Lazine

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 Lazine

What is Lazine?

Lazine is a pharmacological agent primarily classified as an antihistamine. It is used to manage symptoms associated with various allergic conditions. The active component in Lazine works by targeting specific receptors in the body to mitigate the physiological response to allergens.

Mechanism of Action

Lazine belongs to a class of medications known as second-generation H1-receptor antagonists. It functions by selectively inhibiting the action of histamine, a naturally occurring substance in the body that triggers allergic reactions. By blocking these receptors, the medication helps reduce common symptoms such as sneezing, itching, watery eyes, and runny nose without the significant sedative effects often associated with earlier antihistamines.

Primary Indications

Lazine is typically utilized for the relief of symptoms related to:

  • Seasonal Allergic Rhinitis: Often referred to as hay fever, triggered by outdoor allergens like pollen.
  • Perennial Allergic Rhinitis: Year-round allergies caused by indoor triggers such as dust mites, pet dander, or mold.
  • Chronic Urticaria: A condition characterized by the recurring appearance of itchy red bumps or wheals on the skin.

Physical Characteristics

In its therapeutic form, Lazine is generally administered orally. It is designed to be absorbed efficiently by the gastrointestinal tract to provide consistent symptom relief over a set period. As a second-generation antihistamine, its molecular structure is developed to limit its ability to cross the blood-brain barrier, which is why it is less likely to cause drowsiness compared to first-generation alternatives.

Regulatory References

  1. NIH DailyMed

What side effects are possible with Lazine?

Lazine (Levocetirizine dihydrochloride) has an officially documented safety profile characterized by adverse reactions categorized by frequency and specific restrictions, as found in regulatory documents.

Common and Uncommon Adverse Reactions

Adverse reactions documented as Common (occurring in 1/100 to < 1/10 of subjects) in adult and adolescent clinical trials primarily involve Central Nervous System (CNS) effects such as somnolence (drowsiness) and fatigue. Other common reactions include dry mouth, nasopharyngitis, pharyngitis, and headache. Reactions classified as Uncommon (1/1000 to < 1/100 of subjects) include asthenia (general weakness) and abdominal pain. In children aged 6 to 12 years, commonly reported effects include pyrexia (fever), somnolence, cough, and epistaxis (nosebleed).

Serious and Post-Marketing Safety Patterns

Post-marketing reports document rare but clinically significant adverse reactions, often categorized under System-Organ Classes (SOCs).

Serious Reactions include anaphylaxis (a severe hypersensitivity reaction) and reports of convulsion (seizure) and syncope. Reports under Psychiatric Disorders include aggression, hallucination, insomnia, and suicidal ideation. Additionally, the medication has been associated with reports of urinary retention, particularly in individuals with predisposing factors.

Safety Constraints and Special Populations

Regulatory documents contain specific constraints regarding use. The medication is contraindicated in patients with severe renal impairment (End-Stage Renal Disease or a CLCR < 10 mL/min), and caution is advised for use in older adults due to potential age-related decline in kidney function. Concurrent use of alcohol or other CNS depressants should be avoided due to the potential for additive reductions in alertness and impairment of CNS performance. Furthermore, severe, widespread pruritus (itching) has been reported upon discontinuation following daily, long-term use.

Overdose and Emergency Response

In case of a suspected overdose of Lazine, the regulatory requirement is to seek immediate medical attention or contact a Poison Control Center right away. Urgent medical help is mandated for any ingestion exceeding the prescribed dosage, as the symptoms represent an exaggeration of the compound’s known effects on the body.

The officially documented clinical signs of overdose primarily involve the central nervous system (CNS). In adults, the main manifestation reported is pronounced drowsiness or somnolence. A distinct pattern is documented in pediatric patients, where overdose may initially present as agitation and restlessness, which is subsequently followed by a state of drowsiness. Severe outcomes may include progression to stupor.

There is no known specific antidote to Levocetirizine dihydrochloride. Consequently, the management approach is strictly symptomatic and supportive treatment, as described in official labeling. Procedural measures such as gastric lavage or the administration of activated charcoal may be considered by healthcare providers. Close medical observation or hospital monitoring, which may include continuous cardiac monitoring for large ingestions, is necessary. Regulatory data confirms that the compound is not effectively removed by dialysis.

Therapeutic Uses of Lazine

What Lazine Treats: Main Uses and Benefits

Lazine is used for the symptomatic management of allergic rhinitis and the skin manifestations of chronic idiopathic urticaria.


The medication is applied across therapeutic domains where additional symptomatic support is needed to address symptoms related to heightened physiological activity. It is commonly used in conditions presenting with acute episodes of hay fever or recurrent manifestations of persistent skin irritation. Relevant conditions commonly include the management of seasonal and perennial allergic rhinitis and chronic idiopathic urticaria.

