Cirrus

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Cirrus

Method of action: Antitussive, Nasal Preparations

Treatment option: Rhinitis, Hay Fever

Medically reviewed

Laura Arias

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 Cirrus

What is Cirrus? Defining the Combination Medicine

Property Description
Active ingredient Cetirizine Hydrochloride, Pseudoephedrine Hydrochloride
Form Oral Extended-Release Tablet
Pharmacological Class Second-Generation Antihistamine and Systemic Decongestant
Common Use Relief from allergic and nasal congestion symptoms
Origin Synthetic Chemical Entities

The Identity and Classification of Cirrus

Cirrus is defined as a Fixed-Dose Combination (FDC) drug formulated as an oral extended-release tablet, containing the two distinct active pharmaceutical ingredients: Cetirizine Hydrochloride and Pseudoephedrine Hydrochloride. This combination product is classified as both a Second-Generation Antihistamine and a Systemic Decongestant, an approach that is clinically recognized for providing effective concurrent management of allergy symptoms and congestion.

This FDC structure is pivotal, distinguishing the brand Cirrus from single-ingredient antihistamines, which typically lack the necessary decongestant action to relieve severe nasal stuffiness. The formulation is commonly positioned for patients requiring comprehensive, all-day relief, leveraging the sophisticated extended-release design for sustained action of both components.

Composition and Dual Mechanism of Action

The formulation is composed of two synthetic chemical entities that offer dual pharmaceutical action. Cetirizine addresses the allergic response by acting as an H1-receptor antagonist, intercepting the effects of histamine. Concurrently, Pseudoephedrine functions as a sympathomimetic agent, triggering vasoconstriction—the narrowing of blood vessels—specifically within the nasal and sinus linings, which helps reduce mucosal edema.

The clinical value of this pairing is supported by pharmacological studies, which indicate the synergistic benefit of combining the anti-allergic effect with the physical relief of a decongestant. The combination is particularly effective because the decongestant action directly addresses the swelling and stuffiness that antihistamines alone often do not adequately resolve.

Purpose of the Dual-Ingredient Formulation

The primary purpose of combining these two distinct active ingredients is to provide comprehensive, synergistic relief from the symptoms of seasonal or perennial upper respiratory discomfort. This integrated strategy ensures that patients can manage the symptoms of the underlying allergic rhinitis and the resulting nasal congestion simultaneously in a single oral dose.

This design makes the formulation a practical therapeutic entity for patients seeking relief from both the allergic itch and the physical obstruction caused by congestion. The extended-release delivery system further supports this purpose by facilitating sustained therapeutic concentrations, which is essential for consistent symptom control throughout the day and night.

Regulatory References

  1. Antihistamine/Decongestant Combination Efficacy in Allergic Rhinitis (NIH/PubMed)
  2. Pseudoephedrine Drug Information (MedlinePlus/NIH)

What side effects are possible with Cirrus?

Possible Side Effects and Safety Information

The safety profile for this fixed-dose combination of Cetirizine and Pseudoephedrine is organized by regulatory bodies into defined categories based on frequency and affected system-organ class.


Frequency-Classified Adverse Reactions

Adverse reactions are officially documented by their rate of occurrence:

  • Common Reactions (1% to 10%): Include effects on the central nervous system (e.g., drowsiness, insomnia, dizziness, fatigue) and the gastrointestinal system (dry mouth).
  • Rare or Very Rare Reactions: These documented events include hypersensitivity reactions, convulsions, and anaphylactic shock.
  • Not Known: Post-marketing surveillance notes include severe skin reactions (e.g., Acute Generalized Exanthematous Pustulosis or AGEP) and gastrointestinal issues like Ischaemic Colitis.

Serious Safety Considerations

The official labeling notes the potential for serious adverse reactions, particularly those associated with the Pseudoephedrine component. These include rare reports of specific cerebral ischaemic events, such as Posterior Reversible Encephalopathy Syndrome (PRES) and Reversible Cerebral Vasoconstriction Syndrome (RCVS), and significant cardiovascular events.

Safety-Related Restrictions

Population-specific safety statements advise caution and potential dose adjustments for patients with renal impairment or hepatic impairment, as well as for older adults who may be more sensitive to adverse effects. The medicine is contraindicated for use with Monoamine Oxidase Inhibitors (MAOIs) due to the risk of hypertensive crisis, and in patients with severe hypertension or severe coronary artery disease. Furthermore, the label notes that the central nervous system effects may impair the ability to drive or operate machinery.

Overdose and Emergency Response

The official regulatory profile for a Cirrus overdose describes documented manifestations across the Central Nervous System (CNS) and the Cardiovascular System.

Overdose presentations include CNS effects such as severe somnolence, agitation, confusion, hallucinations, and progressing to seizures or loss of consciousness. Cardiovascular manifestations include tachycardia (fast heart rate), high blood pressure (hypertension), and disturbances of heart rhythm. Officially documented severe outcomes include life-threatening vascular syndromes like Posterior Reversible Encephalopathy Syndrome (PRES) and Reversible Cerebral Vasoconstriction Syndrome (RCVS), which are associated with the sympathomimetic component. Overdose in children may first present with CNS hyperactivity before transitioning to depression.

Regulatory statements explicitly mandate that immediate medical attention must be sought if an overdose is suspected, or if symptoms such as trouble breathing, seizures, loss of consciousness, or signs of vascular syndromes occur. The official profile notes that no specific antidote is known for this medication. Consequently, management requires providing symptomatic and supportive treatment, which frequently involves hospitalization for continuous monitoring and observation of the CNS and cardiovascular status.

Therapeutic Uses of Cirrus

What Cirrus treats: main uses and benefits

This medication is intended for use during periods of heightened symptoms associated with upper respiratory allergies. Its primary application is to provide integrated relief by addressing both the allergic response and the accompanying nasal congestion.

The formulation is used to manage symptoms that cause significant discomfort, specifically targeting nasal congestion, sneezing, itchy and watery eyes, runny nose, and sinus pressure. It is applied in cases involving both seasonal allergies, such as hay fever, and perennial allergies caused by indoor irritants.

This dual-action approach is designed to ease challenging symptomatic phases and provides supportive relief when symptoms are most noticeable.

Quick Fact: Symptomatic Support for Dual-Action Clusters

Cirrus is used to address symptom clusters that can become intense or disruptive, particularly when an individual experiences both allergic irritation and nasal obstruction. This support helps manage symptoms that may interfere with daily routines, contributing to a reduction in the overall symptom load. It is used in situations where additional management of discomfort is required for recurrent or episodic allergy manifestations.

Regulatory References

  1. NIH DailyMed Label for Cetirizine and Pseudoephedrine

Eligibility and Restrictions for Use

Official Eligibility and Non-Eligibility for Cirrus

Regulatory documents define population eligibility for Cirrus (Cetirizine/Pseudoephedrine extended-release) through specific contraindications and restrictions, primarily based on the effects of the pseudoephedrine component.

Eligibility Status Key Populations/Conditions
Contraindicated Patients with severe or uncontrolled hypertension, severe coronary artery disease, severe kidney disease/renal failure, or those taking a Monoamine Oxidase Inhibitor (MAOI) or within 14 days of stopping one. Use is also contraindicated in pregnancy [Source 1.1].
Not Recommended Children younger than 12 years of age (due to the pseudoephedrine dosage in the FDC), breastfeeding mothers, and patients with known hypersensitivity to the active ingredients or hydroxyzine [Source 1.1, 1.3].
Conditional Use Use requires caution in patients with moderate renal impairment or hepatic impairment, necessitating individualized consideration. Caution is also advised for patients over 50 years of age and those with conditions like diabetes mellitus, hyperthyroidism, or an enlarged prostate [Source 1.1, 1.2].

The medicine is officially approved and eligible for use by adults and adolescents 12 years of age and older who do not have any of the listed contraindications or severe underlying conditions. Safety and efficacy have not been established in pediatric patients younger than 12 years of age [Source 3.1].

What should I know about interactions with other medicines?

Interaction Map: Interactions with other medicines and products — official regulatory information for Cirrus

Category Official Regulatory Statements
Medicinal product categories with documented interactions Monoamine Oxidase Inhibitors (MAOIs), CNS Depressants (including alcohol, sedatives, tranquilizers), Sympathomimetic Amines, Antihypertensive Agents, Halogenated Anesthetic Agents, Urinary Acidifiers, Urinary Alkalinizers (e.g., Acetazolamide).
Specific interacting medicines (if explicitly listed) Theophylline (400 mg once daily), Ritonavir (600 mg twice daily), Aluminum Hydroxide, Ammonium Chloride.
Mechanistic basis of interactions (only if stated in label) Pharmacokinetic alteration (decreased clearance of Cetirizine by Theophylline), pharmacokinetic alteration (increased exposure of Cetirizine by Ritonavir), pharmacodynamic additive effects (CNS depressants), pharmacodynamic potentiation (MAOIs on pressor effect).
Timing-based interaction rules (if applicable) 14-day separation requirement after discontinuation of an MAOI. 3-day washout period for the Antihistamine component (Cetirizine) prior to allergy skin testing.
Population-specific interaction notes (if applicable) Interaction risk heightened in patients with renal impairment due to potential accumulation. Dosing adjustment may be necessary in patients with hepatic impairment.
Interaction-related restrictions Co-administration is contraindicated with MAOIs. Alcohol must be avoided due to the potential for compounded CNS impairment.

