Cetirizine + Dextromethorphan Hydrobromide + Guaifenesin + Phenylephrine

Usage

This combination medication is primarily prescribed for the symptomatic relief of cough, nasal congestion, and other symptoms associated with the common cold, flu, and allergies. It is also used to treat productive and non-productive coughs related to upper respiratory tract infections (URTIs).

Pharmacological Classification: This is a combination product containing drugs from multiple classifications:

• Cetirizine: Antihistamine (second-generation)
• Dextromethorphan Hydrobromide: Antitussive (non-narcotic)
• Guaifenesin: Expectorant
• Phenylephrine: Decongestant (alpha-adrenergic agonist)

Mechanism of Action: Cetirizine acts by blocking histamine H1 receptors, reducing allergic symptoms like sneezing, runny nose, and itchy eyes. Dextromethorphan suppresses cough by affecting the cough center in the brain. Guaifenesin thins and loosens mucus, making it easier to cough up. Phenylephrine constricts blood vessels in the nasal passages, reducing nasal congestion.

Alternate Names

There is no single international non-proprietary name (INN) for this specific combination. The individual components have the following INNs: cetirizine, dextromethorphan, guaifenesin, and phenylephrine. Various brand names exist depending on the manufacturer and specific formulation, including Kozifed Plus and Active Junior Syrup (for a combination containing ambroxol along with the four main ingredients). Other brands may exist.

How It Works

Pharmacodynamics: Cetirizine competitively inhibits histamine binding at H1 receptors. Dextromethorphan acts centrally in the medulla to elevate the cough threshold. Guaifenesin increases respiratory tract fluid secretions, reducing mucus viscosity. Phenylephrine stimulates alpha-adrenergic receptors in the nasal mucosa, causing vasoconstriction.

Pharmacokinetics:

• Cetirizine: Absorbed orally, peak plasma concentration within 1 hour. Metabolized minimally, primarily excreted renally.
• Dextromethorphan: Well-absorbed orally. Extensively metabolized by the liver (CYP2D6), with some individuals being poor metabolizers. Excreted renally.
• Guaifenesin: Readily absorbed from the gastrointestinal tract. Metabolized in the liver and excreted renally.
• Phenylephrine: Poorly absorbed orally. Metabolized by monoamine oxidase in the intestinal wall and liver. Eliminated renally.

Mode of Action: Cetirizine exerts its effect through receptor antagonism. Dextromethorphan acts centrally. Guaifenesin acts by indirectly stimulating glands in the respiratory tract. Phenylephrine acts via receptor agonism.

Dosage

Standard Dosage

Adults:

The dosage varies significantly based on the formulation. For oral liquids, doses can range from 1 mL to 60 mL. For oral solids, the typical dosage is 2 tablets or caplets every 4 hours, with a maximum of 6 doses per day. It is crucial to consult the specific product information for detailed dosage instructions.

Children:

Dosages for children depend on age and formulation. Liquid doses are variable and should be determined according to the manufacturer’s instructions. For oral solids, some formulations are only recommended for children 12 years and older. Always consult product-specific guidelines for pediatric dosing.

Special Cases:

• Elderly Patients: Start with a lower dose and monitor for side effects.
• Patients with Renal Impairment: Dose reduction may be necessary.
• Patients with Hepatic Dysfunction: Dosage adjustments are typically required.
• Patients with Comorbid Conditions: Caution is advised in patients with hypertension, heart disease, diabetes, glaucoma, thyroid disorders, or prostatic hypertrophy. Individualized dosing and close monitoring are necessary.

Clinical Use Cases

The provided sources do not give specific dosages for these situations, as the medication is primarily for outpatient use in mild to moderate cases of cold and flu. Its usage in situations like intubation, surgical procedures, mechanical ventilation, ICU, or emergency situations is generally not indicated.

Dosage Adjustments

Dosage adjustments should be made based on patient-specific factors like age, weight, renal and hepatic function, and concomitant medications. Consultation with a physician is essential before adjusting the dose.

Side Effects

Common Side Effects

• Drowsiness
• Dizziness
• Dry mouth
• Nausea
• Headache
• Blurred vision
• Loss of appetite

Rare but Serious Side Effects

• Allergic reactions (rash, itching, swelling, difficulty breathing)
• Hallucinations
• Seizures
• Rapid heartbeat
• Confusion
• Loss of consciousness

Long-Term Effects

Chronic use can lead to tolerance to dextromethorphan and dependence.

Adverse Drug Reactions (ADR)

Serious ADRs require immediate discontinuation of the medication and medical intervention. These include severe allergic reactions, cardiac arrhythmias, serotonin syndrome (with MAOI interaction), and respiratory depression.

Contraindications

• Hypersensitivity to any component of the medication.
• Concurrent use or recent use (within 14 days) of Monoamine Oxidase Inhibitors (MAOIs).
• Severe respiratory depression.

Drug Interactions

• MAOIs: Can lead to hypertensive crisis and serotonin syndrome.
• Alcohol: Potentiates the sedative effects of the medication.
• Antihistamines, antidepressants, antifungals, antibiotics: Consult drug information resources for specific interactions.
• Other cough and cold medications: Avoid concurrent use due to overlapping ingredients.

Pregnancy and Breastfeeding

The safety of this combination during pregnancy and breastfeeding has not been fully established. Use only if clearly needed and after consulting a physician. Cetirizine is pregnancy category B. Phenylephrine is pregnancy category C. Dextromethorphan is generally considered low risk, but individual assessment is needed. All components can be excreted in breast milk, potentially affecting the infant.

Drug Profile Summary

• Mechanism of Action: Multifaceted action targeting different cold and flu symptoms. Cetirizine: H1 receptor antagonist. Dextromethorphan: Central cough suppressant. Guaifenesin: Expectorant. Phenylephrine: Decongestant.

• Side Effects: Drowsiness, dizziness, dry mouth, nausea, headache. Serious side effects: Allergic reactions, hallucinations, cardiac issues, serotonin syndrome.

• Contraindications: Hypersensitivity, concurrent or recent MAOI use, severe respiratory depression.

• Drug Interactions: MAOIs, alcohol, various medications.

• Pregnancy & Breastfeeding: Consult physician; potential risks to fetus and infant.

• Dosage: Highly variable based on formulation and age. Consult product information.

• Monitoring Parameters: Blood pressure, heart rate, respiratory rate, mental status, allergy symptoms.

Popular Combinations

This medication is already a combination product. Combining it with other drugs, especially other cough and cold remedies or those containing the same components, should be avoided or done under strict medical supervision.

Precautions

• Assess patient history for allergies, medical conditions, and concomitant medications.
• Exercise caution in specific populations (pregnant/breastfeeding women, children, elderly, those with renal/hepatic dysfunction).
• Advise against alcohol consumption, driving, and operating heavy machinery.

FAQs (Frequently Asked Questions)

Q1: What is the recommended dosage for Cetirizine + Dextromethorphan Hydrobromide + Guaifenesin + Phenylephrine?

A: The dosage varies considerably based on age and the specific product formulation (liquid, tablet, etc.). Always refer to the manufacturer’s instructions for precise dosing guidelines.

Q2: Can this combination be used in children?

A: Some formulations are appropriate for children, but the dosage and age limits vary. Consult product-specific information and seek pediatric advice when necessary.

Q3: What are the common side effects?

A: Common side effects include drowsiness, dizziness, dry mouth, nausea, and headache. More serious side effects can occur, so patients should be monitored.

Q4: What are the major drug interactions?

A: Avoid concomitant use with MAOIs and alcohol. Several drug interactions are possible, so careful review of concomitant medications is crucial.

Q5: Can pregnant or breastfeeding women use this combination?

A: The safety profile in pregnancy and breastfeeding is not definitively established. Use only if clearly needed and after consulting a physician.

Q6: What conditions does this medication treat?

A: It is primarily used to relieve cough, nasal congestion, and other symptoms associated with the common cold, flu, and allergies.

Q7: How should I adjust the dosage for patients with renal or hepatic impairment?

A: Consult a physician. Dose reductions are typically necessary for these patients.

Q8: What should I do if a patient experiences an allergic reaction?

A: Discontinue the medication immediately and provide appropriate medical care, including antihistamines, corticosteroids, and epinephrine if needed.

Q9: Can this combination be used for chronic cough?

A: It is primarily intended for short-term relief of cough associated with acute illnesses like colds and flu. For chronic cough, further investigation into the underlying cause is necessary.

Q10: Is it safe to operate machinery or drive after taking this medication?

A: Drowsiness and dizziness are potential side effects. Advise patients to avoid driving or operating machinery until they know how the medication affects them.