Ayrinal

Bilastine

Method of action: Antihistamines For Systemic Use

Treatment option:

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 Ayrinal

What is Ayrinal?

Ayrinal is a pharmaceutical medication primarily utilized for its antihistamine properties. It belongs to a class of drugs known as second-generation H1-receptor antagonists. These medications are designed to block the action of histamine, a natural substance in the body that triggers inflammatory and allergic responses.

Mechanism of Action

The active component in Ayrinal works by selectively binding to peripheral H1 receptors. By preventing histamine from attaching to these receptors, the medication helps to mitigate the physiological processes that lead to common allergic symptoms. As a second-generation antihistamine, it is engineered to have limited penetration across the blood-brain barrier, which generally results in a lower incidence of central nervous system effects, such as drowsiness, compared to older antihistamine formulations.

Therapeutic Intent

Ayrinal is used to manage symptoms associated with various allergic conditions. These typically include:

Allergic Rhinitis: Inflammation of the nasal passages caused by allergens such as pollen, dust mites, or animal dander. It addresses symptoms like sneezing, nasal congestion, and an itchy or runny nose.
Urticaria: A skin condition characterized by the sudden appearance of itchy, raised welts or hives. The medication helps reduce the redness and itching associated with chronic or acute outbreaks.
Allergic Conjunctivitis: Allergic reactions affecting the eyes, leading to redness, itching, and watering.

Physical Characteristics

Ayrinal is typically produced in oral solid dosage forms, such as tablets. The formulation is developed to provide a sustained effect, often allowing for once-daily administration to maintain consistent levels of the medication in the bloodstream throughout the day.

Regulatory References

Bilastine: Limited Blood-Brain Barrier Passage

What side effects are possible with Ayrinal?

Possible Side Effects and Safety Information

The official safety profile of Ayrinal (Bilastine) is formally defined by adverse reactions classified by frequency and grouped into System-Organ Classes (SOCs), based on data from regulatory sources.

Frequency-Classified Adverse Reactions

The most frequently documented effects in clinical trials involving adults and adolescents are classified as Common (ge 1/100 to < 1/10), which include Headache and Somnolence (Drowsiness).

Reactions classified as Uncommon (ge 1/1,000 to < 1/100) span several systems, including Psychiatric Disorders (e.g., Anxiety, Insomnia), Gastrointestinal Disorders (e.g., Nausea, Diarrhea, Dry mouth), and Cardiac Disorders (e.g., Sinus arrhythmia, ECG abnormal). Laboratory changes such as increased liver enzyme levels and increased weight are also documented as uncommon.

Serious Adverse Reactions and Population Notes

Serious Adverse Reactions such as severe Hypersensitivity reactions, including Anaphylaxis and Angioedema, have been reported in post-marketing surveillance, with their frequency classified as Frequency Not Known (cannot be estimated from available data).

Population-Specific Safety Notes are included in official documentation. For patients with Renal Impairment or Hepatic Impairment, no dose adjustment is generally required for Bilastine itself. However, caution is noted in patients with moderate or severe renal impairment if taking concomitant P-glycoprotein inhibitors, as this can increase Bilastine plasma concentrations. Furthermore, the bioavailability of the medicine is officially noted to be significantly reduced when taken with fruit juice, which is a key safety-related administration restriction.

Overdose and Emergency Response

Ayrinal Overdose and When to Seek Help

The regulatory documentation for Ayrinal (Bilastine) provides the official profile for overdosage, primarily established through clinical studies conducted in healthy volunteers exposed to high doses. In these trials, involving up to 11 times the standard therapeutic dose, the most commonly documented clinical manifestations were dizziness, headache, and nausea. It is officially noted that acute overexposure up to the tested limits resulted in no serious adverse events and no significant prolongation in the QTc interval.

In the event of suspected overdosage, immediate action is required as stated in the prescribing information. Users must promptly contact the regional poison control centre for guidance and management. The officially recommended clinical strategy involves providing symptomatic and supportive treatment, as regulatory data confirms there is no known specific antidote to bilastine. Due to general regulatory constraints, Electrocardiogram monitoring is recommended for continuous observation following an overdosage event. The official label also notes that there are no data for overdose in children available from the clinical trial experience reviewed. This information is intended solely to describe the documented overdose presentation and mandated actions.

Therapeutic Uses of Ayrinal

Ayrinal (Bilastine) is primarily applied across domains where additional symptomatic support is needed. Its therapeutic scope focuses on providing symptomatic relief for two core domains: allergic reactions affecting the upper airways and eyes, and specific chronic skin conditions.

