allacan

Quick links to important sections

Medically reviewed

Rosario Oropesa

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 allacan

Property Description
Active ingredient Cetirizine Hydrochloride
Form Film-coated tablet, Oral solution/syrup
Pharmacological class Second-generation antihistamine
Common use Relief of allergic symptoms
Origin Synthetic (derived chemical entity)

What Type of Medicine is Allacan and Its Core Composition?

Allacan is a medicine whose core component is the active substance Cetirizine Hydrochloride (INN), a compound clinically recognized for its role in allergy management and formally classified as a second-generation antihistamine. This substance functions as a selective Histamine H1-receptor antagonist, meaning it acts specifically to inhibit the peripheral H1 receptors that drive allergic reactions in the body. The active molecule is synthetic in origin, stemming chemically from the piperazine derivatives group, and is consistently formulated as a single-ingredient product. Allacan is commonly available in the form of a 10 mg film-coated tablet, a characteristic strength recognized globally for this type of medication.

How Does Allacan Generally Help the Body?

The primary therapeutic function of Allacan is to provide symptomatic relief associated with allergic manifestations, such as those caused by seasonal hay fever or chronic urticaria. Cetirizine is a highly selective peripheral histamine H1-receptor antagonist used for the treatment of various allergic conditions. This means the medication effectively reduces the severity of symptoms like sneezing, itching, and watery eyes caused by the body's overreaction to triggers. By competitively occupying the receptors intended for histamine, the drug mitigates the body's inflammatory cascade, providing continuous, systemic symptom control to individuals experiencing reactions to common environmental triggers.

Available Forms and Medicinal Origin

Allacan is supplied for oral administration, most frequently as a compact, film-coated tablet designed for easy ingestion, though it is also available in liquid forms like an oral solution or syrup suitable for pediatric or adult patients who prefer this format. The synthetic creation of the Cetirizine Hydrochloride molecule ensures a reliable chemical profile and efficacy. This oral delivery ensures the medication is systemically distributed to provide widespread relief across various areas of the body affected by allergic processes.

Regulatory References

  1. medical literature reviews

What side effects are possible with allacan?

Possible Side Effects and Safety Information

The safety profile of Cetirizine Hydrochloride (Allacan) is organized in regulatory documents according to System Organ Classes (SOCs) and frequency categories based on clinical and post-marketing data. These classifications detail the possible range and likelihood of adverse reactions.

Frequency Classification of Documented Effects

The most commonly documented adverse reactions, classified as Common (may affect up to 1 in 10 people), primarily relate to the Nervous System Disorders and General Disorders groupings. These include somnolence (drowsiness), fatigue, headache, and dry mouth. Reactions classified as Uncommon (may affect up to 1 in 100 people) include agitation, abdominal pain, and rash.

Less frequently, reactions are listed as Rare or Very Rare. Rare reactions (may affect up to 1 in 1,000 people) include hypersensitivity reactions, convulsions, and abnormal hepatic function tests. The most serious adverse reactions documented as Very Rare (may affect up to 1 in 10,000 people) include anaphylactic shock.

Population-Specific Safety Notes and Constraints

The medicine is officially contraindicated in individuals with a known hypersensitivity to the active substance or its derivatives. Due to its clearance pathway, it is also contraindicated in patients with severe renal impairment (creatinine clearance less than 10 ml/ min). Regulatory guidance notes that caution should be applied for older adults and patients with any degree of renal impairment due to the potential for altered clearance, which may necessitate a lower dose. Some common effects, such as somnolence and fatigue, are noted in official labeling as usually transient, often appearing more frequently at the beginning of treatment.

Overdose and Emergency Response

Overdose and when to seek help

Documented Overdose Manifestations

Overdose manifestations for Cetirizine (Allacan) primarily involve the Central Nervous System (CNS) and are often documented as being dose-related. Common signs cited in regulatory sources include somnolence (drowsiness), fatigue, dizziness, and headache. Gastrointestinal effects such as diarrhea have also been reported. In pediatric cases, manifestations may specifically include restlessness and irritability as prominent initial symptoms, typically followed by drowsiness. Rare, severe outcomes cited in regulatory information include convulsions and tachycardia (fast heart rate).

Urgent Help-Seeking and Management

Regulatory guidance emphasizes that emergency medical help must be sought immediately in cases of suspected overdose. It is mandated to call the Poison Control Center for guidance. An immediate call to emergency services is required if the affected individual has collapsed, had a seizure, has trouble breathing, or cannot be awakened. Management of overdose is symptomatic and supportive, as the official label states there is no known specific antidote. Procedures such as gastric lavage may be considered shortly after ingestion in a clinical setting. The drug is not effectively removed by dialysis.

Therapeutic Uses of allacan

What Allacan Treats: Main Uses and Benefits

This medication is generally used in situations involving certain distressing symptoms of allergic origin. It is applied across domains where additional symptomatic support is needed, primarily to help manage symptoms that interfere with daily functioning and contribute to easing the overall symptom load.

The medication is commonly used across conditions presenting with acute episodes and recurrent manifestations, including seasonal allergic rhinitis (hay fever), perennial allergic rhinitis, and chronic idiopathic urticaria (hives).

Symptomatic Relief for Allergic Rhinitis and Ocular Discomfort

Allacan is relevant for managing symptom clusters that may become intense or disruptive, such as constant sneezing, a persistent runny nose, nasal itching, and irritating eye symptoms like tearing and redness. This supportive relief is particularly helpful during phases of increased distress or discomfort associated with high allergen exposure.

“The medication is considered relevant to support patients during difficult episodes by easing the intensity of common allergic manifestations.”

Managing Chronic Itching and Hives (Urticaria)

The medication is also relevant in clinical settings marked by increased discomfort or tension from allergic skin manifestations. It is applied in cases where symptoms create noticeable physiological strain, specifically to ease challenging symptoms like intense generalized body itching (pruritus) and to assist with managing the occurrence and severity of chronic hives. This provides support that helps ease the overall symptom burden, contributing to maintaining functional stability when symptoms are more noticeable.


Quick Fact: Symptomatic support for Persistent Allergic Itching

Regulatory References

  1. NIH MedlinePlus overview

Eligibility and Restrictions for Use

Eligibility Map: Who Can and Cannot Use Allacan

Official regulatory documents define the population eligibility for Allacan (Cetirizine Hydrochloride) based on age, existing health conditions, and physiological status.

Populations Contraindicated for Use

  • Hypersensitivity: Individuals with a known allergy to the active substance, any inactive ingredients in the formulation, or to related compounds like hydroxyzine or other piperazine derivatives.
  • Severe Organ Impairment: Patients with severe end-stage renal disease, defined as having a creatinine clearance of less than 10 mL/min.

Age-Related Eligibility

  • Allowed: Use is established for adults and adolescents (12 years and older) under standard labeled conditions.
  • Children: Eligibility is established for children aged 6 to 11 years (typically tablets) and for those aged 2 to 5 years (typically oral solution).
  • Limitations: Use is generally not recommended for infants and children under 2 years of age.

Condition-Specific Eligibility Rules

  • Renal Impairment: Use is restricted in patients with moderate renal impairment (creatinine clearance 10 to 50 mL/min), requiring conditional use.
  • Special Caution: Regulatory labels recommend caution for patients with epilepsy or those at risk of convulsions, and for individuals with predisposing factors for urinary retention (e.g., prostatic hyperplasia).
  • Hepatic Impairment: No dose adjustment is typically needed for isolated hepatic impairment, but this population is noted for consideration.

Physiological Status Eligibility

  • Pregnancy and Lactation: Use is generally not recommended during pregnancy and breastfeeding, as the active substance is known to pass into breast milk.

What should I know about interactions with other medicines?

Official Interaction Patterns

Allacan's official interaction profile is defined by two primary types of effects documented in government regulatory labeling, with no combinations formally classified as contraindicated based on interaction risk alone.