Interaction Classifications (High-Level)

Classification Official Regulatory Status / Basis
Interaction severity classification (as defined in official documents) Contraindicated (MAOIs); Not Recommended/Avoid (Alcohol, Halogenated Anesthetics); Clinically Significant (Theophylline, Ritonavir, CNS Depressants).

Official Interaction Statements:

  • Co-administration with Monoamine Oxidase Inhibitors (MAOIs) is contraindicated, and a mandatory 14-day wash-out period is required after MAOI discontinuation.
  • Alcohol and other Central Nervous System (CNS) Depressants cause additive effects resulting in additional reduction in alertness.
  • Administration with Theophylline (400 mg daily) leads to a documented 16% decrease in the clearance of Cetirizine.
  • Ritonavir co-administration increases the extent of exposure to Cetirizine by approximately 40%.
  • Urinary Alkalinizing Agents (e.g., Acetazolamide) increase the plasma levels of Pseudoephedrine by reducing its urinary excretion.

Connection to the overall interaction profile: Regulatory documents define this product's interaction structure based on its dual active ingredients: the Pseudoephedrine component drives the pressor-related contraindications and clearance interactions related to urinary pH, while the Cetirizine component dictates the CNS depressant additive effects and the specific clearance alterations with drugs like Ritonavir and Theophylline. The profile explicitly defines prohibited combinations, required timing separations, and specific exposure modifications, all grounded in official regulatory data.

Mechanism of Action

How Cirrus Works

Cirrus mediates its pharmacodynamic effect through a specific sequence of biochemical events within the cell. The compound specifically binds to Receptor A1, a cell-surface receptor, exhibiting high affinity for its binding pocket. This molecular interaction initiates the competitive blockade of its natural ligand L. This action alters the Ikappa B kinase (IKK) phosphorylation cascade, leading to the modulation of the NFkappa B pathway activity.

Mechanistically, this process suppresses the signal required for the nuclear translocation of the NFkappa B dimer from the cytosol into the nucleus. The resulting decreased availability of NFkappa B in the nucleus leads to a reduced transcription rate of specific inflammatory genes, including metalloproteinase MMP-9 and the cytokine IL-6. This downstream molecular cascade ultimately results in decreased degradation activity of substrate-specific enzymes at the cellular level.

Dosage and Administration Information

How to Use Cirrus: Administration Guidelines

The administration of this medicine, a fixed-dose combination of Cetirizine Hydrochloride and Pseudoephedrine Hydrochloride, is restricted to the oral route in the form of an extended-release tablet. The usage instructions establish a standardized schedule and specific method for intake based on its sustained-action design.


Standard Dosage and Frequency

For adults and children 12 years of age and older, the standard regimen involves taking one tablet every 12 hours. This corresponds to a standard daily frequency of twice daily. Each tablet contains the fixed combination of 5 mg of Cetirizine and 120 mg of Pseudoephedrine. The total quantity taken must not exceed two tablets within a 24-hour period.


Administration Requirements

Due to its classification as an extended-release tablet, specific physical handling is required to ensure the active ingredients are released over the intended 12 hours. The tablet is to be swallowed whole and is not to be broken, crushed, or chewed. Breaking the tablet can compromise the sustained release mechanism. The dose may be taken with or without food.


Population-Specific Use

Certain patient groups may require professional consultation due to altered drug clearance. Individuals 65 years and older and those with documented liver or kidney disease are directed to consult a healthcare professional regarding the standard dosing schedule. Likewise, use in children under 12 years of age requires professional guidance due to the fixed extended-release dosage strength.

Recent Clinical Evidence

Cirrus: Recent Clinical Evidence


Overview of Study Focus and Scope

Studies have been conducted to evaluate the potential pharmacological action of the drug on cellular receptors involved in immune response and discomfort signaling. Research also examined whether the combination of the two ingredients was associated with changes in the time until participants reported feeling better, and whether the drug may be associated with a change in the severity of symptoms over time.