Symptomatic Relief for Allergic Rhinitis and Eye Symptoms

The medication is commonly used across conditions characterized by periods of heightened symptoms, including seasonal allergic rhinitis (hay fever), perennial allergic rhinitis (year-round allergies), and Chronic Spontaneous Urticaria (hives). Ayrinal is relevant for managing symptoms that interfere with daily comfort, which may include sneezing, runny nose (rhinorrhea), nasal itching, and watery, itchy eyes. Providing symptomatic relief may help patients cope more steadily with difficult episodes and contributes to easing the overall symptom load.

Managing Chronic Allergic Skin Manifestations (Hives)

In this domain, Ayrinal is applied in addressing symptoms that create noticeable physiological strain, and may assist with managing pruritus (itching) and the presence of raised, red wheals. A key therapeutic role is its use in scenarios where symptoms that interfere with daily functioning require relief. It may assist with maintaining functional stability and supports general well-being during symptomatic phases.

Quick Fact: Symptomatic management for Pruritus (Itching) and Nasal Symptoms

Regulatory References

Health Canada Product Monograph

Eligibility and Restrictions for Use

Ayrinal (bilastine) is primarily intended for adults and adolescents aged 12 years and older for the treatment of symptoms associated with allergic rhinoconjunctivitis (such as hay fever) and urticaria (hives).

Contraindications

The most important contraindication is a known allergy or hypersensitivity to bilastine or any of the inactive ingredients in the medication. Individuals with this specific allergy must not use Ayrinal.

Cautions and Special Populations

While Ayrinal is generally well-tolerated and dose adjustments are typically not required, certain groups should consult a healthcare provider before use. These include:

Children under 12 years of age: The drug is not recommended for this age group due to insufficient data on efficacy and safety.
Patients with moderate to severe renal impairment (kidney problems): Although bilastine is primarily excreted unchanged, patients should discuss their kidney function with a doctor.
Pregnancy and Breastfeeding: Use during pregnancy or while breastfeeding should only occur after a thorough risk-benefit assessment by a physician.

It is also important to note that taking Ayrinal with food or fruit juice significantly reduces its absorption, making it less effective. It should be taken one hour before or two hours after eating.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The official regulatory documentation for Ayrinal establishes a drug interaction profile primarily focused on substances that share or influence the same biological pathways. The key regulatory concern centers on agents that may affect the central nervous system or cardiac function, often requiring specific prescribing consideration.

Interaction Scope	Description from Official Sources
Central Nervous System (CNS) Depressants	Co-administration with other depressants, including sedatives, tranquilizers, or alcohol, may lead to additive effects, potentially increasing drowsiness, sedation, or impaired coordination.
QTc-Prolonging Drugs	Official labeling indicates that concurrent use with other medications known to prolong the QTc interval must be approached with caution due to an increased risk of specific cardiac rhythm disturbances. This involves a broad range of drug classes.
CYP Enzyme Systems	The drug's metabolism involves specific Cytochrome P450 isoenzymes, and therefore, strong inhibitors or inducers of these enzymes may significantly alter the blood levels of Ayrinal. This pharmacokinetic interaction necessitates monitoring or adjustment.

Pharmacokinetic interactions are formally documented as a critical constraint, particularly regarding the clearance of Ayrinal, which is often mediated by the body's primary drug-metabolizing systems. This structural focus ensures that clinical decisions are made to maintain the drug’s intended exposure profile while mitigating the risks associated with altered drug levels or additive effects on the heart or CNS. No specific timing or separation requirements are uniformly mandated for all interactions, but careful patient monitoring is specified in cases of concomitant therapy.

Mechanism of Action

How Ayrinal Works

Ayrinal's action is defined by the highly focused pharmacodynamics of its active ingredient, Bilastine. The mechanism is designed to modulate specific physiological consequences of activity within the histamine signaling pathway.

Selective H1 Receptor Inverse Agonism

Bilastine operates by engaging in selective H1-receptor inverse agonism primarily in peripheral tissues. This molecular interaction actively locks the receptor into an inactive state, reducing the activation state of the Gq signaling cascade associated with histamine-induced cellular effects.

Modulation of Vascular and Sensory H1 Receptor Activity

The interruption of the H1 signaling cascade modifies molecular events that influence systemic physiological parameters. The mechanism alters histamine-dependent signaling within blood vessel walls, influencing permeability, and decreases the responsiveness of peripheral sensory nerve endings to histamine. This sequence of events results in altered signaling dynamics within the targeted pathways.

Physiological Constraints of the Mechanism

The mechanism is functionally confined to processes mediated by the H1 receptor and does not interfere with pathways involving other pro-inflammatory mediators. Due to the pathway-modulating nature of its action, the mechanism does not provide the rapid, direct physiological counter-action necessary for immediate systemic crises.

Dosage and Administration Information

Administration Guidelines for Ayrinal (Intranasal Spray)

Ayrinal is an intranasal spray intended for use only in the nose. Proper administration is essential for ensuring the correct dose is delivered.

Dosing and Preparation

Administration Scope	Stipulation
Route of Administration	Intranasal route only
Dosing Schedule (Adults/Adolescents age 12 or older)	Two sprays per nostril twice daily (e.g., morning and evening)
Preparation Requirements	Priming is mandatory before first use and following a period of non-use of three or more days.
Missed Dose Rule	If a dose is missed, take the next dose at the regularly scheduled time. Do not take a double dose to compensate.

Step Sequence for Administration

The following procedural steps are required:

Prime the device by actuating the pump 4 times or until a fine mist is released before the first use. If the spray has not been used for 3 or more days, re-prime with 2 sprays or until a fine mist appears.
Administer two sprays into the first nostril.
Administer two sprays into the second nostril.
Repeat this process twice daily for the duration of use.

Important Procedural Conditions

Special attention must be paid to administration conditions. The product must not be sprayed into the eyes. The dosage and frequency are fixed: two sprays per nostril, two times per day. The patient-oriented instructions focus solely on the mechanical action and timing of the delivery system.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Ayrinal

Evidence for Symptomatic Relief of Allergic Rhinitis (Hay Fever and Year-Round Allergies)

Research exploring Ayrinal (bilastine) for allergic rhinitis relies primarily on short-term, randomized controlled trials (RCTs). These studies were used in research exploring how symptoms change over time by comparing the outcomes of patients taking the medicine against those receiving a placebo or another common allergy medicine. Studies monitored patient-reported outcomes describing perceived discomfort, such as sneezing, nasal itching, and watery eyes.

Studies observed differences in the measured total symptom scores between the group receiving Ayrinal and the placebo group. Research highlights changes measured during the study period for both seasonal and perennial manifestations. However, regulator reviews have noted that results were not entirely uniform across all pivotal studies. Comparative evidence is lacking for direct comparisons against all similar medications, and long-term outcomes are not fully established based on these initial RCTs.

Evidence for Managing Chronic Hives (Chronic Spontaneous Urticaria)

Ayrinal was also evaluated in clinical research contexts involving fluctuating or unstable symptoms of chronic spontaneous urticaria (CSU). Randomized controlled trials were applied in studies examining patient-reported experiences related to this condition, which is characterized by the presence of raised, itchy welts (wheals). The main outcomes monitored measured changes in pruritus (itching) severity and the presence of wheals. Research also explored the study of higher dose administration in settings examining persistent symptoms.

Studies conducted during periods of increased symptom activity reported that symptom severity scores and quality of life measures showed changes over the short-term study period. Evidence describes the study of symptom control in patients previously identified as having had an unsatisfactory response to standard antihistamine treatment. However, evidence is limited when considering the long-term effects of sustained exposure for many months or years.

Evidence in Specific Age Groups (Special Populations)

Research has been conducted to evaluate the administration of Ayrinal in children, specifically those aged 6 to under 12 years. The evidence for children relies on pharmacokinetic (PK) studies and safety/tolerability trials rather than large efficacy trials. These PK studies monitored systemic exposure by measuring drug concentration to compare whether the pediatric dose produced systemic exposure values similar to those reported in adults. These studies are fundamental to the process of comparing systemic exposure for the pediatric dose to the adult dose.

Consequently, dedicated long-term research providing comparative insight into symptom patterns in children remains limited. Efficacy for this group is inferred based on the research finding of similar drug concentrations to adults, rather than by new, large-scale studies directly measuring symptom relief against a placebo in young children.

Frequently Asked Questions (FAQ)

Common questions about Ayrinal (FAQ)

Q: Is Ayrinal a type of antihistamine or something different?

A: Ayrinal contains the active ingredient Bilastine, which is officially classified as a synthetic second-generation H1-antihistamine. Its intended effect, as documented in official information, is to counteract the effects of histamine, a substance involved in allergic symptoms.

Q: How quickly should I expect Ayrinal to start working for my symptoms?

A: Official information indicates that Ayrinal is associated with rapid absorption. While regulatory documents do not provide a precise time frame (like minutes or hours) for the onset of action, this feature contributes to its overall profile.

Q: Can children take Ayrinal, and if so, is it the same formulation as for adults?

A: Ayrinal is primarily intended for use in adults and adolescents aged 12 years and older. For children under 12, regulatory documents indicate that its use is not recommended due to insufficient data on efficacy and safety. Specific formulations were studied for younger children to compare drug concentrations to those found in adults.

Q: Is Ayrinal a prescription-only medication, or can I buy it over the counter?

A: In many countries, Ayrinal is generally designated as a prescription-only (Rx) medication. Its status may vary by region; individuals can refer to their local pharmacy or regulatory body for confirmation.

Q: Are there generic versions of Ayrinal available?

A: Ayrinal is the brand name for the active ingredient, Bilastine. Generic versions containing Bilastine may be available, subject to regulatory approval in a given country.

Q: Are there any common foods or drinks that should be avoided while on Ayrinal?

A: Official regulatory documents state that taking Ayrinal with fruit juices, including grapefruit juice, should be avoided. This is because fruit juices can significantly reduce the absorption of the medicine, making it less effective.

Q: Is it safe to take Ayrinal if I am also taking an anxiety medication?

A: Official labeling advises caution when Ayrinal is used with Central Nervous System (CNS) depressants, which can include certain anxiety medications. This co-administration may lead to additive effects, potentially increasing drowsiness or sedation. Patients are advised to inform a healthcare provider of all concomitant medications.

Q: Is Ayrinal considered a long-term treatment or is it only for short-term use?

A: The duration of treatment is determined by a healthcare professional based on the specific condition being treated, such as seasonal or perennial allergies. Regulatory safety studies have supported its use for up to one year.

Q: Can Ayrinal affect blood pressure or heart rate?

A: The official safety profile notes that Ayrinal can, in rare instances, cause changes in the heart's electrical activity. Fast or irregular heartbeat is listed as a potential serious side effect, and regulatory information advises a cautious approach for patients with existing heart conditions.

Q: Is Ayrinal safe for someone with kidney problems?

A: According to official regulatory documents, a dose adjustment for Ayrinal is generally not required for patients with kidney problems (renal impairment). However, regulatory information notes that caution is advised if the patient is simultaneously taking specific other medicines that can affect Ayrinal’s plasma concentration.

Q: Are there any reports of Ayrinal causing changes in mood or sleep?

A: Official regulatory documents list Anxiety and Insomnia (difficulty sleeping) as uncommon side effects. Conversely, Somnolence (drowsiness) is reported as a common side effect.

Q: Is Ayrinal approved for use during pregnancy or while breastfeeding?

A: Ayrinal should generally be avoided during pregnancy unless a physician determines the potential benefit outweighs the potential risk, as comprehensive studies are limited. Regarding breastfeeding, the regulatory information indicates that a clinical decision must balance the benefits of the drug to the mother against the risks to the infant.

Q: Does Ayrinal contain gluten, lactose, or common allergens?

A: The ingredients of Ayrinal are fully disclosed in regulatory documents. Some tablet forms of Ayrinal may contain excipients like lactose. Individuals with known allergies or sensitivities should review the full ingredient list with a healthcare professional.

Q: Can people who drive or operate heavy machinery safely take Ayrinal?

A: While Ayrinal is classified as non-sedating, it can still cause side effects such as drowsiness or dizziness in some individuals. Official guidance states that because the medicine may cause drowsiness or dizziness, individuals should assess their response to the drug before driving or operating machinery.

Q: Are there specific times of day when Ayrinal is most effective to take?

A: Official regulatory guidance requires that Ayrinal be taken once daily. The official guidance for optimal absorption states that it should be taken either one hour before or two hours after food or fruit juice. There are no instructions suggesting a particular time of day offers greater effectiveness.

Q: Can Ayrinal be crushed or chewed, or must the pill be swallowed whole?

A: The standard tablet formulation is intended to be swallowed whole with water. Some tablets may have a score line to make them easier to swallow, but this does not authorize crushing or chewing unless it is an Orodispersible Tablet (ODT) form.

Q: Is Ayrinal compatible with common vitamins and mineral supplements?

A: Regulatory documents list interactions with specific drug classes. While there is no general statement regarding common vitamins or mineral supplements, patients are encouraged to inform a healthcare provider of all concomitant products to check for potential interactions.

Q: Does Ayrinal require any special monitoring or follow-up blood tests?

A: Routine special monitoring or blood tests are not mandated for all users of Ayrinal. However, a healthcare professional may require additional monitoring if the patient has certain underlying heart conditions or is taking other specific medications that could affect Ayrinal's concentration in the body.

Q: Is there a maximum time limit for how long one can safely take Ayrinal?

A: The duration of treatment is determined by the prescribing physician. While the duration of treatment is determined by a physician, regulatory safety studies have supported continuous use for periods up to one year.

How should Ayrinal be stored and disposed of?

Storage Requirements

Official regulatory documents state that Ayrinal (Bilastine) does not require any special storage conditions in terms of temperature or environment. The medicine must be kept safely stored until the expiry date (EXP) printed on the carton and blister packaging; usage after this date is prohibited.