Usage
- This combination medication is prescribed for the temporary relief of symptoms associated with the common cold, hay fever (allergic rhinitis), or other upper respiratory allergies. These symptoms include cough due to minor throat or bronchial irritation, runny nose, sneezing, itching of the nose or throat, itchy and watery eyes, and nasal congestion.
- Pharmacological Classification: This is a combination product containing an antitussive (dextromethorphan), a decongestant (phenylephrine), an antihistamine (triprolidine), and a topical anesthetic/counterirritant (menthol).
- Mechanism of Action: Dextromethorphan suppresses the cough reflex by acting on the cough center in the brain. Phenylephrine reduces nasal congestion by constricting blood vessels in the nasal passages. Triprolidine relieves allergy symptoms by blocking the action of histamine. Menthol provides a cooling sensation and soothes minor throat irritation.
Alternate Names
While the generic name is Dextromethorphan Hydrobromide + Menthol + Phenylephrine + Triprolidine, there isn’t an accepted international nonproprietary name. It’s marketed under various brand names such as Tri -A-Koff DM, OOX-DM and Trilotuss-D. Other combinations of these ingredients are also available under different brand names.
How It Works
- Pharmacodynamics: Dextromethorphan acts centrally on the cough center in the medulla. Phenylephrine acts as an alpha-adrenergic agonist, causing vasoconstriction in the nasal mucosa. Triprolidine is a first-generation antihistamine that competitively antagonizes H1 receptors. Menthol activates TRPM8 receptors, leading to a cooling sensation.
- Pharmacokinetics: Absorption, metabolism, and elimination data for the combination product aren’t readily available. Individual components follow typical oral absorption patterns. Dextromethorphan is metabolized by the liver, primarily via CYP2D6. Phenylephrine undergoes both hepatic and extrahepatic metabolism. Triprolidine is also metabolized in the liver. All components are likely excreted primarily through the kidneys.
- Mode of Action: Dextromethorphan’s precise mechanism as an antitussive is unclear, though it is known to act centrally. Phenylephrine stimulates alpha-adrenergic receptors, causing vasoconstriction. Triprolidine competes with histamine for binding at H1 receptors, preventing histamine-mediated effects. Menthol acts on TRPM8 receptors, leading to its characteristic cooling sensation.
- Elimination Pathways: Primarily renal excretion with hepatic metabolism playing a role for all four components. CYP2D6 is significantly involved in dextromethorphan metabolism.
Dosage
Standard Dosage
Adults: 1 teaspoonful (5 ml) every 4 hours, not exceeding 4 teaspoonfuls (20 ml) in 24 hours.
Children:
- 6 to under 12 years: ½ teaspoonful (2.5 ml) every 4 hours, not exceeding 2 teaspoonfuls (10 ml) in 24 hours.
- 2 to under 6 years: Use with caution and only as directed by a physician.
- Under 2 years: Not recommended.
Special Cases:
- Elderly Patients: Use with caution. Start with the lowest recommended dose and monitor for adverse effects. Dose adjustments may be necessary.
- Patients with Renal Impairment: Use with caution. Dose modifications based on creatinine clearance may be necessary.
- Patients with Hepatic Dysfunction: Use with caution due to potential impaired metabolism. Dose adjustments may be necessary.
- Patients with Comorbid Conditions (e.g., diabetes, cardiovascular disease, hyperthyroidism, glaucoma, prostatic hypertrophy): Use with caution. The physician should assess the risk-benefit ratio. Dose adjustments may be necessary. Close monitoring is recommended.
Clinical Use Cases
This combination is not typically used in clinical settings such as intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations. Its primary indication is the symptomatic relief of cough and cold symptoms in outpatient settings.
Dosage Adjustments
Dose modifications should be considered based on renal or hepatic function, age, and other comorbidities.
Side Effects
Common Side Effects:
- Drowsiness
- Dizziness
- Nausea
- Dry mouth, nose, or throat
- Headache
- Nervousness or excitability (especially in children)
Rare but Serious Side Effects:
- Allergic reactions (rash, itching, swelling, severe dizziness, trouble breathing)
- Hallucinations
- Seizures
- Rapid or irregular heartbeat
Long-Term Effects:
Data regarding long-term effects are limited. Prolonged use of decongestants can lead to rebound congestion.
Adverse Drug Reactions (ADR):
Serious ADRs such as severe allergic reactions, hallucinations, or cardiac arrhythmias require immediate medical attention.
Contraindications
- Hypersensitivity to any of the active ingredients.
- Concurrent use of or within 14 days of using MAO inhibitors.
- Severe hypertension or severe coronary artery disease.
- Asthma attack (acute).
- Severe liver disease.
Drug Interactions
- MAO inhibitors (e.g., phenelzine, tranylcypromine): Risk of serious, potentially fatal interactions.
- Alcohol: Increased drowsiness and dizziness.
- Other CNS depressants (e.g., sedatives, tranquilizers, opioid pain medications): Additive CNS depression.
- Antihistamines applied to the skin (e.g., diphenhydramine cream): Increased risk of anticholinergic effects.
- Beta-blockers (e.g., metoprolol): Potential for hypertension.
- Tricyclic antidepressants (e.g., amitriptyline): Increased anticholinergic effects.
- Anticholinergics (e.g., atropine): Additive anticholinergic effects.
- Other sympathomimetics (e.g., pseudoephedrine): Additive effects and potential for cardiovascular complications.
Pregnancy and Breastfeeding
- Pregnancy Safety Category: Data are limited. Use only if clearly needed and under the guidance of a physician. Animal studies show potential risks, but human teratogenicity is not confirmed.
- Breastfeeding: Excretion in breast milk is unknown. Caution is advised. Potential for drowsiness and other adverse effects in the infant.
Drug Profile Summary
- Mechanism of Action: Antitussive, decongestant, antihistamine, and counterirritant combination.
- Side Effects: Drowsiness, dizziness, nausea, dry mouth, headache, nervousness, excitability.
- Contraindications: Hypersensitivity, MAOI use, severe hypertension/coronary artery disease, acute asthma attack, severe liver disease.
- Drug Interactions: MAOIs, alcohol, CNS depressants, antihistamines, beta-blockers, tricyclic antidepressants, other sympathomimetics.
- Pregnancy & Breastfeeding: Limited data. Use with caution if benefits outweigh risks.
- Dosage: Adults: 5 ml every 4 hours (max 20 ml/24h). Children (6-12 yrs): 2.5 ml every 4 hours (max 10 ml/24h).
- Monitoring Parameters: Blood pressure, heart rate, respiratory status, CNS effects.
Popular Combinations
While this combination itself is widely used, sometimes it’s combined with other medications for specific symptoms like fever (acetaminophen) or a productive cough (guaifenesin). However, these combinations should be used cautiously and under a doctor’s supervision due to the potential for additive effects and interactions.
Precautions
- General Precautions: Screen for allergies, metabolic disorders, organ dysfunction before prescribing. Assess risk/benefit in patients with comorbidities.
- Pregnant Women: Consult a doctor if necessary. Limited safety data in pregnancy.
- Breastfeeding Mothers: Consult a doctor before use due to unknown infant risk.
- Children & Elderly: Use with caution, monitor for side effects, and adjust dosage if necessary.
- Lifestyle Considerations: Avoid alcohol. May cause drowsiness, affecting driving and operating machinery.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Dextromethorphan Hydrobromide + Menthol + Phenylephrine + Triprolidine?
A: Adults: 5 ml every 4 hours (max 20 ml/24h). Children (6-12 yrs): 2.5 ml every 4 hours (max 10 ml/24h). Not recommended for children under 2 years.
Q2: Can this medication be used in patients with hypertension?
A: Use with caution in patients with mild to moderate hypertension, carefully monitoring blood pressure. Contraindicated in severe hypertension.
Q3: What are the most common side effects?
A: Drowsiness, dizziness, nausea, dry mouth/nose/throat, and headache.
Q4: Can this medication be used during pregnancy?
A: Limited human data. Animal studies suggest potential risks. Use only if clearly needed and after consultation with a physician.
Q5: What are the potential drug interactions I should be aware of?
A: MAO inhibitors, alcohol, CNS depressants, certain antidepressants, and other sympathomimetics.
Q6: Can I take this medication if I am breastfeeding?
A: Excretion in breast milk is unknown. Consult a physician before use.
Q7: What should I do if a patient experiences an allergic reaction?
A: Discontinue the medication immediately and provide appropriate medical care depending on the severity of the reaction.
Q8: Can this be used in children with asthma?
A: Use cautiously. Phenylephrine can worsen asthma symptoms in some cases. Avoid during acute asthma attacks.
Q9: Are there any dietary recommendations while taking this medication?
A: Stay well-hydrated to help loosen mucus and soothe irritation.
Q10: Can patients operate machinery or drive while taking this medication?
A: Use caution as it can cause drowsiness and impair cognitive function. Advise against driving or operating heavy machinery until individual response is assessed.