Pharmacodynamic and CNS Interactions

Co-administration with alcohol (ethanol) or other Central Nervous System ( CNS) depressants, such as sedatives or tranquilizers, carries a formal warning for an additive pharmacodynamic effect. This combination may result in an increased reduction in mental alertness and further impairment of performance. This restriction is based on the documented potential for reinforcing CNS depression.

Pharmacokinetic Interactions

The pharmacokinetic profile of Allacan is largely unaffected by co-administered drugs; however, an exception is officially documented with Theophylline. Studies show that co-administration of a 400 mg once-daily dose of Theophylline results in a statistically significant decrease of approximately 16% in Cetirizine clearance, which leads to a corresponding increase in its overall systemic exposure ( AUC). Official data confirms Allacan has a negligible potential to interact through major Cytochrome P450 enzymes.

Administration-Related and Population Notes

Food intake does not affect the total amount of medicine absorbed, but it officially delays the time required to reach peak plasma concentration ( T max) by around 1.7 hours. Furthermore, the regulatory labeling notes that clearance is inherently reduced in patients with pre-existing hepatic or renal impairment, a factor that increases the risk of drug accumulation and potential severity of any co-administered interaction.

Mechanism of Action

Allacan, containing cetirizine, functions as a highly selective antagonist of the peripheral histamine H1 receptor (H1). It exhibits negligible binding affinity for other receptors, including muscarinic, serotonergic, and adrenergic receptor sites.

By occupying the H1 receptor, cetirizine blocks the binding of the endogenous signaling molecule histamine. Histamine binding normally triggers a Gq/11 protein-coupled cascade, leading to the activation of phospholipase C (PLC) and subsequent hydrolysis of PIP2 into IP3 and DAG. This intracellular cascade results in increased intracellular calcium concentration, driving cellular effects like increased vascular permeability and smooth muscle contraction.

Antagonism of the H1 receptor by cetirizine prevents this downstream signaling. At the cellular level, this blockade leads to the modulation of inflammatory cell function, including the suppression of eosinophil chemotaxis and the regulation of cytokine and chemokine release, an effect partially independent of H1 receptor antagonism.

System-level physiological consequences include a reduction in capillary fluid leakage and the inhibition of histamine-induced smooth muscle bronchospasm, primarily in the respiratory and cardiovascular systems.

Dosage and Administration Information

Allacan (cetirizine hydrochloride) is primarily administered via the oral route, available as a film-coated tablet or an oral solution. The established dosing regimen for most healthy adults and adolescents (12 years and older) is 10 mg, taken once daily. The maximum dose is not to exceed 10 mg in a 24-hour period.

There are contextual timing guidelines clarifying that the oral forms can be administered with or without food, allowing flexibility in scheduling the daily intake. While the single 10 mg dose is the standard frequency, a divided 5 mg twice-daily schedule is often used for children aged 6 to 11 years.

Specific population-based adjustment rules exist for procedural adherence: a dose reduction is required for adult patients with moderate to severe renal impairment, often involving a decrease to 5 mg once daily or a dose taken every two days. For acute clinical needs, an intravenous injection of 10 mg may be administered, which must be given as an intravenous push over 1 to 2 minutes in a monitored setting. The tablet formulation is not recommended for children under six years due to the difficulty in achieving precise dose adaptation.

Recent Clinical Evidence

Allacan (Cetirizine) Clinical Evidence

Allacan contains the active ingredient cetirizine hydrochloride, a second-generation, non-sedating antihistamine. The medication is widely studied, and clinical evidence supports its use for relieving symptoms associated with specific allergic conditions.

Allergic Rhinitis (Hay Fever)

Controlled clinical trials consistently indicate that cetirizine is associated with the relief of nasal and ocular symptoms related to both seasonal allergic rhinitis (SAR) (hay fever) and perennial allergic rhinitis (PAR) (year-round allergies). These symptoms typically include sneezing, rhinorrhea (runny nose), and pruritus (itching) of the nose and eyes. Research suggests that cetirizine's effect on symptoms, such as the wheal and flare reactions induced by histamine in the skin, generally begins within 20 to 60 minutes after administration and may last for 24 hours.

