Dextromethorphan Hydrobromide + Triprolidine

Usage

• Medical Conditions: This combination medication is prescribed for the temporary relief of symptoms associated with the common cold, hay fever, or other upper respiratory allergies. These symptoms include dry cough, runny nose, sneezing, itching of the nose or throat, and itchy, watery eyes.
• Pharmacological Classification: Antitussive (Dextromethorphan) and Antihistamine (Triprolidine).
• Mechanism of Action: Dextromethorphan suppresses the cough reflex by acting on the cough center in the brain. Triprolidine works by blocking the action of histamine, a substance released by the body during an allergic reaction that causes allergy symptoms.

Alternate Names

• No widely recognized alternate names for the combination exist. Individual components may be known by their chemical names.
• Brand Names: Many brand names exist depending on the region and specific formulation. Examples include (but are not limited to) Actifed, Robitussin DM.

How It Works

• Pharmacodynamics: Dextromethorphan acts centrally on the cough center in the medulla to suppress the cough reflex. It does not possess analgesic or addictive properties like opioids, despite structural similarities. Triprolidine is a competitive histamine H1-receptor antagonist, reducing symptoms mediated by histamine release. It also has anticholinergic properties, which contribute to drying effects on secretions.
• Pharmacokinetics: Both drugs are absorbed orally. Dextromethorphan is extensively metabolized in the liver, primarily by CYP2D6, and excreted in the urine. Triprolidine is also metabolized in the liver and excreted in the urine.
• Mode of Action/Receptor Binding/Enzyme Inhibition/Neurotransmitter Modulation: Dextromethorphan acts on sigma-1 receptors and NMDA receptors in the brain. It also inhibits serotonin reuptake to some extent. Triprolidine competitively binds to H1 histamine receptors, blocking histamine action.
• Elimination Pathways: Primarily hepatic metabolism followed by renal excretion for both drugs.

Dosage

Standard Dosage

Adults: Typically, 10-20 mg of Dextromethorphan and 2.5 mg of Triprolidine are administered every 4-6 hours as needed. Formulations may vary, so always refer to the specific product labeling.

Children: Dosing is weight and age-dependent. Specific pediatric formulations exist, and it’s crucial to follow the recommended guidelines on the product labeling. Generally, this combination is not recommended for children under 6 years old, and some formulations are not appropriate for children under 12 years old.

Special Cases:

• Elderly Patients: Start with a lower dose and monitor closely due to potential increased sensitivity to side effects.
• Patients with Renal Impairment: Caution is advised, and dose adjustment may be necessary, especially in moderate to severe impairment.
• Patients with Hepatic Dysfunction: Caution is advised due to hepatic metabolism of both drugs. Dosage adjustments may be needed.
• Patients with Comorbid Conditions: Use with caution in patients with asthma, COPD, glaucoma, cardiovascular disease, prostatic hypertrophy, diabetes, or hyperthyroidism. Consult product labeling or specialist advice as needed.

Clinical Use Cases

This combination is typically used for symptomatic relief in outpatient settings and is generally not indicated for the following:

• Intubation
• Surgical Procedures
• Mechanical Ventilation
• Intensive Care Unit (ICU) Use
• Emergency Situations

Dosage Adjustments

Dose modifications are based on patient-specific factors such as age, renal/hepatic function, and other medical conditions. Consult the specific product labeling for details or seek expert consultation.

Side Effects

Common Side Effects:

• Drowsiness
• Dizziness
• Dry mouth, nose, and throat
• Nausea
• Headache
• Restlessness or excitability (especially in children)
• Blurred Vision

Rare but Serious Side Effects:

• Allergic reactions (rash, itching, swelling, difficulty breathing)
• Seizures
• Hallucinations
• Fast heartbeat
• Severe drowsiness

Long-Term Effects:

No specific long-term effects have been consistently reported. However, chronic use of any medication should be carefully evaluated.

Adverse Drug Reactions (ADR): Any of the rare and serious side effects listed above would constitute an ADR requiring immediate medical attention.

Contraindications

• Hypersensitivity to dextromethorphan or triprolidine.
• Concurrent use of monoamine oxidase inhibitors (MAOIs) or within 14 days of discontinuing MAOIs.
• Severe respiratory depression.
• Asthma exacerbation.

Drug Interactions

• MAOIs: Risk of serotonin syndrome.
• Alcohol: Increased sedation and CNS depression.
• Other CNS depressants (e.g., sedatives, tranquilizers): Additive sedative effects.
• Anticholinergic drugs: Additive anticholinergic effects.

Pregnancy and Breastfeeding

• Pregnancy Safety Category: Generally considered Category C. Use only if the potential benefit justifies the potential risk to the fetus.
• Breastfeeding: Both drugs can pass into breast milk. Use cautiously.

Drug Profile Summary

• Mechanism of Action: Dextromethorphan: Central cough suppressant; Triprolidine: H1-receptor antagonist, anticholinergic.
• Side Effects: Drowsiness, dizziness, dry mouth, nausea, headache. Rarely: allergic reactions, seizures, hallucinations.
• Contraindications: Hypersensitivity, concurrent MAOI use, severe respiratory depression.
• Drug Interactions: MAOIs, alcohol, CNS depressants, anticholinergics.
• Pregnancy & Breastfeeding: Use with caution. Consult a physician.
• Dosage: Refer to specific product labeling. Adults: Dextromethorphan 10-20 mg and Triprolidine 2.5 mg every 4-6 hours.
• Monitoring Parameters: Respiratory status, mental status, and any signs of adverse reactions.

Popular Combinations

• Sometimes combined with a decongestant like pseudoephedrine or phenylephrine to address nasal congestion.

Precautions

• General Precautions: Assess for allergies, pre-existing medical conditions, and concomitant medications.
• Specific Populations: See “Dosage - Special Cases.”
• Lifestyle Considerations: Avoid alcohol and activities requiring alertness.

FAQs

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

A: Refer to specific product labeling as formulations vary. Adults typically take 10-20 mg of dextromethorphan and 2.5 mg of triprolidine every 4-6 hours. Pediatric dosing is age and weight-dependent and should be determined based on product-specific recommendations.

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

A: Use cautiously in asthmatic patients, especially during acute attacks. It may thicken secretions, making it difficult to clear airways.

Q3: What are the significant drug interactions?

A: Avoid co-administration with MAOIs. Be cautious with alcohol, other CNS depressants, and anticholinergic drugs.

Q4: Can pregnant or breastfeeding women take this medication?

A: Consult a physician before use during pregnancy or breastfeeding as the risks and benefits should be assessed individually.

Q5: What are the common side effects?

A: Common side effects include drowsiness, dizziness, dry mouth/nose/throat, nausea, and headache.

Q6: What should I do if a patient experiences an allergic reaction?

A: Discontinue use immediately and seek emergency medical attention.

Q7: Can this combination be used for chronic cough?

A: It is intended for temporary relief of cough associated with the common cold or allergies. For persistent or chronic cough, consult a physician to determine the underlying cause.

Q8: Can this medication impair driving ability?

A: Yes, this combination can cause drowsiness and dizziness. Patients should avoid operating machinery or driving until they know how the medication affects them.

Q9: Is this medication habit-forming?

A: Dextromethorphan at therapeutic doses is not typically habit-forming, unlike opioid cough suppressants. However, misuse and abuse are possible at higher doses.

Q10: Are there any dietary restrictions while taking this medication?

A: While no specific dietary restrictions are universally required, staying well-hydrated is generally recommended. Avoid grapefruit juice as it might interact with dextromethorphan.