Usage
This combination medication is prescribed for the temporary relief of symptoms associated with the common cold, the flu, allergies, hay fever, and other upper respiratory allergies, such as:
- Cough
- Runny nose
- Sneezing
- Itching of the nose or throat
- Itchy, watery eyes
- Nasal congestion
Pharmacological Classification:
This drug is a combination of:
- Antihistamine (Chlorpheniramine Maleate)
- Cough suppressant (Dextromethorphan Hydrobromide)
- Decongestant (Phenylephrine)
- Cooling agent (Menthol)
Mechanism of Action:
- Chlorpheniramine maleate: Blocks the action of histamine, a chemical mediator responsible for allergic symptoms.
- Dextromethorphan hydrobromide: Suppresses the cough reflex by acting on the cough center in the brain.
- Phenylephrine: Constricts blood vessels in the nasal passages, reducing swelling and congestion.
- Menthol: Provides a cooling sensation, soothing irritated throat tissues.
Alternate Names
There are no widely recognized alternate names for this specific four-ingredient combination. However, each individual ingredient may be referred to by its chemical name or other synonyms. The combination is often described by listing the generic names of its components. Several brand names exist for various combinations of these ingredients.
How It Works
Pharmacodynamics:
- Chlorpheniramine: Reduces histamine-mediated responses such as sneezing, itching, rhinorrhea, and lacrimation. It has mild anticholinergic and sedative effects.
- Dextromethorphan: Elevates the cough threshold in the medulla oblongata without causing analgesia or respiratory depression at recommended doses.
- Phenylephrine: Produces vasoconstriction, primarily in the nasal mucosa, leading to decongestion. It has less pressor activity than other sympathomimetics.
- Menthol: Activates TRPM8 receptors, leading to a cooling sensation. It also has mild local anesthetic and anti-inflammatory effects.
Pharmacokinetics:
- Chlorpheniramine: Absorbed well orally. Metabolized extensively in the liver and excreted primarily in urine.
- Dextromethorphan: Well-absorbed orally. Extensively metabolized by the liver (CYP2D6), with some metabolites contributing to antitussive activity. Excreted in urine.
- Phenylephrine: Absorbed orally, but undergoes first-pass metabolism. Metabolized by monoamine oxidase (MAO) in the intestine and liver. Excreted in urine.
- Menthol: Absorbed readily through skin and mucous membranes. Metabolized in the liver and excreted in urine and bile.
Receptor Binding, Enzyme Inhibition, or Neurotransmitter Modulation:
- Chlorpheniramine: H1 receptor antagonist.
- Dextromethorphan: NMDA receptor antagonist (at high doses); sigma-1 receptor agonist; may inhibit serotonin reuptake.
- Phenylephrine: α1-adrenergic receptor agonist.
Elimination Pathways:
- Chlorpheniramine: Primarily renal excretion.
- Dextromethorphan: Renal excretion, after hepatic metabolism (CYP2D6).
- Phenylephrine: Renal excretion after MAO metabolism.
- Menthol: Hepatic metabolism, followed by renal and biliary excretion.
Dosage
Standard Dosage
Adults:
- Syrup: 10 mL every 4 to 6 hours, not to exceed 60 mL in 24 hours.
Children:
- 2 to 6 years: 2.5 mL every 4 to 6 hours, not to exceed 15 mL in 24 hours.
- 6 to 12 years: 5 mL every 4 to 6 hours, not to exceed 30 mL in 24 hours.
Pediatric Safety Considerations: Not recommended for children under 2 years of age. Use with caution in atopic children due to the potential for histamine release with dextromethorphan.
Special Cases:
- Elderly Patients: Start with lower doses and titrate cautiously due to potential for increased sensitivity.
- Patients with Renal Impairment: Dose adjustment may be necessary.
- Patients with Hepatic Dysfunction: Use with caution and consider dose reduction due to the extensive hepatic metabolism of the ingredients.
- Patients with Comorbid Conditions: Use with caution in patients with hypertension, diabetes mellitus, ischemic heart disease, hyperthyroidism, increased intraocular pressure, prostatic hypertrophy, asthma, or narrow-angle glaucoma.
Clinical Use Cases
The combination of Chlorpheniramine Maleate + Dextromethorphan Hydrobromide + Menthol + Phenylephrine is typically not used in clinical settings such as intubation, surgical procedures, mechanical ventilation, or the ICU. Its usage is generally limited to outpatient treatment of common cold and allergy symptoms.
Dosage Adjustments
Dose adjustments may be necessary based on patient response, age, and the presence of renal or hepatic impairment.
Side Effects
Common Side Effects:
- Drowsiness or dizziness
- Dry mouth, nose, or throat
- Nausea or vomiting
- Blurred vision
- Constipation
- Headache
- Nervousness or excitability (especially in children)
Rare but Serious Side Effects:
- Allergic reactions (e.g., hives, difficulty breathing, swelling)
- Seizures
- Hallucinations
- Rapid or irregular heartbeat
- Severe dizziness
Long-Term Effects:
Chronic complications are unlikely with short-term use. Prolonged use of phenylephrine can lead to rebound congestion.
Adverse Drug Reactions (ADR):
Serious ADRs are rare but may include hypersensitivity reactions, cardiac arrhythmias, and CNS effects like seizures.
Contraindications
- Hypersensitivity to any of the ingredients.
- Concurrent or recent use of MAO inhibitors (within 14 days).
- Severe hypertension or coronary artery disease.
- Narrow-angle glaucoma, urinary retention, or severe asthma.
Drug Interactions
- MAO inhibitors (e.g., selegiline, phenelzine): Hypertensive crisis.
- Other sympathomimetics (e.g., epinephrine, pseudoephedrine): Increased risk of cardiovascular effects.
- Beta-blockers and antihypertensives: Reduced efficacy.
- Alcohol and CNS depressants: Additive sedative effects.
- Antihistamines: Increased anticholinergic effects.
- Tricyclic antidepressants: Increased anticholinergic and sedative effects.
Pregnancy and Breastfeeding
Pregnancy Safety Category: C (Dextromethorphan and Phenylephrine); B (Chlorpheniramine).
- Not recommended during pregnancy unless the potential benefit outweighs the risk to the fetus.
- Use during the third trimester may cause reactions in newborns.
Breastfeeding:
- Dextromethorphan, phenylephrine, and chlorpheniramine may be excreted in breast milk.
- Not recommended during breastfeeding due to potential for adverse effects in infants.
Drug Profile Summary
- Mechanism of Action: Antihistamine, cough suppressant, decongestant, and cooling agent.
- Side Effects: Drowsiness, dry mouth, dizziness, nausea, constipation, blurred vision.
- Contraindications: Hypersensitivity, MAOI use, severe cardiovascular disease, narrow-angle glaucoma.
- Drug Interactions: MAOIs, sympathomimetics, beta-blockers, alcohol, CNS depressants.
- Pregnancy & Breastfeeding: Use with caution; not recommended unless benefits outweigh risks.
- Dosage: Adults: 10 mL every 4-6 hours (max 60 mL/day); Children (2-6 years): 2.5 mL every 4-6 hours (max 15 mL/day); Children (6-12 years): 5 mL every 4-6 hours (max 30 mL/day)
- Monitoring Parameters: Blood pressure, heart rate, respiratory rate, and mental status.
Popular Combinations
This combination itself is a popular formulation. Some preparations may also include guaifenesin (an expectorant) or other ingredients.
Precautions
- General Precautions: Screen for allergies, pre-existing medical conditions (especially cardiovascular, respiratory, and metabolic disorders), and concomitant medications.
- Pregnant Women: Avoid unless potential benefits outweigh risks.
- Breastfeeding Mothers: Avoid.
- Children & Elderly: Use with caution and dose adjustments may be required.
- Lifestyle Considerations: Avoid alcohol and operating machinery while taking this medication.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Chlorpheniramine Maleate + Dextromethorphan Hydrobromide + Menthol + Phenylephrine?
A: Adults: 10 mL every 4-6 hours, not to exceed 60 mL in 24 hours. Children (2-6 years): 2.5 mL every 4-6 hours, not to exceed 15 mL in 24 hours. Children (6-12 years): 5 mL every 4-6 hours, not to exceed 30 mL in 24 hours.
Q2: Can this combination be used in patients with hypertension?
A: Use with caution in patients with hypertension. Monitor blood pressure closely.
Q3: What are the common side effects?
A: Drowsiness, dry mouth, dizziness, blurred vision, constipation, nausea, and headache.
Q4: Can I take this medication while pregnant or breastfeeding?
A: It’s generally not recommended during pregnancy or breastfeeding. Consult your doctor for guidance.
Q5: Can I drink alcohol while taking this medication?
A: Avoid alcohol as it can exacerbate drowsiness and dizziness.
Q6: What should I do if I miss a dose?
A: Take the missed dose as soon as you remember. Skip it if it’s almost time for the next dose. Do not double the dose.
Q7: How long can I take this medication?
A: Do not use this medication for more than 7 days unless directed by a physician.
Q8: What should I do if my symptoms don’t improve after a week?
A: Consult your doctor if your symptoms don’t improve or worsen.
Q9: Can this medication interact with other medicines I’m taking?
A: Yes, it can interact with certain medications, including MAO inhibitors, other sympathomimetics, beta-blockers, alcohol, and some antidepressants. Inform your doctor about all other medications and supplements you’re taking.
Q10: What is the role of menthol in this combination?
A: Menthol provides a cooling and soothing effect on irritated throat tissues.
