Chlorpheniramine Maleate + Dextromethorphan Hydrobromide + Paracetamol + Phenylephrine

Usage

This combination medication is primarily prescribed for the temporary relief of symptoms associated with the common cold and flu, including nasal congestion, cough, fever, headache, minor aches and pains, sore throat, sneezing, and itchy/watery eyes.

Pharmacological Classification: This drug is a combination product and includes the following classes:

• Analgesic and Antipyretic: Paracetamol
• Antihistamine: Chlorpheniramine Maleate
• Cough Suppressant (Antitussive): Dextromethorphan Hydrobromide
• Decongestant: Phenylephrine Hydrochloride

Mechanism of Action: This combination targets multiple symptoms simultaneously. Paracetamol reduces fever and pain. Chlorpheniramine maleate provides relief from allergy symptoms like sneezing and runny nose. Dextromethorphan hydrobromide suppresses cough. Phenylephrine hydrochloride relieves nasal congestion.

Alternate Names

While there isn’t one single international non-proprietary name for this specific four-component combination, the individual components are recognized globally. The combination itself is often referred to as a “cold and flu” medication. Brand names vary depending on the region and manufacturer and may include “Dimetapp Cough Cold & Flu Night Relief,” “Panadol Flu Strength,” and others.

How It Works

Pharmacodynamics:

• Paracetamol: Exerts analgesic and antipyretic effects by inhibiting prostaglandin synthesis in the central nervous system.
• Chlorpheniramine Maleate: A first-generation antihistamine that competes with histamine for H1-receptor sites, reducing allergic symptoms.
• Dextromethorphan Hydrobromide: Suppresses the cough reflex by acting centrally on the cough center in the medulla oblongata.
• Phenylephrine Hydrochloride: Stimulates alpha-adrenergic receptors in the nasal mucosa, causing vasoconstriction and reducing nasal congestion.

Pharmacokinetics:

All four components are readily absorbed from the gastrointestinal tract. Paracetamol is extensively metabolized by the liver and eliminated primarily by the kidneys. Chlorpheniramine maleate is also metabolized by the liver, with a longer half-life. Dextromethorphan is metabolized primarily in the liver by CYP2D6 and eliminated in the urine. Phenylephrine undergoes both hepatic and intestinal metabolism.

Mode of Action:

• Paracetamol: Inhibition of cyclooxygenase (COX) enzymes, primarily COX-2 in the CNS, reducing prostaglandin production.
• Chlorpheniramine Maleate: Competitive antagonism of histamine at H1 receptors.
• Dextromethorphan Hydrobromide: Non-opioid mechanism of action on sigma receptors and NMDA receptor antagonism in the cough center.
• Phenylephrine Hydrochloride: Agonism at alpha-1 adrenergic receptors.

Elimination Pathways: Predominantly renal excretion for paracetamol, chlorpheniramine (as metabolites), and dextromethorphan (as metabolites). Hepatic and intestinal metabolism contribute to the elimination of phenylephrine.

Dosage

Standard Dosage

Adults: The standard dose for adults (12 years and older) varies based on the specific formulation. Typically, it involves two capsules or tablets every 4-6 hours as needed, not to exceed the maximum daily dose. Always refer to specific product labeling.

Children: Dosing for children below 12 years varies considerably with age and weight, and some formulations are not recommended for children under 6 years. Strict adherence to product-specific pediatric dosing guidelines is essential.

Special Cases:

• Elderly Patients: Dose adjustments may be necessary due to age-related decline in hepatic and renal function. Start with the lower end of the dosing range.
• Patients with Renal Impairment: Dose reduction is often required. Consult specific product information or clinical resources for guidance.
• Patients with Hepatic Dysfunction: Paracetamol dosage, in particular, needs careful adjustment due to the risk of hepatotoxicity.
• Patients with Comorbid Conditions: Caution is advised in patients with cardiovascular disease, hypertension, diabetes, glaucoma, thyroid disorders, prostatic hypertrophy, and other conditions.

Clinical Use Cases

This combination is not typically indicated for use in clinical settings like intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations. Its primary use is for symptomatic relief of common cold and flu.

Dosage Adjustments

Dosage adjustments must be made based on patient factors like renal and hepatic function, age, and coexisting medical conditions. Always consult specific product information or clinical resources.

Side Effects

Common Side Effects:

Drowsiness, dry mouth, nausea, dizziness, constipation, blurred vision, headache, and excitability.

Rare but Serious Side Effects:

Allergic reactions (rash, itching, swelling), hepatotoxicity (with paracetamol overdose), cardiac arrhythmias, severe drowsiness, and confusion.

Long-Term Effects:

Chronic use of this combination is not recommended due to the potential for adverse effects, particularly with paracetamol and phenylephrine.

Adverse Drug Reactions (ADR):

Any signs of hypersensitivity, severe liver dysfunction, or cardiac arrhythmias require immediate medical attention.

Contraindications

• Hypersensitivity to any component of the medication.
• Severe hypertension or coronary artery disease.
• Narrow-angle glaucoma.
• Monoamine oxidase inhibitor (MAOI) therapy (current or within 14 days).
• Severe respiratory insufficiency.
• Certain metabolic disorders and genetic polymorphisms.

Drug Interactions

• MAOIs: Concomitant use can lead to serious adverse reactions, including serotonin syndrome.
• Alcohol, Sedatives, Tranquilizers: Increased drowsiness and impaired cognitive function.
• Antidepressants: Potential for drug interactions, particularly with tricyclic antidepressants and SSRIs.
• Antihypertensives: Phenylephrine may counteract their effects.
• Other Cold and Flu Medications: Avoid concurrent use to prevent overdose of individual components.

Pregnancy and Breastfeeding

The safety of this combination during pregnancy and breastfeeding has not been fully established. Consult product information or clinical guidelines for recommendations.

Drug Profile Summary

• Mechanism of Action: See above.
• Side Effects: See above.
• Contraindications: See above.
• Drug Interactions: See above.
• Pregnancy & Breastfeeding: Consult specific product information or clinical guidelines.
• Dosage: See above.
• Monitoring Parameters: Liver function tests (especially with paracetamol), blood pressure (with phenylephrine), and respiratory status.

Popular Combinations

This combination itself is already a popular mixture of commonly used medications. Adding additional medications without clear clinical justification is generally discouraged.

Precautions

• Assess for pre-existing medical conditions, allergies, and concomitant medications.
• Avoid alcohol and other CNS depressants.
• Use cautiously in patients with liver or kidney disease.
• Elderly patients may be more susceptible to adverse effects.
• Do not exceed recommended dosages.

FAQs (Frequently Asked Questions)

Q1: What is the recommended dosage for Chlorpheniramine Maleate + Dextromethorphan Hydrobromide + Paracetamol + Phenylephrine?

A: The dosage varies according to age, specific product formulation, and individual patient characteristics. Refer to the detailed dosage section above.

Q2: Can this combination be used in children?

A: Some formulations are approved for pediatric use, but age and weight restrictions apply. Consult specific product information or pediatric dosing guidelines.

Q3: What are the most common side effects?

A: Drowsiness, dry mouth, nausea, dizziness, and constipation are among the most frequent side effects.

Q4: Can I take this medication if I am pregnant or breastfeeding?

A: Consult your physician before taking this combination during pregnancy or breastfeeding, as safety has not been fully established.

Q5: What are the serious drug interactions to be aware of?

A: Avoid concurrent use with MAOIs, alcohol, sedatives, and other CNS depressants. Consult your doctor before using it with antidepressants or antihypertensives.

Q6: Can I take this with other over-the-counter cold medications?

A: It’s generally not recommended to mix this combination with other OTC cold and flu medications as it may result in exceeding safe doses of individual components.

Q7: What should I do if I miss a dose?

A: Take the missed dose as soon as you remember, unless it’s almost time for the next dose. Do not double the dose.

Q8: What are the signs of an overdose?

A: Nausea, vomiting, dizziness, confusion, and liver damage are potential signs of overdose, especially involving paracetamol. Seek immediate medical attention if an overdose is suspected.

Q9: Can this medication cure the common cold or flu?

A: No, it does not cure the underlying viral infection but helps manage the symptoms.

Q10: How long should I take this medication?

A: Use it for the shortest period necessary to relieve symptoms, typically not exceeding a few days, unless advised otherwise by a doctor.