for either formulation. The eligibility profile ensures the medicine is reserved for designated age groups and clinical situations free of absolute contraindications.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The official interaction profile for Flunisolide is primarily defined by its glucocorticoid classification and administration route. The most significant documented interactions are related to pharmacodynamic effects and specific timing rules.


Pharmacodynamic Interactions

Co-administration with Systemic Corticosteroids, such as oral prednisone, carries an officially documented risk of Additive Glucocorticoid Effects. This interaction may lead to Hypothalamic-Pituitary-Adrenal (HPA) Axis Suppression and Hypercorticism due to the cumulative systemic activity. Regulatory constraints require careful monitoring when transitioning a patient from systemic steroids to Flunisolide, due to the risk of adrenal insufficiency as systemic exposure is reduced.


Metabolic and Timing Restrictions

Flunisolide is classified in regulatory documents as a minor CYP3A4 substrate, indicating a potential interaction pathway. A mandatory Administration Timing Rule applies when Flunisolide nasal spray is used alongside Esketamine Nasal Spray; Flunisolide must be administered at least one hour prior to the Esketamine product. Additionally, Pediatric Patients are noted to have heightened susceptibility to the systemic effects (HPA axis suppression) resulting from the additive pharmacodynamic interaction. No specific interactions with food, alcohol, or herbal products are officially documented.

Mechanism of Action

Molecular Targets and Receptor Agonism

Flunisolide acts as a high-affinity agonist at the intracellular Glucocorticoid Receptor (GR). This binding initiates a genomic mechanism where the activated receptor complex translocates into the nucleus to engage in transrepression, which physically suppresses the genetic output of pro-inflammatory transcription factors, such as NF-kappaB. This action fundamentally alters the cell’s genetic instruction set, minimizing the synthesis of proteins required for mediating inflammatory responses.


Suppression of Key Inflammatory Mediators

The genomic action of Flunisolide also involves transactivation, leading to the increased production of anti-inflammatory proteins, including Annexin A1 ( Lipocortin-1). This protein indirectly inhibits the enzyme Phospholipase A2 ( PLA2), a crucial upstream step. By blocking PLA2, the drug halts the subsequent synthesis of mediators like prostaglandins and leukotrienes. Physiologically, this leads to a reduction in local vascular permeability and tissue edema (swelling).


Mechanism Limitations

Because the core anti-inflammatory effect relies on genomic changes (gene transcription and protein synthesis), the full physiological consequence is not immediate, requiring time for the physiological consequence to fully manifest. Furthermore, the mechanism is anti-inflammatory and immunosuppressive, but it does not exert any direct effect on bronchial smooth muscle and is therefore functionally inadequate for rapidly reversing acute physiological events.

Dosage and Administration Information

How to Use Flunisolide — Official Administration Guidelines

Flunisolide is an intranasal corticosteroid intended for intranasal use only. It must be used regularly, as prescribed, and not on an as-needed basis.


Dosing and Administration Scope

Age Group Usual Starting Dose Maximum Daily Limit
Adults 2 sprays per nostril, twice daily 400 mug total (8 sprays per nostril)
Children (6-14 years) 1 spray per nostril, 3 times daily, or 2 sprays per nostril, twice daily 200 mug total (4 sprays per nostril)

Procedural Requirements

Use of flunisolide is a defined procedural sequence detailed in provided instructions to ensure proper delivery of the medicine.

1. Preparation and Priming:

Before the initial use, or if the nasal spray pump has not been used for five consecutive days or more, the pump must be primed. This involves aiming the spray away from the eyes and pressing the pump until a fine spray is emitted. If the device has been cleaned, it must also be re-primed.

2. Administration Technique:

The correct technique involves gently clearing the nose (blowing the nose) before use. Insert the spray tip into one nostril while closing the other. The tip should be aimed toward the back and outer side of the nose, away from the center divider (septum). Press the pump firmly and quickly while simultaneously inhaling gently through the nose. Repeat the process for the second nostril to complete the dose.

3. Missed Dose:

If a dose is missed, it should be skipped. The next scheduled dose should be taken at the regular time. Do not double the dose to compensate for the missed one.

4. Device Maintenance:

The nosepiece/pump mechanism requires periodic cleaning as per the device instructions to prevent blockage and ensure consistent dosing. The protective cap and clip must be replaced after each use.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Flunisolide


Evidence for Use in Allergic Rhinitis (Hay Fever)

Research has evaluated Flunisolide nasal spray, examining the context of research for conditions characterized by fluctuating or episodic manifestations, such as allergic rhinitis (hay fever). The primary approach was evaluated in various short-term, randomized, controlled trials (RCTs), which typically included adult and pediatric participants whose conditions were associated with outcomes capturing phases of heightened symptom activity, such as nasal congestion, runny nose, and sneezing.

The research examined patient-reported outcomes describing perceived discomfort and changes in nasal symptoms over defined time intervals. Findings describe patterns observed in the studies regarding measured changes in these short-term symptom patterns. However, research highlights changes measured during the study period only, and results apply only to the populations studied.

Evidence for Use in Asthma

The inhaled formulation of Flunisolide was evaluated in clinical trials exploring the observations made in studies for in the research context of asthma, a condition marked by functional limitations and conditions involving periods of heightened symptoms. These studies typically monitored outcomes linked to inflammatory or irritative states in the airways, alongside measures of lung function. Data show patterns related to changes in these physiological measures in the observed study groups.

A key limitation is that comparative evidence is lacking for many direct head-to-head comparisons with other evaluated research topics. This means the full effect of using this inhaled formulation, particularly in comparison to other commonly studied treatments, appears to be an area where certainty remains low.

Long-term Studies and Follow-up

Research has explored the effects of Flunisolide over longer periods, but there is limited information for long-term outcomes that extend far beyond one year. Long-term effects are not fully established regarding the sustained changes in outcomes related to systemic or functional imbalance, such as potential effects on bone density or growth in children. Follow-up durations were limited, and data for certain groups remain insufficient when looking at the consistency of findings over many years.

Frequently Asked Questions (FAQ)

Common questions about Flunisolide (FAQ)


Q: How quickly does Flunisolide start working to relieve allergy symptoms?

Flunisolide is designed to work over time, as its anti-inflammatory effects require changes at the cellular level. Official information indicates that the full benefit of the medication may take one to two weeks of consistent, regular use to be fully realized. It is not intended for immediate, acute relief.


Q: Do you have to use Flunisolide every day, or only when you have symptoms?

Regulatory information indicates that the medication's effectiveness is based on regular use to maintain the anti-inflammatory effect in the nasal passages, rather than using it only when symptoms occur.


Q: Is it normal to experience a bad taste or smell after using Flunisolide?

An unpleasant aftertaste is reported as a side effect in official product information, as are changes in the sense of taste or smell. These effects are often related to the local administration of the nasal spray.


Q: Does Flunisolide affect the nasal septum or cause nosebleeds?

Nosebleeds, or epistaxis, are commonly reported side effects of Flunisolide in clinical trials. Additionally, the official safety information mentions the rare occurrence of nasal septal perforation (a hole in the nasal divider) as a potential serious adverse reaction associated with this class of medication.


Q: Can Flunisolide be used at the same time as other inhaled steroids for asthma?

The use of Flunisolide alongside any other corticosteroid medication, including inhaled steroids used for asthma, can increase the risk of systemic side effects, such as HPA-axis suppression. Regulatory information advises that careful monitoring is needed by a healthcare provider when combining these types of medicines.


Q: Can Flunisolide be used for non-allergy sinus issues, like a regular cold?

Flunisolide is indicated for the relief of symptoms caused by allergic rhinitis (allergies) and hay fever. Official guidance suggests it is generally not indicated to treat symptoms that are caused by the common cold.


Q: Is Flunisolide available over the counter, or is it prescription-only?

According to official regulatory classifications, Flunisolide is a prescription-only medication.


Q: Are there different strengths or formulations of Flunisolide?

Flunisolide is primarily available as an aqueous solution nasal spray in a 0.025% strength. It is also available in some regions as an inhalation aerosol for oral inhalation, which is a different formulation intended for different uses.


Q: Does taking Flunisolide weaken the immune system?

Flunisolide is a corticosteroid and possesses immunosuppressive properties, which is key to its anti-inflammatory action. Because of this, official safety information indicates it may increase the risk of localized infections and should not be used in the presence of an untreated localized nasal infection.


Q: Does Flunisolide cause drowsiness or affect energy levels?

Drowsiness is not typically listed as a common or frequent side effect for the nasal spray. However, adverse reactions such as fatigue and a feeling of lack of energy (lassitude) have been reported in regulatory documents.


Q: Will Flunisolide help with post-nasal drip?

Since Flunisolide works by reducing inflammation and fluid buildup (edema) in the nasal passages, its therapeutic effect may help relieve symptoms like runny nose and associated post-nasal drip, which are often caused by allergic inflammation.


Q: Does Flunisolide make you gain weight?

Weight gain is not consistently listed as a common side effect of the nasal spray. However, systemic effects from corticosteroids can potentially cause fluid retention and weight increase, and patients transitioning from oral (systemic) corticosteroids may experience related adverse effects.


Q: Does Flunisolide affect hormone levels?

As a glucocorticoid, Flunisolide carries a documented risk of Hypothalamic-Pituitary-Adrenal (HPA) axis suppression. This means it may affect the body’s natural ability to produce certain stress hormones, such as cortisol.


Q: Why is shaking the Flunisolide bottle before use important?

Patient instructions often advise gently shaking the container before each use. This is to help ensure the medication is properly mixed for consistent delivery of the dose.


Q: Is Flunisolide safe for use in older adults (seniors)?

Regulatory documents indicate that no specific geriatric-related problems have been uniquely documented for Flunisolide. As with many medications, caution is generally observed in older adults due to potential age-related changes in organ function.


Q: Will Flunisolide help with watery, itchy eyes as well as nasal symptoms?

While Flunisolide is indicated primarily for nasal symptoms, some prescribing information suggests its action against allergic inflammation may help relieve associated ocular symptoms, such as itchy and watery eyes caused by allergies.


Q: What research has been done on the long-term safety of Flunisolide?

Official research summaries note that studies exploring the long-term safety of Flunisolide have limitations. Follow-up periods rarely extend beyond one year, meaning long-term effects on systemic functions like growth in children or bone density are not fully established.


Q: Are there any specific foods or supplements that interact with Flunisolide?

The official prescribing information for Flunisolide explicitly states that no specific interactions with food, alcohol, or herbal products have been documented.


Q: Can Flunisolide worsen existing respiratory conditions like asthma?

The nasal solution is not to be used for acute asthma attacks or a severe form of asthma known as Status Asthmaticus, and its use is contraindicated in these acute respiratory crises. It is also restricted in the presence of certain types of infections.


Q: What is the purpose of the preservative in the Flunisolide solution?

The Flunisolide nasal solution contains inactive ingredients, such as preservatives like Benzalkonium Chloride. These substances are included to help prevent the growth of bacteria and fungi in the medication solution.


Q: Does Flunisolide contain any common allergens like lactose or gluten?

Since inactive ingredients vary by product formulation, the official product labeling provides the complete list of excipients for patients with known allergies to substances like gluten or lactose.


Q: Is it okay to stop using Flunisolide suddenly, or should I taper off?

Discontinuing any medication should be done under the guidance of a healthcare professional. Regulatory warnings emphasize that patients transitioning from systemic corticosteroids require monitoring, as sudden cessation can be associated with adrenal insufficiency or withdrawal symptoms.


Q: What should I do if Flunisolide causes irritation inside my nose?

Nasal irritation, burning, and stinging are common side effects noted in official patient information. If these symptoms are severe, worsen, or do not improve over time, or if other adverse reactions such as nosebleeds occur, consulting a healthcare professional is recommended.

How should Flunisolide be stored and disposed of?

Storage and Disposal Requirements

Flunisolide must be stored at Controlled Room Temperature, which is between 15 C to 25 C (59 F to 77 F), according to official labeling. The medication must be protected from extreme heat, moisture, and must not be frozen.

Storage Restriction Requirement
Temperature Store between 15°C and 25°C. Do not freeze.
Container Keep in its original, tightly closed container.
Protection Keep out of excess heat and moisture. Aerosol canisters must not be punctured or exposed to fire.
Child Safety Store strictly out of the sight and reach of children.

When disposing of Flunisolide, the nasal spray bottle must be discarded after the labeled number of sprays has been used. Expired or unused medicine must be disposed of safely. Patients should ask a pharmacist or local waste disposal company for instructions, and should not flush medications down the toilet or pour them down a drain unless specifically instructed.

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

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