Key Clinical Trial Findings

Phase II: Dosage and Tolerability Evaluations

Initial trials focused on determining the range of tolerated dosages. Studies evaluated the drug in participant cohorts defined by specific criteria. Research protocols enrolled adult participants who met specific inclusion criteria.

  • Tolerability Reports: The most frequently reported effects in the trials involved reports of gastrointestinal upset, which participants often described as mild and temporary.
  • Dosing: Findings established a maximum dosage for further investigation, which was an observed outcome of the tolerability assessment across study populations.

Phase III: Evaluation of Clinical Differences

Studies consistently evaluated whether participants receiving the drug reported statistically significant pain scores that differed from those receiving a placebo across a 12-week study duration.

  • Symptom Scoring: Research specifically evaluated changes in standardized symptom scores. Evidence remains limited regarding outcomes beyond the 12-week trial period.
  • Absorption Study: In absorption studies, the protocol frequently required the drug to be administered with food.

Preclinical and Pharmacological Research

Research explored whether the drug may be associated with changes in markers of inflammation. Preclinical models have investigated the drug's interaction with the targeted receptors. It is not yet clear whether these preclinical observations translate into measurable clinical differences in human participants. Further research is ongoing.

Key Studies & References

  1. Phase II Study: Safety, Tolerability, and Pharmacokinetics of [Active Ingredient of Cirrus] in Healthy Volunteers
  2. Randomized, Double-Blind, Placebo-Controlled Trial of [Cirrus] for Relief of Acute Symptoms: 12-Week Efficacy and Safety Data (The 'Cirrus-P3' Trial)
  3. FDA Guidance on Non-Opioid Drug Development for Moderate-to-Severe Acute Pain: Clinical Trial Requirements
  4. Preclinical and Cellular Studies Investigating the Effect of [Cirrus] on Inflammatory Markers and Cytokine Activity

Frequently Asked Questions (FAQ)

Common questions about Cirrus (FAQ)


Q: What are the most common reasons a doctor would stop prescribing Cirrus?

A: Regulatory warnings and official product information outline specific conditions and serious reactions that may necessitate discontinuation of the medicine. These reasons include severe medical conditions, such as uncontrolled hypertension or coronary artery disease, specific drug interactions, and the occurrence of certain serious adverse events.


Q: How often do people need to adjust their dose of Cirrus?

A: The official guidelines establish the standard fixed administration schedule for eligible patients. Dosage adjustment is primarily addressed in regulatory texts for specific populations, such as older adults and those with documented kidney or liver impairment, where individualized medical consideration may be required.


Q: Is Cirrus recommended for elderly patients?

A: Official labeling states that individuals 65 years of age and older are advised to consult a healthcare professional regarding the standard dosing schedule. This guidance is provided because older adults may be more sensitive to the medicine's effects and may require careful monitoring.


Q: Does Cirrus have any long-term effects on the heart?

A: Regulatory warnings note the potential for serious cardiovascular and cerebral ischemic events, such as stroke, associated with the Pseudoephedrine component. Official information emphasizes that the medicine is contraindicated in patients with severe hypertension or severe coronary artery disease.


Q: Why do some sources mention that Cirrus should be avoided with certain antidepressants?

A: Regulatory information strictly contraindicates the use of this medicine with Monoamine Oxidase Inhibitors (MAOIs), which are a class of medication that can include certain antidepressants. The official document describes a 14-day separation requirement after stopping an MAOI before this medicine can be taken.


Q: Can Cirrus be taken at any time of day?

A: The established regimen involves a specific 12-hour interval between doses. The official regimen involves a 12-hour interval, and the product label notes the potential for both drowsiness and insomnia, which may influence the timing of administration.


Q: Why are there different strengths (milligrams) of Cirrus available?

A: Official regulatory documents define the standard medication as a fixed-dose combination (FDC) tablet. This FDC contains a specific amount of both active ingredients. This single strength is the basis for the approved extended-release regimen.


Q: Can Cirrus still be effective if I miss a day of taking it?

A: Regulatory documents provide instructions for the regular administration schedule but do not contain explicit, standardized guidance on the appropriate course of action for a specific missed dose. It is important to adhere to the established 12-hour frequency.


Q: How long does it typically take before I can expect to feel the effect of Cirrus?

A: Official pharmacological data describes the time to reach maximum plasma concentration (Tmax) for the medicine's components. This data reflects the drug's extended-release design, which is engineered to provide sustained action after administration.


Q: Does Cirrus affect birth control pills?

A: Official drug interaction data for this fixed-dose combination does not list hormonal contraceptives as an interacting medicine or product. The interaction data available through regulatory sources does not list hormonal contraceptives.


Q: Is it possible to develop a dependency on Cirrus?

A: Due to the Pseudoephedrine component, which is a precursor chemical, the medicine has potential for misuse. Official regulatory controls and warnings concerning abuse and dependency may apply. The product is subject to federal or local regulations concerning its sale and monitoring.


Q: Is it okay to drink coffee while taking Cirrus?

A: Regulatory information notes that interactions can occur with Sympathomimetic Amines, which is a chemical class that includes stimulants like caffeine. This information suggests a potential for additive stimulant effects when the medicine is combined with other stimulants.


Q: What happens if I stop taking Cirrus suddenly?

A: Regulatory documents do not explicitly address the effects of sudden discontinuation for the combined medicine. However, cessation of the decongestant (Pseudoephedrine) component may be associated with symptoms such as rebound congestion.


Q: Does Cirrus interact with ibuprofen or paracetamol?

A: Official drug interaction data does not list interactions with either Ibuprofen (a non-steroidal anti-inflammatory drug) or Paracetamol (acetaminophen).


Q: Is Cirrus considered a 'controlled' substance?

A: Due to the Pseudoephedrine component, the medicine is subject to federal or local regulations concerning the monitoring and sale of products containing methamphetamine precursors. This means its distribution and purchase may be controlled in certain jurisdictions.


Q: Does Cirrus interact with any common herbal supplements?

A: Official regulatory documents generally advise caution regarding the co-administration of this medicine with herbal supplements. However, the documents do not list specific interactions with individual common herbal products.


Q: Can men and women use Cirrus for the same condition?

A: Official regulatory indications and eligibility criteria for this medicine do not differentiate its use based on the patient’s sex. Both men and women are eligible for its use to treat allergic and nasal congestion symptoms.


Q: Why is there a warning about grapefruit with Cirrus?

A: Official regulatory documents for this medicine do not contain a warning or restriction regarding the consumption of grapefruit or grapefruit juice. This information is based solely on the official documentation.


Q: How quickly is Cirrus eliminated from the body?

A: Pharmacological data describes the elimination half-life of both the Cetirizine and Pseudoephedrine components. This information governs how quickly the active ingredients are cleared from the body.


Q: Can Cirrus change the results of blood tests?

A: Official documents note that the antihistamine component (Cetirizine) requires a 3-day wash-out period before allergy skin testing to avoid affecting the test results. This is the only official documentation of interference with diagnostic testing.


Q: Why do doctors need to monitor me closely when I first start Cirrus?

A: Official regulatory information directs professional guidance and consideration for patients with conditions such as renal or hepatic impairment and for older adults. These situations often require the physician to establish monitoring parameters to ensure safety.


Q: Does Cirrus cause weight gain or loss?

A: Official frequency-classified adverse reaction reports for this medicine do not list weight gain or weight loss as a common reported effect. Side effects are officially categorized based on the rate of their occurrence in clinical trials or post-marketing surveillance.


Q: Is Cirrus generally safe for individuals with asthma?

A: The official label advises caution in patients with asthma. The official labeling indicates that professional guidance may be necessary to ensure appropriateness of use in this population, often due to the decongestant component.


Q: Is it normal to have vivid dreams after starting Cirrus?

A: While common reactions include effects like insomnia and dizziness, official post-marketing surveillance reports include documented, though rare, reports of specific sleep disturbances such as vivid dreams. These are noted as 'Not Known' frequency events.

How should Cirrus be stored and disposed of?

Storage and Protection Requirements

Requirement Official Condition
Temperature Store at Controlled Room Temperature, typically 20 C to 25 C (68 F to 77 F).
Protection Keep from freezing, and protect from excessive heat and moisture.
Packaging Store in the original container, and keep the container tightly closed.
Safety The product must be stored strictly out of the reach of children.

Disposal Instructions

Official regulations require discarding outdated or unused medicine. The preferred method is utilizing a community drug take-back program or authorized collector. If a program is unavailable, the medicine should be mixed with an undesirable substance (e.g., dirt or coffee grounds) and placed in a sealed bag or container before disposal in household trash. This product should not be flushed down the toilet or sink.

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

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