Allelock

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Allelock

Method of action: Antiallergic, Ophthalmologicals

Treatment option:

Medically reviewed

Marina Burgos

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 Allelock

Quick Facts

Property Description
Active ingredient Olopatadine hydrochloride
Form Oral Tablet (primarily 2.5 mg and 5 mg strengths)
Pharmacological class Selective H1 Antagonist and Mast Cell Stabilizer
Common use Anti-allergic agent for systemic relief
Origin Synthetic tricyclic compound

What is Allelock and What is its Composition?

Allelock is a pharmaceutical product primarily available as an oral tablet and formulated around the active ingredient Olopatadine hydrochloride. This substance is a highly specific, synthetic tricyclic compound recognized globally for its anti-allergic properties. As a single-ingredient product, Allelock's efficacy is derived solely from Olopatadine. Allelock tablets, marketed by Kyowa Hakko Kogyo Co., Ltd. in Japan, represent a key oral formulation of this compound, which is also prepared as ophthalmic solutions (eye drops) and nasal sprays under other trade names. The oral formulations are typically presented in strengths such as 2.5 mg and 5 mg.

Pharmacological Class and Differentiation

Allelock is defined by its dual pharmacological class: it is both a selective histamine H1 receptor antagonist and a powerful mast cell stabilizer. This molecule features a combined mechanism that effectively interrupts the allergic cascade at two points. Unlike many older compounds used for allergy relief, Olopatadine is clinically categorized as a non-sedating type of H1 antagonist. This feature makes it an option for patients seeking relief from systemic allergy symptoms without the common sedating effects often associated with first-generation antihistamines.

General Purpose and Unique Positioning

The general purpose of Allelock is to function as a systemic anti-allergic agent dedicated to suppressing the body’s overreaction to allergens, thereby mitigating the resulting physical discomfort. Its positioning as an oral tablet contrasts with its common use in the United States, where Olopatadine is best known in its topical ophthalmic form. Allelock offers broad relief by addressing the underlying biological events that generate allergy-related symptoms, making it particularly useful for systemic conditions where general body symptoms require management.

What side effects are possible with Allelock?

Possible Side Effects and Safety Information

The safety profile of Allelock, which contains Olopatadine hydrochloride (Oral), is formally documented by regulatory authorities, with adverse reactions classified by frequency and system organ class. The safety profile highlights effects linked to the drug's systemic action as a histamine antagonist.


Frequency-Classified Adverse Reactions

Adverse reactions are grouped according to their expected frequency of occurrence, as established in regulatory documents:

Classification Examples of Effects
Common (1 in 100 to 1 in 10 patients) Headache, Fatigue, Dysgeusia (altered or bitter taste).
Uncommon (1 in 1,000 to 1 in 100 patients) Dizziness, Hypoaesthesia (reduced sensation), Contact Dermatitis, Dry skin.
Not Known (Cannot be estimated from data) Somnolence (sleepiness), Hypersensitivity reactions, Nausea, Vomiting, Abnormal Hepatic Function.

Safety Considerations and Restrictions

Official labeling addresses specific safety patterns, particularly those involving the central nervous system (CNS) and certain patient populations. Due to the potential for systemic effects such as somnolence and impaired mental alertness, caution is formally required against engaging in hazardous activities, including driving or operating machinery.

High-level safety notes exist for specific populations. Use of the medicine is not recommended during pregnancy or lactation based on reproductive toxicity and excretion into milk observed in animal studies. Caution is also advised in patients with severe renal impairment, as drug exposure may be significantly increased, altering the pharmacokinetics of the medicine.

Overdose and Emergency Response

The regulatory documentation for Allelock (olopatadine) indicates that specific data regarding human overdose following accidental or deliberate ingestion are generally unavailable. The official overdose profile is therefore derived from the expected effects of excessive systemic exposure to an H1-antagonist, leading to documented expectations for clinical presentation.

Overdose Manifestations Mandated Emergency Actions
Adults: Expected manifestation includes drowsiness. Seek medical help right away.
Children: May initially present with agitation and restlessness before the onset of drowsiness. Contact a Poison Control Center immediately.

The official labeling requires that immediate medical attention be sought upon any suspicion of overdose or excessive ingestion. This instruction is mandatory to ensure patient safety and is required regardless of the initial signs.

Management of an olopatadine overdose is strictly limited to regulatory guidance, which emphasizes supportive and symptomatic treatment. The patient must be subjected to appropriate monitoring in a clinical setting to manage any developing symptoms. The prescribing information reviewed does not document the existence of a specific pharmacological antidote for this overdose scenario. The need to seek help immediately is required by regulatory authorities.

Therapeutic Uses of Allelock

What Allelock Treats: Main Uses and Benefits

Allelock is commonly used across conditions presenting with acute or recurrent allergic episodes, relevant in contexts where short-term symptomatic assistance is needed. It helps address symptoms related to systemic imbalance, providing support that helps ease the overall symptom burden. Olopatadine is used to help with symptoms related to allergic conditions.

This therapeutic domain is applied across areas where additional symptomatic support is needed, and is used for managing the discomfort of seasonal and perennial allergic rhinitis, hives (urticaria), and pruritus associated with specific skin diseases.

“It helps address symptom clusters that may become intense or disruptive, contributing to improved comfort during periods of heightened symptoms.”


Quick Fact: Relief for Allergic Discomfort

Symptom Domain Conditions Supported Benefit Focus
Nasal Manifestations Allergic Rhinitis (Seasonal/Perennial) Is relevant for easing sneezing, runny nose, and nasal congestion.
Cutaneous Symptoms Urticaria and Pruritic Skin Diseases Is applied in addressing body itching (pruritus) and outbreaks of hives.

The supportive relief assists with maintaining functional stability when symptoms interfere with routine activities, helping patients cope more steadily with difficult episodes.

Regulatory References

  1. Olopatadine Nasal Spray: MedlinePlus Drug Information

Eligibility and Restrictions for Use

Allelock (olopatadine hydrochloride) eligibility is determined by specific regulatory criteria regarding age, physiological state, and pre-existing conditions.

Contraindicated Populations

Use of Allelock is contraindicated (must not be used) if a patient has a known hypersensitivity or allergy to olopatadine hydrochloride or any other component of the product.

Eligibility and Restricted Use

Population Group Eligibility Status (Oral Formulation)
Adults and Adolescents Generally eligible.
Children ge 7 years Eligible (Tablets/Granules).
Children 2 to <7 years Eligible (Granules formulation only).
Infants and Children <2 years Use not established due to insufficient clinical data.

Pregnancy and Breastfeeding:

  • Pregnancy: The medicine should be used only if the potential benefit to the mother is determined to outweigh the potential risk to the fetus.
  • Lactation: Use is generally not recommended. If treatment is deemed essential, breastfeeding must be discontinued.

Conditions Requiring Caution:

Patients with impaired renal function or hepatic dysfunction require careful administration due to the potential for altered drug levels or aggravation of the existing condition. The medicine must also be used with caution in elderly patients, who may require a lower starting dose.

What should I know about interactions with other medicines?

Allelock Interactions with other medicines and products

This section describes the formally documented interaction patterns of the active ingredient Olopatadine (Allelock) based strictly on information found in official government regulatory sources, maintaining a neutral, descriptive, label-based perspective.


Documented Interaction Profile

Interaction Type Interacting Substances/Classes Official Outcome Status in Regulatory Labels
Pharmacodynamic Central Nervous System (CNS) Depressants Additive reduction in alertness and impairment of CNS performance. Use with Caution
Substance Alcohol Enhanced CNS depressant effects (e.g., increased drowsiness). Avoid Concurrent Use
Pharmacokinetic CYP Enzyme Inhibitors/Inducers No clinically significant interaction requiring mandatory restriction. No Mandatory Restriction

Official Interaction Statements

The primary official interaction statement concerns a pharmacodynamic risk when Allelock is co-administered with substances that affect the central nervous system. Regulatory documents advise caution when using Allelock alongside other CNS Depressants due to the potential for additive impairment of CNS performance and alertness. This additive effect is also the basis for the specific restriction regarding Alcohol, where concurrent use should be avoided to prevent enhanced drowsiness and dizziness. Furthermore, regulatory information does not describe any clinically significant pharmacokinetic interactions involving cytochrome P450 enzymes that necessitate a mandatory dose adjustment or restriction for the oral tablet form. No restrictions are formally documented regarding separation from food or specific herbal products.

Mechanism of Action

Allelock's active ingredient, olopatadine, operates through a dual-action pharmacodynamic mechanism that modulates biological systems involved in heightened immune and inflammatory responses. The drug primarily exerts its effect via two distinct mechanistic domains: receptor antagonism and mediator modulation.


Selective Histamine H1 Receptor Antagonism

Allelock functions as a selective inverse agonist and antagonist at the histamine H1 receptor. This interaction blocks the binding site of the endogenous inflammatory mediator, histamine, thereby preventing the subsequent activation of intracellular signaling cascades, which typically involve the release of IP3 and DAG. The resulting physiological consequence is a reduction in the cellular excitability level induced by excessive histamine activity.


Inhibitory Modulation of Inflammatory Mediators

Beyond receptor antagonism, Allelock engages mechanisms that regulate dysregulated cellular processes by inhibiting the production and release of key inflammatory lipid mediators from various cell types, including mast cells and eosinophils. This action specifically suppresses the formation of pro-inflammatory eicosanoids such as leukotrienes and thromboxane within the arachidonic acid cascade. This modifies downstream signaling, resulting in an attenuation of mediator release and a decline in pathway activity within targeted inflammatory systems.

Dosage and Administration Information

How to Use Allelock: Official Administration Guidelines

The administration of Allelock (olopatadine hydrochloride) follows specific instructions which define the dose, frequency, and conditions for use.

Official Dosing and Administration

Allelock is available in several oral forms, including standard tablets and Oral Dissolving (OD) tablets at strengths such as 2.5 mg and 5 mg. The medicine is administered orally and is used according to a fixed schedule rather than on an as-needed basis.

Administration Detail Standardized Instructions
Standard Adult Dose 5 mg of olopatadine hydrochloride at a time.
Frequency Twice daily (b.i.d.).
Timing Administered once in the morning and once before bedtime.
Duration of Course For seasonal allergic conditions, use typically continues until the end of the season is reached.

Population-Specific and Procedural Rules

Standard guidelines include specific instructions for certain patient groups and the mechanics of taking the dose:

  • Pediatric Dosing: Children 7 years of age and older follow the adult dose of 5 mg twice daily. For children aged 2 to under 7, the prescribed dose is 2.5 mg twice daily, typically using the granule formulation.
  • Older Adults: The dosage may be adjusted according to age and symptoms; administration typically begins cautiously at a low dose.
  • Missed Dose: If a morning dose is missed and noticed before noon, it may be taken as soon as possible. Otherwise, the dose is skipped, and the protocol specifies that a patient should never take two doses simultaneously to compensate.
  • OD Tablets: The oral dissolving tablets can be swallowed whole with water or allowed to dissolve completely in the mouth with saliva.

These instructions constitute the standardized protocol for the proper administration of Allelock.

Recent Clinical Evidence

Allelock: Recent Clinical Evidence

Overview of Clinical Trials

Research investigating Allelock (Olopatadine hydrochloride) primarily focuses on its use in allergic conditions such as allergic rhinitis and chronic urticaria. Studies utilized randomized, double-blind, placebo-controlled trial designs to evaluate the effects on symptoms and overall safety profile in adult and adolescent populations.

Efficacy Findings

Clinical trials have examined the change in standardized symptom scores. For allergic rhinitis, studies assessed the change in Total Nasal Symptom Scores (TNSS), including sneezing, nasal discharge, and nasal congestion, showing statistically significant improvements relative to placebo. For dermatological conditions, research investigated the change in the severity of pruritus (itching) and skin lesions.

Secondary assessments also focused on the impact on related factors, such as the use of rescue medication and the effect on sleep disturbance associated with nighttime itching, with some participants reporting lower nocturnal activity.

Safety and Tolerability

Allelock has been widely studied for its safety profile across multiple trial phases. In large-scale clinical trials and post-marketing surveillance, the incidence of adverse events (AEs) was generally low.

  • Common Adverse Events (AEs): The most frequently reported adverse effects included somnolence (sleepiness), fatigue, and mild gastrointestinal symptoms (e.g., dyspepsia). The incidence of somnolence, while observed, is generally lower than with first-generation antihistamines.
  • Serious Adverse Events (SAEs): Serious adverse events, including clinically significant hepatic function disorders (liver enzyme increases or jaundice), were reported as rare occurrences in post-marketing data. Study investigators monitored participants closely for all potential drug-related risks.

Frequently Asked Questions (FAQ)

Common questions about Allelock (FAQ)


Q: Does Allelock have a 'black box warning' or special safety statement described by the FDA?

According to the official US labeling, Allelock includes a comprehensive section detailing specific Warnings and Precautions related to its use. However, the oral formulation is not described as having a 'black box warning,' which is the FDA’s most serious form of safety alert. Full safety documentation is available in the official labels and should be reviewed.


Q: Is Allelock generally considered a short-term or long-term treatment?

Regulatory guidelines provide specific duration instructions for certain uses, such as continuing treatment for seasonal conditions until the end of the season. Official documents do not typically specify a general maximum duration of use for chronic conditions. Extended use of the medicine is typically determined by a prescribing healthcare professional based on clinical assessment.


Q: Is it safe to take Allelock alongside common over-the-counter pain relievers?

Official drug information advises caution when Allelock is used with any other substance that may cause an additive reduction in alertness. This warning is due to the potential for the combined effects to increase drowsiness or impair mental performance. Awareness of the ingredients in over-the-counter (OTC) medicines, especially those with sedating effects, is relevant when considering concurrent use.


Q: What should a patient know if they are currently taking multiple prescription medications with Allelock?

Official documents highlight a primary safety concern regarding interactions with Central Nervous System (CNS) depressants, which can cause increased drowsiness. Beyond CNS-acting drugs, regulatory information notes that interactions involving specific liver enzymes (CYP) do not necessitate mandatory restrictions or dose adjustments for the oral form.


Q: Is it common to experience certain side effects when first starting Allelock?

Studies and official patient information indicate that some people may experience common side effects, such as fatigue or dry mouth, which can be more noticeable during the first days of therapy. Patient information suggests that these initial effects may lessen as the body adjusts to the medicine with continued use.


Q: What kind of monitoring might be required for someone using Allelock long-term?

Official post-marketing surveillance data includes rare reports of abnormal hepatic function, meaning changes in liver enzyme levels. For individuals using Allelock for an extended duration, a healthcare provider may determine if occasional monitoring of liver function tests is appropriate.


Q: What official information is available regarding stopping the use of Allelock?

Clinical trial summaries generally indicate that studies did not report specific symptoms or a rebound effect upon the abrupt cessation of treatment. The need to continue use until a specific clinical endpoint is reached is often emphasized, suggesting discontinuation is determined by the treating physician.


Q: Is it normal if I don't feel any immediate change after starting Allelock?

According to official information, Allelock is administered on a fixed, consistent schedule (e.g., twice daily) rather than as a fast-acting medicine for immediate, as-needed relief. Its full therapeutic effect is intended to be achieved and maintained through regular, sustained use.


Q: How quickly can a person expect Allelock to start having an effect?

Clinical pharmacology data provided in regulatory documents describes how quickly the medicine is absorbed into the bloodstream. The time to reach maximum concentration in the body after oral administration is typically noted as being between 1.5 and 3.5 hours.


Q: Is Allelock only available by prescription?

Regulatory bodies have classified the oral formulation of Allelock as a prescription-only medicine. This designation means it requires authorization and oversight from a qualified healthcare provider to be dispensed.


Q: How is Allelock described in terms of its potential for dependence or misuse?

Based on regulatory scheduling decisions, Allelock is not classified as a controlled substance by government health authorities. Official information does not describe any formal potential for abuse or dependence associated with the use of this medicine.


Q: Is there a generic version of Allelock available, and what is the difference?

Regulatory documents confirm that the active ingredient, Olopatadine, has received approval for use in multiple generic formulations. Generic and brand-name versions contain the same active ingredient and meet the same strict quality and effectiveness standards required by regulators.


Q: Is Allelock described as affecting blood pressure or heart rate?

Official safety data categorizes all observed adverse events by body system. While common cardiac effects are not noted, the full safety documentation often includes rare reports of cardiovascular effects such as palpitations or tachycardia (rapid heart rate).

How should Allelock be stored and disposed of?

How to Store and Dispose of Allelock?

The storage and disposal of Allelock (olopatadine hydrochloride oral tablets) must align strictly with regulatory guidelines to maintain its stability.

Storage Requirements

Allelock must be stored at Controlled Room Temperature, defined as 20 C to 25 C (68 F to 77 F). The product must be protected from excessive moisture and kept in its original container, which should be tightly closed. Do not use the tablets if the container's inner seal is broken or missing. As with all medications, Allelock must be stored out of the sight and reach of children.

Disposal Instructions

Unused or expired Allelock should be discarded using authorized methods. The preferred disposal option is via an official community drug take-back program. If a take-back program is unavailable, the medication should be mixed with an undesirable substance (such as used coffee grounds) and placed in a sealed bag before being disposed of in the household trash.

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

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