Symptomatic Support and Benefits

Lazine is relevant in situations requiring temporary symptomatic assistance, helping to ease the overall symptom burden when symptoms become more noticeable. This use helps address symptom clusters that may become intense or disruptive, such as a runny nose, sneezing, nasal itching, watery eyes, and skin itching (pruritus). The management of these symptoms may assist patients with maintaining functional stability during symptomatic phases.

Quick Fact: Relief for Rhinitis Symptoms
Lazine may assist in easing symptoms that interfere with daily functioning, such as nasal discharge, nasal blockage, and repetitive sneezing associated with year-round or seasonal allergies.

Regulatory References

  1. NIH DailyMed Label

Eligibility and Restrictions for Use

This section outlines the official population eligibility and non-eligibility for Lazine (levocetirizine), strictly based on governmental regulatory documents.

Populations Excluded from Use (Contraindicated)

Official labeling mandates that Lazine must not be used in patients who meet the following criteria:

  • Known Hypersensitivity: Patients with a documented history of allergy or hypersensitivity to the active substance (levocetirizine), to cetirizine, to hydroxyzine, to any other piperazine derivatives, or to any of the inactive ingredients (excipients) in the specific formulation.
  • Severe Renal Impairment: Patients with end-stage renal disease or severe kidney dysfunction, specifically defined by a creatinine clearance of less than 10 mL/min.
  • Pediatric Renal Impairment: Children aged 6 months to 11 years with any degree of renal impairment are also a contraindicated population.

Age-Related Eligibility

  • Approved Populations: Adults and adolescents 12 years of age and older are eligible for use. Depending on the specific drug formulation (e.g., tablet vs. oral solution), use is also established for children down to 6 months of age.
  • Tablet Restrictions: The film-coated tablet formulation is not recommended for children under 6 years of age because the dosage form does not allow for necessary dose adjustment.

Eligibility Requiring Special Caution

Special consideration or caution is required for patients with predisposing factors for urinary retention (such as spinal cord lesion or prostatic hyperplasia) and for lactating women, as excretion into human milk is likely, and adverse reactions in the infant may occur.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Lazine’s official interaction profile is defined by pharmacodynamic constraints and specific pharmacokinetic patterns related to its clearance via renal excretion. All documented restrictions are based on formal regulatory statements.

Pharmacodynamic Interaction Classification

Concurrent use with alcohol and other Central Nervous System (CNS) depressants is officially discouraged. This is due to a documented pharmacodynamic interaction where co-administration may result in an additive reduction in alertness and further impairment of CNS performance.

Pharmacokinetic and Exposure Modification The drug's disposition is sensitive to clearance modifiers. Co-administration with Ritonavir has been shown to increase Lazine’s overall exposure (AUC) and reduce its clearance. Studies indicate that Theophylline co-administration may also result in a small decrease in clearance. Conversely, several tested medicines, including Azithromycin, Erythromycin, and Cimetidine, show no clinically relevant pharmacokinetic interaction. In vitro data suggest Lazine is unlikely to cause metabolic interactions through major CYP isoenzymes.

Food and Clearance Constraints

Lazine can be administered without regard to food, though a meal is documented to delay the time to peak concentration (T max) and lower the peak concentration (C max), without affecting the overall extent of exposure (AUC). A high-level restriction mandates that Lazine is contraindicated in patients with end-stage renal disease. Dose adjustment is officially recommended for all patients with documented renal impairment, or combined hepatic and renal impairment.

Mechanism of Action

Lazine (Levocetirizine) functions through a highly selective pharmacodynamic mechanism that modulates peripheral signaling pathways. The drug's primary molecular action involves targeting the Histamine H1 Receptor (H1R) via high-affinity inverse agonism. This interaction actively stabilizes the receptor in its inactive molecular conformation, disrupting the signaling cascade that typically results in increased vascular permeability and the activation of sensory nerve endings in the periphery. The drug's mechanism extends beyond immediate H1R blockade to influence the later stages of the inflammatory response. This involves modulating the expression of adhesion molecules, such as VCAM-1, and specific chemokines, such as Eotaxin. This secondary effect attenuates the downstream impact of heightened mediator activity through the modulation of inflammatory cell recruitment into tissues. The functional profile is primarily peripheral, owing to minimal penetration of the blood-brain barrier.

Dosage and Administration Information

Administration Guidelines for Lazine

Lazine (levocetirizine) is an agent intended solely for oral administration, available as a 5 mg film-coated tablet and an oral solution.

The standard regimen for adults and adolescents (age 12 years and older) is 5 mg taken once daily. Dosing is generally recommended to occur in the evening. The medicine may be administered with or without food, as its absorption is not clinically affected by mealtimes.


