Hicet

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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 Hicet

What is Hicet? Definition and Form

Property Description
Active ingredient Levocetirizine Dihydrochloride
Form Oral Tablets and Liquid Solutions
Pharmacological class Second-generation H₁-receptor antagonist
Common use Symptomatic relief of allergic conditions
Origin Synthetic derivative of Cetirizine

Hicet is a synthetic pharmaceutical product primarily used to treat allergic conditions, identifying it as an antiallergic medicine available in common oral dosage forms such as tablets or liquid solutions. It is administered orally for convenient systemic action, aiming to provide relief from disruptive symptoms of perennial or seasonal allergies.

This medicine is the therapeutically active enantiomer of cetirizine, known specifically as Levocetirizine.


Composition and Pharmacological Class

The key component and active ingredient of Hicet is Levocetirizine Dihydrochloride. Hicet belongs to the pharmacological class of second-generation H₁-receptor antagonists, which are widely known as non-sedating antihistamines.

As an antihistamine, Levocetirizine works by selectively blocking the effects of histamine, the natural substance released during an allergic reaction responsible for symptoms like itching and sneezing. This classification is significant as it indicates the medicine is designed to provide effective relief with a reduced potential for causing drowsiness compared to older, first-generation antihistamines.


General Therapeutic Role of Hicet

The general therapeutic purpose of Hicet is to function as an effective antipruritic (anti-itch) and antiallergic agent. It is generally used for the symptomatic management of various allergic manifestations, including allergic rhinitis (hay fever) and chronic idiopathic urticaria (hives of unknown cause).

The medicine's development as the active enantiomer is a key differentiator, positioning it as an effective modern option for patients requiring relief from recurring or persistent allergy symptoms that affect their quality of life.

Regulatory References

  1. Levocetirizine: MedlinePlus Drug Information

What side effects are possible with Hicet?

Hicet is classified as a second-generation H₁-receptor antagonist, and its official safety profile, as documented in regulatory sources, is primarily characterized by effects on the central nervous and gastrointestinal systems.

Frequency-Classified Adverse Reactions

Adverse reactions reported in clinical trials and classified as Common (affecting ge 1 in 100 people) include somnolence (drowsiness), fatigue, dry mouth, and headache. Less frequent effects, classified as Uncommon, include asthenia (weakness) and abdominal pain. Other reported events, such as aggression and visual disturbances, are classified as Not Known because their frequency cannot be estimated from the available data.

Serious Adverse Reactions and Safety Constraints

Post-marketing surveillance has documented rare but serious adverse reactions, including severe hypersensitivity reactions such as anaphylaxis and angioedema, as well as reports of hepatitis and urinary retention. The official label requires caution in patients with predisposing factors for urinary retention, such as prostatic hyperplasia.

Population-Specific Safety Considerations

The medicine is substantially excreted by the kidneys. Therefore, a major safety constraint is its use in individuals with impaired renal function. Hicet is contraindicated in patients with end-stage renal disease (ESRD) and in pediatric patients with impaired renal function. Safety documents also note that the potential for adverse reactions is generally higher in older adults due to the increased likelihood of reduced kidney function in that population.

Safety Pattern on Discontinuation

Regulatory sources also document a time-related safety pattern: severe, generalized pruritus (itching) has been reported in some individuals following the abrupt cessation of daily, long-term use.

Overdose and Emergency Response

Overdose Map: Overdose and when to seek help — official regulatory information for Hicet

Overdose Scope

  • Documented overdose presentations: Overdose manifestations primarily involve the central nervous system (CNS). In adults, the main presentation is drowsiness (somnolence). In children, the documented presentation involves an initial phase of agitation or restlessness followed by drowsiness.
  • Physiological systems affected (as stated in label): The officially documented effects directly relate to the Central Nervous System.
  • Dose-related or exposure-related factors (if applicable): Regulatory documents describe symptoms based on exposure but do not list specific dose levels associated with severe risk for all populations.
  • Population-specific overdose notes (if applicable): Overdose presentation is distinct between adults and children, with children exhibiting a biphasic response.
  • Emergency-response statements (as written in official documents): The officially required action is to provide symptomatic and supportive treatment.
  • When immediate medical help is required (label-derived phrasing only): In the event of an overdose, an individual must get medical help or contact a Poison Control Center right away.

Overdose Classifications (High-Level)

  • Severity classification (as defined in official documents): Severity is defined by the CNS effects, which necessitate seeking immediate medical attention. Specific severity grades are not universally applied.
  • Regulatory basis (EMA / FDA / etc.): The information is based on authoritative regulatory documentation, including the U.S. Food and Drug Administration (FDA) Prescribing Information.
  • Overdose-context constraints (as defined in official documents): Officially documented supportive procedures, such as dialysis, are noted to be ineffective for removing levocetirizine from the body.

Resulting Overdose Structure

  • Official overdose statements confirm that no specific antidote is known for Hicet overdose.
  • Drowsiness or somnolence is the primary documented overdose manifestation in adults.
  • Pediatric overdose presentation is noted to be agitation or restlessness preceding drowsiness.
  • The required course of action for management is symptomatic and supportive treatment.
  • It is mandatory to seek medical attention or contact a Poison Control Center immediately following a suspected overdose.
  • Regulatory data states that dialysis is not effective for drug removal in overdose management.

Connection to the overall overdose profile

Regulatory documents define the Hicet overdose profile by detailing the expected CNS effects, which include drowsiness in adults and a distinct biphasic agitation/drowsiness sequence in children. These manifestations necessitate the official mandate to seek immediate medical help or contact a Poison Control Center, with the regulatory guidance simultaneously stating that no specific antidote is known and management should focus on symptomatic and supportive care.

Therapeutic Uses of Hicet

What Hicet Treats: Main Uses and Benefits

Hicet is generally applied across domains where additional symptomatic support is needed, relevant for symptoms that interfere with daily functioning. It is primarily relevant for managing allergic rhinitis (both seasonal and perennial) and chronic idiopathic urticaria (hives).

Relief of Seasonal and Perennial Allergic Rhinitis

The medication is commonly used across conditions presenting with episodic or fluctuating manifestations, such as the symptom clusters seen in hay fever that include sneezing, runny nose, nasal stuffiness, and ocular itching. This symptomatic relief contributes to easing the overall symptom load during allergy season or persistent, year-round exposure.

Management of Chronic Idiopathic Urticaria (Hives)

In dermatological contexts, Hicet is applied in clinical settings where short-term symptomatic assistance is needed for uncomplicated skin manifestations. It is commonly used across conditions where functional stability becomes affected, such as recurrent skin itching (pruritus) and the formation of wheals. This symptomatic relief assists with maintaining functional stability during phases when symptoms become more noticeable.


Quick Fact: Supports Easing Itching and Nasal Symptoms

Regulatory References

  1. NIH DailyMed Label for Levocetirizine

Eligibility and Restrictions for Use

Hicet (Levocetirizine Dihydrochloride) is restricted to specific populations as outlined in official regulatory documentation. Exclusion is absolute for certain patient groups.

Eligibility scope

Classification Population or Condition Status
Allowed Use Adults and Adolescents (ge 12 years) Approved
Children (6 months to 11 years) Approved (Formulation Dependent)
Use Not Established Infants younger than 6 months Not Established
Contraindicated End-Stage Renal Disease ( CrCl < 10 mL/min) Prohibited
Pediatric Renal Impairment (6 months to 11 years) Prohibited
Known Hypersensitivity to levocetirizine or cetirizine Prohibited

Eligibility-Related Restrictions

  • Renal Function Integrity: Use in adults and adolescents with mild, moderate, or severe renal impairment ( CrCl 10–80 mL/min) is allowed but requires conditional use based on the degree of kidney function.
  • Hepatic Impairment: The official label states no dose adjustment is required in patients with solely hepatic impairment.
  • Special Caution: The medicine should be used with caution in patients with predisposing factors for urinary retention (e.g., prostatic hyperplasia).
  • Pregnancy Status: Use may be considered during pregnancy, if necessary, due to limited human data.
  • Lactation Status: Use is generally not recommended while breastfeeding, as the drug is likely excreted in human milk.

Official regulatory documents define who can and cannot use this medicine primarily through the patient's renal function and their hypersensitivity profile. Absolute exclusion is enforced for End-Stage Renal Disease and known sensitivities to the drug or related compounds. For all other populations, eligibility is conditionally granted, often requiring special consideration or caution based on age groups or the presence of specific comorbidities.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official regulatory documents define the interaction profile of Hicet (levocetirizine) through its effects on central nervous system (CNS) function and pharmacokinetic parameters.

Documented Pharmacodynamic and Substance Interactions

Co-administration with alcohol (Ethanol) and other Central Nervous System (CNS) depressants must be avoided. This is due to the officially documented risk of additive effects, potentially leading to additional reductions in alertness and further impairment of CNS performance.

Pharmacokinetic and Exposure-Altering Interactions

The medicine is substantially excreted by the kidneys. Its clearance can be altered by certain co-administered medicines, a finding noted in regulatory documents through studies of its racemate form (cetirizine):

  • Ritonavir: Co-administration resulted in an increase in plasma exposure (AUC) and a reduction in clearance of the racemate form.
  • Theophylline: Co-administration caused a small reduction in the clearance of the racemate form.

Administration and Food Constraints

The interaction with food is pharmacokinetic: while food does not affect the overall extent of absorption (AUC), it causes a reduction in the rate of absorption ( C max) and delays the time to peak concentration ( T max). Therefore, the medicine can be taken with or without food. No mandatory timing-based separation rules are documented for co-administration with other medicines. The use of Hicet is formally contraindicated in patients with end-stage renal disease, reflecting a major pharmacokinetic constraint tied to clearance.

Mechanism of Action

Targeted Histamine H1 Receptor Blockade

Hicet operates by engaging mechanisms that modulate cellular signaling driven by the chemical messenger histamine. The compound functions as a selective antagonist, binding to peripheral Histamine H1 receptors in various tissues. This receptor occupation modifies early molecular steps, suppressing signaling sequences that lead to histamine-mediated physiological consequences associated with high levels of mediator activity.


️ Modulation of Inflammatory Mediator Cascades

Beyond its direct receptor-mediated effect, the drug influences systems where other inflammatory mediators are dominant. Hicet initiates the suppression of select downstream cellular effects, thereby attenuating the functional consequence of non-histamine inflammatory mediators released by immune cells. This results in the modulation of signaling within targeted pathways, influencing systemic physiological adjustments driven by distinct signaling patterns.

Dosage and Administration Information

Hicet (levocetirizine dihydrochloride) is exclusively administered via the oral route, standardized across both the 5 mg film-coated tablet and the oral solution (0.5 mg/mL). The core administration principle involves a once-daily schedule, with the mandatory timing set for in the evening. The typical regimen for adults and adolescents (aged 12 years and older) uses a maximum dose of 5 mg, although a 2.5 mg dose once daily may be used if deemed appropriate.

Usage is structured by allowing intake without regard to food consumption. Procedurally, the tablets are scored to enable accurate administration of the 2.5 mg dose when necessary, and the liquid solution requires a proper measuring device. The medicine is used for both short-term intermittent conditions and as part of a long-term management plan.

Dosing guidelines are dependent on age and kidney function. Specific rules govern pediatric use: children aged 6 to 11 years receive 2.5 mg once daily, and children 6 months to 5 years receive 1.25 mg once daily. Adult patients with impaired renal function require population-specific dose adjustments; this involves reducing the frequency, potentially to 2.5 mg once every other day or less, reflecting the medicine's elimination profile.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Hicet

The research landscape for Hicet (levocetirizine) includes studies that examined its use for common allergic conditions. The findings describe patterns observed in the studies and regulatory submissions, providing context for the medicine's study landscape.


Evidence for Use in Allergic Rhinitis (Seasonal and Perennial)

Research explored Hicet's application in conditions characterized by fluctuating or episodic manifestations, such as hay fever (Seasonal Allergic Rhinitis, or SAR) and year-round allergies (Perennial Allergic Rhinitis, or PAR). This body of evidence primarily consists of short-term and intermediate-term Randomized Controlled Trials (RCTs). These studies were designed to evaluate how symptoms changed over defined periods.

Core Outcomes Studied in Rhinitis Trials

Research examined outcomes related to physical discomfort and outcomes reflecting daily functioning or activity level. Researchers monitored patient-reported outcomes describing perceived discomfort related to sneezing, a runny nose, and itching in the nose and eyes, quantified by Total Nasal Symptom Scores (TNSS) and Total Ocular Symptom Scores (TOSS). Studies also monitored Quality of Life (QoL) Scales to help contextualize how patients reported their experience.

Evidence for Use in Chronic Idiopathic Urticaria (Hives)

Hicet was studied for its application in conditions involving periods of heightened symptoms such as Chronic Idiopathic Urticaria (CIU) and Chronic Spontaneous Urticaria (CSU). Short-term, double-blind, placebo-controlled RCTs contribute to the broader evidence landscape for this application. These studies typically observed responses over defined time intervals, usually 4 to 6 weeks, which is the standard protocol for assessing chronic skin conditions.

Standardized Measurement of Urticaria Activity

The trials monitored patient-reported outcomes describing perceived discomfort by using standardized tools like the Urticarial Activity Scores (UAS/UAS7). These scores combine and measure the severity of pruritus (itching) and the number and size of wheals.

What Remains Uncertain and Gaps in the Research

Research contributes to the broader evidence landscape, but findings describe group patterns, not personal outcomes. Long-term effects are not fully established regarding the use of the medicine for periods exceeding six months. Additionally, comparative evidence is lacking from head-to-head trials against all currently available second-generation antihistamines using identical designs.

Frequently Asked Questions (FAQ)

Common questions about Hicet (FAQ)


Q: How quickly do people typically feel the effects of Hicet after taking it?

According to the official product information, the medicine is absorbed relatively quickly. Peak blood concentrations in adults are typically reached within approximately one hour after taking the oral tablet, or about 30 minutes after taking the oral solution.


Q: What is the expected duration of the effects of Hicet in the body?

Hicet is generally prescribed as a once-daily medicine. This profile aligns with the once-daily dosing schedule for sustained use, which is supported by its average plasma half-life noted as about eight to nine hours in healthy adults.


Q: Can Hicet be used for symptoms other than those listed in the official documents?

Official regulatory documents indicate that Hicet is formally authorized only for the relief of symptoms associated with allergic rhinitis (hay fever) and chronic idiopathic urticaria (hives). Use for any other medical conditions is not formally authorized by the drug label.


Q: How might Hicet affect people who are also taking certain medications for anxiety?

Official warnings describe caution regarding use with Central Nervous System (CNS) depressants, which may include some anxiety medications. Combining these medicines can potentially lead to increased drowsiness, dizziness, and decreased alertness.


Q: Is Hicet generally considered appropriate for use by children, based on regulatory data?

Hicet is indicated for use in children aged six years and older for allergic rhinitis and chronic idiopathic urticaria. Specific dosages are defined by official health authorities based on the child's age, and use is typically dependent on the appropriate formulation for younger patients.


Q: Are there specific warnings regarding the use of Hicet during pregnancy?

The official product information states that data currently available are insufficient to establish a drug-associated risk of birth defects or other specific adverse outcomes. Therefore, the medicine is used during pregnancy only if a healthcare professional determines it is clearly needed.


Q: Is Hicet considered safe for use by people who are breastfeeding, according to health authorities?

Use is generally not recommended while breastfeeding because regulatory documents indicate the medicine is likely excreted into human milk. The potential effects of this medicine on the breastfed child are currently unknown.


Q: What are the official warnings about Hicet affecting a person's ability to drive or operate machinery?

Because drowsiness (somnolence) is listed as a common adverse reaction, warnings advise against engaging in activities requiring complete mental alertness, such as driving or operating heavy machinery, until the patient has determined how the medicine affects their alertness.


Q: What kind of symptoms is Hicet officially not intended to treat?

Hicet is officially indicated only for symptoms of allergic rhinitis and chronic idiopathic urticaria. By exclusion, it is not formally indicated for non-allergic conditions such as the common cold, viral infections, or general pain.


Q: What happens if someone stops taking Hicet after using it regularly?

Post-marketing safety data documents that severe, generalized itching (pruritus) has been reported in some individuals who abruptly stop taking the medicine after daily, long-term use.


Q: What are the storage requirements for Hicet medication?

Official documents require that the medicine be stored in a closed container at Controlled Room Temperature, defined as 20°C to 25°C. For disposal of unused or expired product, the official instruction is to follow a local drug take-back program and to not flush the medicine down the sink or toilet.


Q: Does Hicet interact with other allergy medicines, such as decongestants or nasal sprays?

Official labels generally advise caution when taking Hicet with any other medicine that causes sleepiness, which may include certain decongestants found in over-the-counter products. Specific interactions with non-systemic treatments like nasal sprays are typically not documented as a concern.


Q: Does Hicet interact with any commonly used vitamins or mineral supplements?

Specific, known interactions between Hicet and common vitamins or mineral supplements are not formally documented on the drug label. However, official patient counseling information always advises patients to inform their healthcare professional about all concomitant products they are taking.


Q: Is it necessary to avoid specific herbal supplements while taking Hicet?

While the regulatory label does not list specific forbidden herbal supplements, patients are generally advised to inform their healthcare professional about any herbal products or supplements they are taking. This is standard advice due to the general potential for unknown interactions between compounds.


Q: Can Hicet be safely taken at the same time as other over-the-counter cough and cold medicines?

Many cough and cold medicines contain ingredients like CNS depressants or decongestants that may increase drowsiness. Official warnings advise caution when combining Hicet with any other over-the-counter products, and consultation with a health professional is typically advised.


Q: Is there a known interaction between Hicet and grapefruit juice?

Official drug labels state that there are no known interactions between Hicet and specific fruit juices, including grapefruit juice. The medicine can be taken with or without food.


Q: Is there any evidence for dependence or withdrawal symptoms with the long-term, non-prescribed use of Hicet?

Regulatory safety data notes that severe itching has been reported in individuals who abruptly stop taking the medicine after long-term use. Formal dependence or general withdrawal syndromes, however, are not documented on the official label.


Q: How does the body break down and eliminate Hicet once it has been taken?

The medicine is primarily eliminated by the body’s renal (kidney) system, with over 85% of the dose being excreted in the urine. Official studies indicate that the medicine is only minimally broken down (metabolized) by the liver, accounting for less than 14% of the dose.


Q: What is the standard process for reporting a possible side effect from Hicet?

Official patient counseling information advises that if you believe you are experiencing a side effect, you should report it to your prescribing doctor first. Additionally, patients are advised of the option to report side effects directly to the FDA through the MedWatch program or by contacting the medicine’s manufacturer.


Q: Is Hicet's classification as a non-sedating drug universally true for all users?

While Hicet is classified as a second-generation (non-sedating) antihistamine, official regulatory data lists drowsiness (somnolence) as a common adverse reaction reported in clinical trials. This indicates that the medicine may affect the alertness of some users.


Q: Does the packaging for Hicet include a specific Patient Information Leaflet or Medication Guide?

Official documentation encourages patients to read the instructions before using the medicine. It advises that the packaging may include a Patient Information Leaflet or a Medication Guide that provides detailed use and safety information.


Q: Does Hicet have any documented impact on fertility or reproductive health?

There is no formal statement on human fertility in the official regulatory documents. Safety studies performed on animals using the related compound, cetirizine, showed no adverse effects on reproductive health at doses relevant to human use.


Q: What are the general instructions if a dose of Hicet is forgotten?

Official patient information provides general guidance for a missed dose, typically advising patients on the process for either taking the dose as soon as remembered or skipping it if the next scheduled dose is near. The information consistently states that patients should not take a double dose.

How should Hicet be stored and disposed of?

Hicet (levocetirizine dihydrochloride) must be stored and handled according to regulatory standards to maintain its quality and efficacy. Disposal protocols must be followed to prevent environmental contamination and accidental ingestion.

Storage & Disposal Scope

Scope Item Official Regulatory Statement
Labeled storage temperature requirements Store between 20°C and 25°C (68°F and 77°F) (Controlled Room Temperature). Brief excursions are permitted to 15°C to 30°C (59°F to 86°F).
Light/moisture protection requirements Store in a dry place and away from excessive heat to prevent instability.
Packaging-related storage rules Keep the medication in the container it came in, tightly closed. Do not use if the container's safety seal is compromised.
Disposal instructions Disposal must prioritize a drug take-back program. The medicine is not on the FDA's flush list and must not be flushed down the sink or toilet.
Child-protection storage requirements The product must be kept out of reach of children at all times.

Resulting Storage & Disposal Structure

Official regulatory documents define how the product must be stored by mandating a specific Controlled Room Temperature range and requiring protection from environmental factors like excessive heat and moisture to maintain stability. The label also specifies that the medicine must be kept out of reach of children and outlines non-flush disposal procedures to be followed for unused or expired product.

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

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