Levocen

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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 Levocen

What is Levocen? A Definitional Overview

Property Description
Active Ingredient Levocetirizine (Dihydrochloride)
Form Oral Tablet, Oral Solution
Pharmacological Class Second-Generation Antihistamine
Common Use Relief of Allergic Symptoms
Origin Synthetic (R-enantiomer)

Levocen is a medicinal product containing the active substance Levocetirizine for the relief of general symptoms associated with allergic conditions. It is classified as a second-generation antihistamine, a category clinically recognized for its targeted action against allergic responses with a comparatively low potential for generalized central nervous system effects.

Levocetirizine belongs to the piperazine derivatives chemical class and is administered exclusively via the oral route. It is typically available as a film-coated oral tablet or an oral solution or syrup, offering suitable forms for both adult and pediatric patient groups.


Levocetirizine: Synthetic Origin and Composition

The chemical substance Levocetirizine is a synthetic compound, specifically the R-enantiomer of the older drug, cetirizine. This designation means Levocetirizine is the isolated, active mirror-image form (the eutomer) responsible for the therapeutic effect.

Its formulation utilizes the Levocetirizine dihydrochloride salt. This isolation of the single active isomer, achieved through a process known as a chiral switch, provides a highly targeted anti-allergic action, which is a key pharmacological feature of the product.


What is the General Purpose of Levocen?

The general purpose of Levocen is to mitigate the physiological manifestations and widespread general discomfort resulting from an allergic reaction, such as those caused by seasonal environmental factors. As a selective H1 receptor antagonist, its primary function is to block the binding of histamine, which is the chemical mediator released upon exposure to allergens.

By performing this specific histamine blockade, the medication provides reliable symptomatic relief for the general signs of allergy, including itching (pruritus), mild swelling, and runny nose or watery eyes.

Regulatory References

  1. Levocetirizine
  2. second-generation antihistamine
  3. oral solution

What side effects are possible with Levocen?

Possible side effects and safety information

The official safety profile for Levocen (Levocetirizine) is structured according to regulatory classifications, detailing documented adverse reactions by frequency and the body system affected. The information strictly reflects findings from clinical trials and post-marketing surveillance, and does not constitute medical advice or instructions for use.

Adverse Reaction Classifications

Adverse reactions are formally categorized based on their documented incidence in regulatory sources:

  • Common Reactions (Frequently Observed): These include effects such as somnolence (sleepiness), fatigue, headache, and dry mouth. These effects are generally classified under Nervous System Disorders and Gastrointestinal Disorders.
  • Uncommon Reactions: These include documented effects such as agitation and abdominal pain.
  • Rare Reactions (Infrequently Observed): The label documents events such as severe hypersensitivity reactions, convulsions, tachycardia (fast heart rate), and abnormal liver function tests.
  • Frequency Not Known: Post-marketing reports have included serious events such as aggression, suicidal ideation, and urinary retention, whose incidence cannot be estimated from available data.

Official Safety Constraints

Specific limitations for Levocetirizine use are defined in regulatory labeling based on physiological conditions:

  1. Contraindications: Use is strictly contraindicated in patients with a known hypersensitivity to levocetirizine or any piperazine derivatives (the drug's chemical class). It is also contraindicated in patients with severe renal impairment (creatinine clearance less than 10 mL/min).
  2. Population Considerations: Caution is advised for older adults due to the higher probability of decreased renal function. The medication is also contraindicated in pediatric patients under two years of age.
  3. Exposure Patterns: Regulatory documents note that severe pruritus (itching) has been reported in some instances upon the discontinuation of long-term daily use of the drug.

Overdose and Emergency Response

Overdose and When to Seek Help for Levocen

Documented Overdose Manifestations

The official regulatory profile for Levocetirizine overdose centers on central nervous system (CNS) effects. The primary documented clinical sign observed in adults is drowsiness (somnolence). A distinct presentation is noted in children, whose overdose may initially present as agitation or restlessness, preceding the manifestation of drowsiness. These differences in initial symptomology are explicitly documented in regulatory sources.

Immediate Actions and Management

Regulatory labeling explicitly mandates that individuals must seek emergency medical attention immediately if any overdose is suspected or has occurred. Patients or caregivers are required to call the Poison Help line or other emergency services without delay, as immediate professional clinical supervision is necessary.

Management is restricted to symptomatic or supportive treatment, as the official documentation confirms there is no known specific antidote for Levocetirizine. For recent, short-term ingestion, medical guidance suggests considering gastric lavage. Furthermore, the regulatory profile provides the procedural note that Levocetirizine is not effectively removed by haemodialysis, defining critical limitations for detoxification procedures.

Therapeutic Uses of Levocen

What Levocen Treats: Main Uses and Benefits

Levocen (levocetirizine) is commonly used to help with symptoms related to inflammatory or irritative states caused by allergic reactions, contributing to easing the overall symptom load associated with acute or chronic allergy episodes. It is applied in addressing a variety of allergic symptoms, including those associated with seasonal allergies and hives.

It is commonly used across conditions characterized by recurrent or episodic manifestations of allergic rhinitis (seasonal hay fever and year-round perennial allergies) and for the symptomatic management of Chronic Idiopathic Urticaria (long-lasting hives). It helps provide supportive relief for symptoms that may fluctuate, and may help patients cope more steadily with symptom fluctuations.

Key Symptom Domains

The medication is relevant for easing symptoms in conditions presenting with localized discomfort that create noticeable physiological strain. It helps address symptom clusters that may become intense or disruptive, such as runny nose, sneezing, nasal itching, watery eyes, and intense skin itching (pruritus). This application supports the patient during difficult episodes by easing distress and contributes to improved comfort during periods of heightened symptoms.

“It is considered relevant in clinical settings marked by persistent symptoms, and can be applied during episodes of sudden symptom escalation.”


Brief Symptom Summary Levocen is used for managing symptoms that may become intense or disruptive, including intense itching and the physical appearance of wheals and flares associated with hives.

Regulatory References

  1. National Institutes of Health (NIH) MedlinePlus overview

Eligibility and Restrictions for Use

Levocen (levocetirizine) is an antihistamine for which official eligibility is strictly defined by age, kidney function, and history of immune reaction.

Eligibility and Exclusion Criteria

Classification Patient Group/Condition
Allowed Use Adults and children 6 months of age and older (specific formulation dependent)
Contraindicated Use Patients with known hypersensitivity to levocetirizine, cetirizine, or any components in the formulation.
Contraindicated Use Patients with end-stage renal disease (creatinine clearance <10 mL/min) or those undergoing hemodialysis.
Contraindicated Use Pediatric patients 6 months to 11 years of age with any degree of impaired renal function.
Not Established Safety and effectiveness have not been established in children younger than 6 months of age.

For adults and children 12 years and older with mild to severe renal impairment, use is restricted and requires a dose adjustment based on the measured reduction in kidney function. Caution is also advised for elderly patients due to the higher likelihood of decreased kidney function and for patients with conditions predisposing them to urinary retention.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official regulatory documentation structures the interaction profile of Levocen (levocetirizine) around pharmacodynamic and pharmacokinetic patterns, particularly concerning central nervous system effects and clearance.

Key Documented Interaction Patterns

Interaction Type Interacting Substance/Condition Documented Outcome and Restriction
Pharmacodynamic Alcohol (Ethanol) and CNS Depressants Concurrent use must be avoided due to the risk of additive impairment of central nervous system performance and reduced alertness.
Pharmacokinetic Ritonavir Co-administration may increase levocetirizine plasma concentrations due to decreased total body clearance.
Metabolic CYP Enzymes (e.g., 3A4, 2D6) Levocetirizine is unlikely to produce or be subject to clinically relevant metabolic interactions as its metabolism is low.

Administration and Population Notes

The medication can be administered with or without food as the overall extent of exposure (AUC) is not affected, although the maximum plasma concentration is reduced. The drug’s clearance is significantly reduced in populations with impaired renal function and in elderly subjects (65–74 years) due to its dependence on renal elimination. Patients with end-stage renal disease (CLCR < 10 mL/min) and pediatric patients (6–11 years) with impaired renal function are a contraindicated population.

Mechanism of Action

High-Affinity Inverse Agonism at Peripheral H1 Receptors

The primary mechanism involves Levocetirizine acting as a highly selective inverse agonist on the Histamine H1 Receptor (H1R) located in peripheral tissues. By stabilizing the receptor in an inactive conformation, the drug effectively blocks the binding of histamine and suppresses the entire downstream signaling cascade, which is fundamental to modulating the downstream effects of histamine signaling.

Sustained Receptor Occupancy and Modulating Vascular Dynamics

A defining characteristic is the drug's slow dissociation kinetics, resulting in prolonged receptor occupancy. This continuous action modulates the signaling that controls vascular permeability and vasodilation. Furthermore, the drug exerts a secondary mechanism by inhibiting the signaling required for eosinophil migration, contributing to the modulation of signaling that affects inflammatory cell infiltration.

Resulting Physiological Changes

These combined actions result in three core physiological changes: the control of histamine-driven capillary fluid extravasation, the inhibition of H1R activity on peripheral sensory neurons, and the modulation of signaling that affects inflammatory cell infiltration. The high peripheral selectivity of the molecule ensures that these physiological effects are concentrated outside of the central nervous system.

Dosage and Administration Information

Levocen (levocetirizine) is administered exclusively by the oral route, available as a 5 mg film-coated, scored tablet and an oral solution (0.5 mg/mL). The general procedural structure mandates once-daily intake, typically scheduled for evening administration.

The standard adult and adolescent dosage (age 12 and older) is 5 mg once daily. Pediatric dosing is differentiated by age: children 6 to 11 years are administered 2.5 mg once daily, and younger children (6 months to 5 years) receive 1.25 mg once daily using the oral solution. The 5 mg tablet is scored, allowing it to be broken to administer the 2.5 mg dose when appropriate.

Levocen may be taken with or without food, as absorption extent is not affected by meal timing. Treatment duration is guided by the condition's nature; for intermittent use, administration is stopped when symptoms disappear and resumed upon return, while continuous therapy may be proposed for chronic conditions.

Dose modification is required for patients with impaired renal function. The dosage for adults and adolescents with decreased creatinine clearance must be adjusted based on the severity of the impairment, ranging from 2.5 mg once daily for mild cases to 2.5 mg twice weekly for severe cases. No dose adjustment is specified for isolated hepatic impairment.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Levocen

This overview describes the types of research conducted for levocetirizine (Levocen), the specific outcomes researchers monitored, and what remains uncertain, based solely on authoritative clinical and regulatory sources.


Evidence for Use in Seasonal Allergic Rhinitis (SAR)

Research used in exploring how symptoms change during periods of high pollen or allergen exposure has primarily been conducted using Randomized Controlled Trials (RCTs). These short-term studies are relevant in trials assessing short-term or episodic symptom patterns. Researchers examined outcomes related to physical discomfort, such as aggregated scores for sneezing, runny nose, nasal itching, and watery eyes. Studies conducted during periods of increased symptom activity monitored symptom patterns in the observed populations. Some trials described patterns where the severity of reported symptoms was observed during the short study period, which contributes to the evidence base for this condition. Long-term effects are not fully established regarding durability across multiple allergy seasons.


Evidence for Use in Perennial Allergic Rhinitis (PAR)

For perennial allergic rhinitis, research has explored trials of longer duration. The evidence primarily stems from longer-duration Randomized Controlled Trials, some of which have monitored patients over multiple months. These studies were applied in research contexts involving fluctuating or unstable symptoms and were designed to track outcomes related to systemic or functional imbalance, such as patient-reported measures of daily functioning. Data for certain groups remain insufficient, as most dedicated long-duration RCTs focused on Adults and Adolescents.


What is Still Uncertain About Levocen

While research describes the patterns observed so far, several aspects are not fully established. Evidence quality varies across studies, and some early studies have presented mixed findings or inconsistent results. The follow-up durations were limited in many studies, meaning long-term effects are not fully established beyond the intermediate term. Specifically, documented research gaps indicate that data for certain groups remain insufficient, particularly the elderly population and patients with complex or refractory conditions. The research highlights what is known—and what is still uncertain—about this medicine.

Frequently Asked Questions (FAQ)

Common questions about Levocen (FAQ)


Q: How quickly should I expect Levocen to start working?

Studies examining the medication’s use indicate that symptomatic improvement has been observed as early as one day after beginning Levocen therapy. The drug's mechanism is consistent with providing relief over the once-daily dosing interval.


Q: Does Levocen cause drowsiness or fatigue?

Yes, official product information lists somnolence (sleepiness) and fatigue as commonly reported adverse reactions documented during clinical trials. Due to the possibility of these effects, official warnings advise caution regarding activities that require complete mental alertness and motor coordination.


Q: Is it common to have stomach upset after taking Levocen?

Regulatory information indicates that abdominal pain is reported as an uncommon reaction. Other general gastrointestinal effects have also been documented in various studies.


Q: Are there any foods or drinks that should be avoided while using Levocen?

Official regulatory documents state that alcohol and other central nervous system depressants should be avoided. This is because combining them may increase the risk of drowsiness or reduced alertness. The medication itself can be taken with or without food.


Q: Is Levocen safe for older adults (seniors)?

Caution is advised for older adults due to the naturally higher probability of decreased kidney function. Because the drug is mainly eliminated by the kidneys, this decreased function can affect the drug's clearance. Regulatory documents describe dose adjustments for older patients with impaired kidney function.


Q: Can Levocen be crushed or split, or must it be swallowed whole?

The 5 mg tablet formulation of the medication is scored. This scoring allows the tablet to be broken in half to administer a lower dose when instructed by a healthcare professional.


Q: What kind of research has been done on Levocen's effectiveness?

The evidence base for the medication primarily consists of Randomized Controlled Trials (RCTs). These studies have been designed to examine changes in physical discomfort symptoms and track outcomes related to systemic function, often relying on patient-reported scores.


Q: What is the typical time frame to be on Levocen?

Treatment duration is determined by the specific condition being treated. Studies have examined its use over periods as short as two weeks for seasonal allergies and for up to several months for more chronic conditions.


Q: If I miss a dose of Levocen, what is the best thing to do?

Official patient information indicates that if a dose is missed, it should be taken as soon as it is remembered, unless it is almost time for the next scheduled dose. If so, the missed dose is skipped, and the regular schedule is continued. Official patient information indicates that a double dose should not be taken to compensate for a missed one.


Q: Is Levocen available over the counter in some countries?

In the United States, the medication is available both by prescription and as an over-the-counter (OTC) product. Its specific regulatory status may vary in other countries globally.


Q: Does Levocen have a risk of addiction or dependence?

The official regulatory labeling and detailed product information do not list addiction, abuse potential, or dependence as a known risk associated with this medication.


Q: Why do some people say Levocen didn't work for them?

Official reviews of the research evidence note that there is a degree of variability in patient response observed across different studies. Furthermore, some early studies have reported mixed or inconsistent findings, which may contribute to varying individual experiences.


Q: Does Levocen affect birth control pills?

Current official regulatory information does not list an interaction between this medication and hormonal birth control pills.


Q: Can Levocen cause changes in mood or anxiety?

Documented adverse reactions include agitation, which is listed as uncommon. Post-marketing reports have also included serious effects such as aggression and suicidal ideation, though their frequency is not known from available data.


Q: Is it true that Levocen can cause sensitivity to the sun?

Increased sun sensitivity (photosensitivity) is not listed among the documented common, uncommon, or rare adverse reactions in the official regulatory product information.


Q: Is Levocen a long-term or short-term treatment?

The medication is used for both short-term, intermittent relief when symptoms appear, and for continuous, longer-term therapy for chronic conditions. The prescribed duration depends entirely on the nature of the condition being managed.


Q: Is Levocen commonly prescribed for people with kidney or liver issues?

While no dose adjustment is specified for isolated liver impairment, dose modification is a regulatory requirement for patients with any degree of impaired kidney function. Use is prohibited in cases of severe kidney impairment.


Q: Why does the packaging for Levocen include a special warning?

Official labeling includes warnings necessary to ensure safe use, such as those related to central nervous system impairment and the risk of urinary retention. An additional warning addresses the risk of severe itching (pruritus) that may occur upon discontinuing the medication after long-term use.


Q: Do you have to stop Levocen gradually, or can you stop suddenly?

Official warnings note that stopping the drug suddenly after using it long-term may result in a severe rebound of itching (pruritus). Information linked to this warning discusses potentially reducing the dose gradually to lessen this reaction.


Q: Is it possible to be allergic to Levocen?

Yes, it is possible to be allergic to the active substance or to other medicines that belong to the same chemical class. Hypersensitivity reactions are listed in the official safety profile as a contraindication and a rare adverse reaction.


Q: How long does Levocen stay in the body after the last dose?

The rate at which the drug leaves the body is described by its mean elimination half-life, which is typically between eight and nine hours.


Q: Is Levocen used for treating more than one medical condition?

Yes, the medication is approved for treating symptoms related to more than one condition. This includes seasonal and perennial allergies, as well as the uncomplicated skin manifestations of chronic hives (chronic idiopathic urticaria).


Q: Does Levocen have any known severe side effects?

Official labeling documents rare, severe adverse reactions that have been reported, such as convulsions, severe hypersensitivity reactions, and fast heart rate (tachycardia). Post-marketing reports also include serious events like suicidal ideation, for which the incidence rate is not known.


Q: Can I drive or operate machinery after taking Levocen?

The official warning advises caution regarding activities that require complete mental alertness and motor coordination, such as driving or operating machinery. This caution is advised until it is known how the medication affects an individual's response.


Q: What if I take Levocen without a meal?

The medication may be taken with or without food. Official administration notes state that the overall amount of drug absorbed by the body is not affected by the timing of meals.


Q: Are there any known drug-disease interactions with Levocen?

Yes, regulatory documents list known drug-disease interactions. These include the need for caution in patients with conditions that predispose them to urinary retention and the requirement for dose adjustment in patients with impaired kidney function.


Q: Is Levocen considered a high-risk medication during pregnancy?

The medication is classified by the FDA as Pregnancy Category B. This classification indicates that animal reproduction studies have not demonstrated a risk to the fetus, but there are no adequate and well-controlled studies in pregnant women.


Q: What is the experience of people who have used Levocen for several months?

Clinical trials have monitored patients over multiple months for chronic conditions. One notable safety observation associated with long-term use is the rare risk of severe itching upon discontinuing the medication.


Q: How reliable is the evidence supporting the use of Levocen?

Official regulatory reviews note that while there is an evidence base, evidence quality varies across different studies. Additionally, some early studies have presented mixed or inconsistent results.


Q: Is it safe to drink alcohol while taking Levocen?

Official regulatory information advises that the use of alcohol should be avoided. This is due to the risk of additive impairment of central nervous system performance, which may increase the chance of drowsiness or reduced alertness.


Q: Are there any special considerations for people with heart problems taking Levocen?

The official safety profile documents tachycardia, or a fast heart rate, as a rare adverse reaction that has been reported.


Q: What is the earliest age someone is generally eligible to use Levocen?

The medication is approved for use in children six months of age and older, with specific formulations and dose adjustments necessary for younger age groups based on official guidelines.


Q: Do studies show Levocen works equally well for all approved conditions?

Research for the different approved conditions, such as seasonal allergies versus chronic hives, was often conducted in separate studies. These studies monitored specific, relevant outcomes and do not directly compare the efficacy across all approved conditions.


Q: Are there specific times of day that are best for taking Levocen?

The general procedure mandates that the medication be taken once daily. It is typically scheduled for administration in the evening.


Q: How do researchers measure the success of Levocen in clinical trials?

Researchers in clinical trials measure success by tracking changes in physical symptoms such as sneezing and itching. They also monitor outcomes related to systemic function, often using validated, patient-reported symptom scores.

How should Levocen be stored and disposed of?

How to Store and Dispose of Levocen?


Official Storage Requirements

Levocen (levocetirizine) must be stored at Controlled Room Temperature, typically 20 C to 25 C (68 F to 77 F), according to official regulatory labeling. The medicine must be kept in its original container, which should remain tightly closed, and stored in a dry place away from excessive heat and moisture. Do not use the product after the labeled expiry date.

Child-Safety and Disposal

It is a mandatory safety requirement to store Levocen out of the sight and reach of children.

Disposal of unused or expired Levocen must be performed in accordance with local regulatory requirements. The preferred method is using a drug take-back location. If placed in household trash, the tablets must first be mixed with an undesirable substance (e.g., dirt or coffee grounds) and sealed in a container.

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

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