Chronic Urticaria (Hives)

Cetirizine is also supported by evidence as a treatment for chronic idiopathic urticaria (CIU), or hives with no identifiable cause. Clinical studies show that it may help reduce the severity of symptoms, specifically pruritus and the presence of wheals (hives). Current guidelines from major allergy organizations recognize second-generation antihistamines, including cetirizine, as a primary pharmacological option for managing chronic urticaria.

Efficacy and Safety Profile

Studies comparing cetirizine to first-generation antihistamines and placebo generally observe that cetirizine provides symptom relief while minimizing the possibility of adverse sedative effects commonly associated with older treatments. Evidence from the pediatric population (children aged 6 to 12) suggests cetirizine is well-tolerated and may improve clinical symptoms and quality of life in children with allergic rhinitis, though an increased risk of somnolence (drowsiness) was noted in some comparative meta-analyses.

Frequently Asked Questions (FAQ)

Common questions about allacan (FAQ)

Q: What is the main difference between allacan and cetirizine?

Allacan is a brand name for a medicine whose active substance is cetirizine hydrochloride. Official regulatory documents describe cetirizine as a second-generation antihistamine, which is the component that works to relieve allergy symptoms.

Q: Does allacan interact with alcohol?

Official regulatory warnings state that taking this medicine alongside alcohol may result in an additive effect that increases the potential for reduced mental alertness and performance impairment. This is due to reinforcing Central Nervous System (CNS) effects.

Q: How long does it take for allacan to start working?

Research evidence indicates that the effects of the active ingredient may typically begin to provide symptom relief within 20 to 60 minutes after a dose is taken.

Q: Is allacan safe to take every day?

Official documents describe the safety profile for chronic, daily administration in adults and adolescents. There are rare post-marketing reports of severe itching (pruritus) upon stopping the medicine after continuous daily use for a few months or longer.

Q: Can allacan be used for a rash that is not an allergy?

The documented clinical evidence supports the use of the active ingredient for specific allergic conditions, such as allergic rhinitis and chronic urticaria (hives). Official core labeling focuses on these uses.

Q: Do I need a prescription to get allacan?

The active ingredient in Allacan, cetirizine, is commonly available in many regions as an over-the-counter (OTC) medicine. This means it can typically be purchased without needing a prescription from a healthcare provider.

Q: Does allacan affect sleep?

The most commonly documented side effects include somnolence (drowsiness) and fatigue. These are known effects on the Central Nervous System (CNS) that can potentially influence a person's level of alertness or sleep patterns.

Q: Is allacan safe for children under 12?

Official eligibility is established for specific age groups. For example, use is supported for children aged 6 to 11 years and 2 to 5 years. Use is generally not supported for children under 2 years of age in regulatory labeling.

Q: Are there any long-term side effects from using allacan?

Official labeling notes that common effects like drowsiness are usually transient. However, there are rare post-marketing reports of severe itching, or pruritus, which has been reported after stopping the medicine following daily use for a few months or longer.

Q: Is allacan the same as generic XYZ drug?

Allacan is a brand name for the active ingredient, cetirizine hydrochloride. This active ingredient is also available from other companies under numerous other generic and brand-name formulations worldwide.

Q: Can allacan cause anxiety?

Anxiety is not listed among the common side effects described in official regulatory labeling. Adverse reactions classified as Uncommon (less frequent) include agitation, which is a state of distress or restlessness.

Q: Is allacan useful for pet allergies?

The active ingredient is approved to relieve symptoms of respiratory allergies, such as those caused by indoor and outdoor triggers. This includes common environmental allergens like pets and dust mites.

Q: What kind of studies have been done on allacan?

The clinical evidence for the active ingredient is based on controlled clinical trials for its efficacy in relieving symptoms of allergic rhinitis and chronic urticaria. Its safety profile is also supported by comparative meta-analyses against older treatments.

Q: Does allacan lose its effect over time?

Official documentation does not describe a loss of efficacy, or tolerance, over time when the drug is taken as directed. Studies confirm the active substance does not accumulate in the body with chronic administration.

Q: How long does allacan stay in your system after stopping?