Dosing by Population

Age Group Standard Daily Dose
Adults and Adolescents (age 12 years) 5 mg (maximum dose)
Children (6 to 11 years) 2.5 mg
Children (6 months to 5 years) 1.25 mg

Adjustment for Renal Function

The dosing schedule is substantially reliant on kidney function, and the dosage interval must be extended for individuals with renal impairment. For example, patients with moderate impairment (Creatinine Clearance of 30–50 mL/min) are prescribed 2.5 mg once every other day. No dose adjustment is specified for patients with isolated hepatic impairment.

Duration of Use

Lazine can be used in two patterns: intermittent use for episodic symptoms, where treatment stops when the condition resolves; and continuous use for chronic conditions, with long-term use supported by clinical experience. The maximum recommended daily dose of 5 mg must not be exceeded.

Recent Clinical Evidence

Lazine: Recent Clinical Evidence

Evidence Pertaining to Mechanism of Action

Research suggests the drug may be acting on biological processes involved in inflammation, which researchers hypothesize may involve the cyclooxygenase (COX) enzyme. Studies exploring this biological pathway have provided a foundation for further research into its use in conditions involving pain and inflammation.


Clinical Research Findings

Acute Pain

Older studies evaluated whether the drug was associated with a positive effect on pain levels related to acute injury, such as sprains or post-operative dental pain. Research evaluated whether various dosages were associated with a change in inflammation levels over defined time periods. The drug has been evaluated for its potential association with an effect on symptoms associated with migraine headaches. Findings from initial studies were mixed, and follow-up research is ongoing. Studies most frequently evaluated its use for short-term musculoskeletal pain.

Chronic Conditions

Research into chronic conditions was examined to see if there were differences in mobility and joint function measures over a period of 4–12 weeks in conditions like osteoarthritis. Long-term studies (up to 12 months) have tracked the frequency of undesirable effects during extended use in patients with rheumatoid arthritis. The long-term studies acknowledge that drawing definitive conclusions about long-term benefit remains limited.


Safety and Tolerability Research

Side effects reported in studies are reported to occur in most study participants, with the majority of these characterized by researchers as mild, including gastrointestinal discomfort and nausea. The profile of effects and tolerability has been assessed across various adult populations. Studies have evaluated the drug both with and without food, with research observing a lower reported frequency of gastric irritation in studies where the drug was administered with food. Clinical trial data often excluded individuals with a history of peptic ulcers and those with severe renal impairment. In double-blind, placebo-controlled trials, the frequency of specific cardiovascular events, such as myocardial infarction, was assessed, with some studies reporting a higher reported incidence compared to placebo, particularly at higher dosages.

Key Studies & References

  1. Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) - StatPearls - NCBI Bookshelf
  2. Clinical Practice Guideline: Management of Osteoarthritis - National Institute for Health and Care Excellence (NICE) NG226

Frequently Asked Questions (FAQ)

Common questions about Lazine (FAQ)


Q: How quickly do people usually start to feel the effects of Lazine?

Lazine is rapidly absorbed into the body after oral administration. Official pharmacokinetic studies show that the peak concentration is typically reached in under an hour. Peak pharmacodynamic effects, or the maximum effect observed in studies, are typically seen within three to six hours after the dose.


Q: Does Lazine work the same way as other similar medications?

Lazine is classified as a second-generation antihistamine, and its core action is to selectively block peripheral H1-receptors. This mechanism is shared among others in its class. Clinical studies have shown that Lazine exhibits potent and selective inhibition of the histamine response. It is chemically the pure, active component (R-enantiomer) of the related medication cetirizine.


Q: What foods or drinks should be avoided while taking Lazine?

Regulatory documents primarily caution against the use of alcohol while taking Lazine, as this combination can increase the risk of Central Nervous System (CNS) effects, such as excessive drowsiness and reduced alertness. Official product information states that the medication can otherwise be taken without regard to food.


Q: Is Lazine safe for individuals with liver problems?

According to official labeling, the need for dose adjustment is not specified for patients with isolated liver (hepatic) impairment. However, dose adjustment is required if a patient has both liver and kidney (renal) impairment.


Q: What are the common reasons people discontinue Lazine?

Clinical trial data indicate that among the adverse reactions reported, somnolence (drowsiness) was the most frequently cited reason for patients discontinuing the medication. This reason for stopping the medication was generally reported with a low overall incidence rate.


Q: What is the difference between Lazine and a placebo in studies?

In official clinical trials, Lazine demonstrated a statistically significant benefit in relieving symptoms when compared to an inactive placebo. Studies showed a measurable difference from placebo in reducing symptoms for conditions like seasonal allergic rhinitis, perennial allergic rhinitis, and chronic idiopathic urticaria (hives).


Q: Does Lazine have a generic version available?

Yes, the U.S. Food and Drug Administration (FDA) has officially granted approval for generic versions of Lazine. Generic formulations of levocetirizine dihydrochloride are available for both the tablets and the oral solution.


Q: What happens if I forget to take my Lazine?

Standard patient information regarding a missed dose indicates that if the lapse is noticed soon, the dose may be taken. However, if it is nearly time for the next scheduled dose, the missed dose is usually skipped. Dosing recommendations caution against taking two doses at once.


Q: Can Lazine cause weight gain or loss?

Official regulatory adverse reaction reports observed an increase in weight (weight increased) as a less common reaction in clinical trials, occurring in a small percentage of subjects (0.5%). This change in weight has also been noted in postmarketing safety surveillance reports.


Q: Does Lazine interact with common pain relievers like ibuprofen?

Regulatory drug interaction summaries indicate that there is no known clinically significant interaction between Lazine (levocetirizine) and common non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen.


Q: Can people with high blood pressure use Lazine?

Official prescribing information does not list pre-existing high blood pressure (hypertension) as an absolute reason to avoid the drug. However, hypertension has been reported as a rare adverse effect during postmarketing surveillance.


Q: Is Lazine recommended during pregnancy?

Official labeling advises consulting a healthcare professional before use during pregnancy. The drug was historically classified as a Pregnancy Category B, meaning that while animal studies did not show risk to the fetus, adequate human studies supporting use are limited.


Q: Does Lazine affect birth control pills?

There are no known clinically significant drug interactions between Lazine and oral contraceptives (birth control pills) noted in major regulatory interaction summaries.


Q: Are there any special blood tests needed while on Lazine?

Official prescribing information indicates that no specific or routine blood tests are required solely to monitor the medication itself. Dose adjustment is required if a patient has reduced kidney function, which highlights the importance of kidney clearance for this medication.


Q: What is the risk of dependence or addiction with Lazine?

Lazine is not classified as a controlled substance in the United States. This classification indicates a low potential for abuse. However, a specific regulatory warning notes that a rare adverse reaction of intense itching (pruritus) has occurred upon stopping the medication after long-term use, which can indicate a physical rebound effect.


Q: What is the typical timeframe before Lazine reaches its full effect?

Regulatory pharmacological information indicates that the drug concentration reaches a steady state in the body, which is the consistent level needed for maximum benefit, typically after two days of once-daily dosing.


Q: Can Lazine be crushed or split in half?

Yes, the 5 mg film-coated tablet formulation of Lazine is officially scored (breakable). The scoring allows the tablet to be split, which is intended to facilitate an accurate lower dose when required.


Q: Is Lazine considered a controlled substance?

No, Lazine (levocetirizine dihydrochloride) is not classified as a controlled substance. This designation means it is not regulated under the Controlled Substances Act (CSA) in the United States.


Q: Does Lazine interact with vitamins or herbal supplements?

Official warnings note that Lazine is known to interact with other Central Nervous System (CNS) depressants. Due to the potential for interactions, consultation with a healthcare professional regarding the use of vitamins or herbal supplements is important, especially those known to cause drowsiness.


Q: What is the shelf life of Lazine tablets?

The tablets are generally stable and are regulated to be stored at controlled room temperature, typically between 20 C to 25 C (68 F to 77 F). The specific expiration date, or shelf life, for any particular product lot is determined by the manufacturer and is indicated on the final packaging.


Q: Can Lazine be taken with antacids?

Regulatory drug interaction summaries indicate that there is no known clinically significant interaction between Lazine (levocetirizine) and common antacids. The official prescribing information does not contain a specific warning about separating the dose from antacids.

How should Lazine be stored and disposed of?

How to Store and Dispose of Lazine

Lazine (Levocetirizine Dihydrochloride) must be stored and handled according to specific conditions defined in regulatory labeling to maintain stability and effectiveness.


Official Storage Requirements

Condition Requirement
Temperature Store at Controlled Room Temperature, typically 20 C to 25 C (68 F to 77 F).
Protection Keep the medicine out of excessive heat and away from moisture.
Container Keep the container tightly closed in the original packaging.
Restriction The oral solution formulation must not be frozen.
Safety Store Lazine out of the sight and reach of children.

Disposal Instructions

Expired or unused Lazine must be disposed of properly. Do not flush the medicine down the toilet or pour it into the sink, as this is discouraged by official guidance. The preferred method is to utilize a drug take-back program. If this is unavailable, the product may be mixed with an undesirable substance (like dirt or coffee grounds) and sealed in a container before discarding in the household trash, following local regulations.

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

Available in countries:

Equivalent of Lazine found in:

A-Z Index: