Dextromethorphan Hydrobromide + Pseudoephedrine + Triprolidine

Usage

This combination medication is used to relieve symptoms associated with the common cold, flu, and allergies, such as cough, nasal congestion, runny nose, sneezing, itching of the nose and throat, and itchy or watery eyes. It is specifically formulated to address dry coughs.

• Pharmacological Classification: This is a combination product containing:

  • Dextromethorphan Hydrobromide: Antitussive (Cough suppressant)
  • Pseudoephedrine: Nasal Decongestant (Sympathomimetic amine)
  • Triprolidine: Antihistamine (H1 receptor antagonist)

• Mechanism of Action:

  • Dextromethorphan works centrally in the medulla oblongata to suppress the cough reflex.
  • Pseudoephedrine constricts blood vessels in the nasal passages, reducing swelling and congestion.
  • Triprolidine blocks the effects of histamine, relieving allergy symptoms.

Alternate Names

This combination medication is often referred to as a decongestant-antihistamine-antitussive combination. Brand names include Actifed Dry Coughs, Trifed, Actihist-Co Syrup, and Benylin Dual Action Dry Syrup.

How It Works

• Pharmacodynamics:

  • Dextromethorphan acts on sigma receptors in the cough center of the brain, suppressing the cough reflex. It has no analgesic or addictive properties.
  • Pseudoephedrine activates alpha-adrenergic receptors, causing vasoconstriction in the nasal mucosa. This reduces nasal congestion.
  • Triprolidine competitively inhibits H1 histamine receptors, reducing the effects of histamine release, which include sneezing, runny nose, and itching.

• Pharmacokinetics:

  • All three components are readily absorbed from the gastrointestinal tract.
  • Dextromethorphan is metabolized by the liver, primarily via CYP2D6, to its active metabolite, dextrorphan.
  • Pseudoephedrine is partially metabolized in the liver and excreted primarily by the kidneys.
  • Triprolidine is extensively metabolized in the liver and excreted in urine.

• Elimination Pathways: Primarily renal excretion for pseudoephedrine and triprolidine, and hepatic metabolism followed by renal excretion for dextromethorphan.

Dosage

Standard Dosage

Adults:

10 mL (2 teaspoonfuls) every 4-6 hours, up to a maximum of 40 mL in 24 hours.

Children:

Not recommended for children under 12 years of age. For children 12 years and older, the adult dose is typically used. For younger children, consult a physician. Some sources suggest the following for younger children, but only with physician oversight:

• 6-12 years: 5 ml (1 teaspoonful) four times a day every 4 hours.
• 2-5 years: 2.5 ml four times a day every 4 hours.
• Under 2 years: Not recommended.

Special Cases:

• Elderly Patients: Start with a lower dose and monitor closely for adverse effects.
• Patients with Renal Impairment: Use with caution; dosage adjustments may be necessary.
• Patients with Hepatic Dysfunction: Use with caution; dosage adjustments may be necessary.
• Patients with Comorbid Conditions: Use with caution in patients with hypertension, diabetes, heart disease, hyperthyroidism, glaucoma, and prostatic hyperplasia.

Clinical Use Cases This medication is not typically used in clinical settings such as intubation, surgical procedures, mechanical ventilation, or emergency situations.

Dosage Adjustments Adjustments may be required based on individual patient characteristics and response.

Side Effects

Common Side Effects:

Drowsiness, dizziness, dry mouth, nausea, vomiting, constipation, difficulty sleeping, restlessness, and anxiety.

Rare but Serious Side Effects:

Allergic reactions (rash, itching, swelling), hallucinations, confusion, rapid or irregular heartbeat, difficulty breathing, and seizures.

Long-Term Effects:

Tolerance to the cough-suppressing effects of dextromethorphan may develop with prolonged use.

Adverse Drug Reactions (ADR): Serotonin syndrome (when combined with other serotonergic drugs), and hypertensive crisis (especially with MAOIs).

Contraindications

• Hypersensitivity to any component.
• Severe hypertension or coronary artery disease.
• Asthma or other respiratory conditions with excessive secretions.
• Concurrent or recent use of MAOIs (within 14 days).
• Patients at risk of developing respiratory failure.

Drug Interactions

• Alcohol, other CNS depressants (sedatives, tranquilizers, opioids), and MAOIs can interact with this combination.
• CYP2D6 inhibitors (e.g., fluoxetine, paroxetine, quinidine) can increase dextromethorphan levels.
• Pseudoephedrine can interact with antihypertensive medications.

Pregnancy and Breastfeeding

Use with caution during pregnancy and breastfeeding. Safety has not been established. Pseudoephedrine and triprolidine can be excreted in breast milk.

Drug Profile Summary

• Mechanism of Action: Decongestant, antihistamine, and antitussive.
• Side Effects: Drowsiness, dizziness, dry mouth, nausea, and constipation. Serious side effects are rare.
• Contraindications: Hypersensitivity, severe cardiovascular disease, MAOI use, and respiratory compromise.
• Drug Interactions: Alcohol, CNS depressants, MAOIs, CYP2D6 inhibitors, and antihypertensives.
• Pregnancy & Breastfeeding: Use with caution; safety not established.
• Dosage: Adults: 10 mL every 4-6 hours (max 40 mL/24h). Not recommended for children under 12.
• Monitoring Parameters: Blood pressure, heart rate, respiratory status, and mental status.

Popular Combinations

This combination itself is commonly used. The inclusion of guaifenesin is sometimes seen, to add an expectorant effect.

Precautions

Standard precautions for each individual component should be observed. Screen for allergies, pre-existing conditions, and concomitant medications. Caution in special populations (elderly, pregnant/breastfeeding women, children). Avoid alcohol. May impair driving or operating machinery.

FAQs (Frequently Asked Questions)

Q1: What is the recommended dosage for Dextromethorphan Hydrobromide + Pseudoephedrine + Triprolidine?

A: Adults and children 12 years and older: 10 mL every 4-6 hours, up to four times a day. Not recommended for children under 12 years of age.

Q2: Can this combination be used in patients with hypertension?

A: Use with caution in patients with well-controlled hypertension. Avoid in patients with severe or uncontrolled hypertension.

Q3: Can this combination be used during pregnancy?

A: Use with caution during pregnancy as safety has not been established. Consult a physician.

Q4: What are the common side effects?

A: Drowsiness, dizziness, dry mouth, nausea, and constipation.

Q5: Are there any serious drug interactions?

A: Yes. Avoid concurrent use with MAOIs. Use caution with alcohol, CNS depressants, and certain antidepressants.

Q6: Can this medication be used for a wet cough?

A: This medication is primarily indicated for dry cough. If the cough is productive (wet), alternative medications may be more appropriate.

Q7: Can I operate machinery after taking this medication?

A: Use caution, as this medication may cause drowsiness or dizziness. Avoid operating machinery if impaired.

Q8: How long can I take this medication?

A: Consult a physician. Generally, it is used for short-term symptom relief. Prolonged use may lead to tolerance to the cough-suppressing effects.

Q9: What should I do if I experience an allergic reaction?

A: Discontinue use immediately and seek medical attention.