According to the pharmacokinetics data in official documents, the active ingredient is primarily excreted by the kidney. Its plasma elimination half-life, which describes the rate of clearance from the plasma, is approximately 8.3 hours.

Q: Is the research evidence for allacan considered strong?

Clinical evidence from controlled trials indicates the medicine's association with relief of allergic symptoms. Current guidelines from major allergy organizations recognize the active ingredient as a primary pharmacological option for managing specific allergic conditions.

Q: What time of day is best to take allacan?

The standard dose is taken once daily. Official instructions clarify that the oral forms can be administered with or without food, allowing flexibility in scheduling the daily intake.

Q: Can allacan affect the results of an allergy skin test?

Antihistamines like the active ingredient in Allacan can suppress the skin response to histamine. Official guidance states the medicine should be discontinued for a specified period before an allergy skin test to avoid interference with the results.

Q: Is it okay to crush or chew allacan tablets?

Allacan is commonly supplied as a film-coated tablet designed for oral ingestion. Official guidance on the film-coated tablet form typically does not include instructions for crushing or chewing, as the coating helps ensure proper administration.

Q: Does allacan cause weight gain?

Official regulatory documents categorize and list the possible side effects of the medicine. Weight gain is not listed among the common (Common, Uncommon, Rare) side effects in the official safety profile.

Q: Is allacan known by a different name in other countries?

Yes. While Allacan is a specific brand name, the active substance is cetirizine hydrochloride, which is the internationally recognized name and is marketed under various brand names in different countries.

Q: What are the ingredients in allacan besides the active one?

Official regulatory documents list the inactive ingredients (excipients), which are necessary for the drug's formulation. These non-active ingredients vary by the form of the medicine and typically include things like cellulose, lactose, and film-coating agents.

Q: Is allacan generally considered safe for use?

When used according to regulatory instructions, the medicine is classified as having an established favorable safety profile. Official documents detail known risks, including specific contraindications and a list of possible side effects categorized by frequency.

Q: What is the difference between allacan and a decongestant?

Allacan is classified as a second-generation antihistamine that works by targeting peripheral H1 receptors to control the allergic reaction. Decongestants are a separate pharmacological class that typically works by constricting blood vessels to relieve nasal stuffiness.

Q: Can allacan be used for chronic conditions?

Yes, the medicine is supported by clinical evidence for treating symptoms of perennial allergic rhinitis (PAR), which is a year-round condition, and chronic idiopathic urticaria (CIU) (hives).

Q: Can I stop taking allacan suddenly without issues?

Official documents note that there are rare post-marketing reports of severe itching (pruritus) that can occur within a few days after stopping daily use for several months or longer. Restarting the medicine has been noted to resolve this effect in some individuals.

Q: Can allacan be taken on an empty stomach?

Official instructions provide contextual timing guidelines, clarifying that the oral forms can be administered with or without food. This means the medicine may be taken on an empty stomach.

Q: What happens if you take more allacan than recommended?

Regulatory documents list symptoms of an overdose, which may include restlessness, irritability, and drowsiness. The official approved dose is not to exceed 10 mg in a 24-hour period.

Q: Why does the packaging of allacan say to avoid certain activities?

Official warnings exist due to the risk of somnolence (drowsiness) and potential impairment of mental alertness. This risk is noted to be increased when the medicine is taken with alcohol or other Central Nervous System (CNS) depressants.

How should allacan be stored and disposed of?

How to Store and Dispose of Allacan (Cetirizine Hydrochloride)

Official regulatory documents require that Allacan film-coated tablets be stored at Controlled Room Temperature, specifically a temperature not exceeding 25 C (77 F). The medicine must be kept in the original package to maintain its integrity and stability. Use of the product is prohibited after the expiry date printed on the label.

For safety, the medication must be kept out of the sight and reach of children at all times.

Regarding disposal, regulatory instructions state that unused or expired Allacan must not be thrown away via wastewater or household waste. Instead, individuals are instructed to consult a pharmacist for guidance on proper disposal, which ensures adherence to environmental protection requirements.

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

Available in countries:

Equivalent of allacan found in:

A-Z Index: