Usage
Cetirizine + Dextromethorphan Hydrobromide is prescribed for the symptomatic relief of common cold and allergy symptoms, particularly when accompanied by a dry cough. It is indicated for conditions such as allergic rhinitis, the common cold, and other upper respiratory tract infections.
Alternate Names
There are no widely recognized alternate generic names for this specific combination. However, the individual components have various salt forms. Numerous brand names exist depending on the manufacturer and the region. Some common brand names mentioned in sources include Kozifed Plus.
How It Works
- Pharmacodynamics:
- Cetirizine: Antagonizes the effects of histamine at peripheral H1 receptors. It reduces vascular permeability, which minimizes edema and itching associated with allergic reactions.
- Dextromethorphan Hydrobromide: Acts centrally on the cough center in the medulla oblongata to elevate the threshold for coughing. It does not have analgesic or opioid-like properties at usual doses.
- Pharmacokinetics:
- Cetirizine: Well-absorbed orally. Peak plasma concentrations occur within 1 hour. It is not extensively metabolized by the liver and primarily excreted unchanged in the urine.
- Dextromethorphan Hydrobromide: Absorbed from the gastrointestinal tract. It undergoes extensive first-pass metabolism in the liver via CYP2D6. The major metabolite, dextrorphan, contributes to its antitussive effect. Primarily excreted in the urine as metabolites.
- Mode of Action:
- Cetirizine: Competitive inhibition of histamine at H1 receptors.
- Dextromethorphan Hydrobromide: The precise mechanism is unclear but thought to involve sigma-receptor binding and NMDA receptor antagonism.
- Elimination Pathways:
- Cetirizine: Primarily renal excretion.
- Dextromethorphan Hydrobromide: Hepatic metabolism followed by renal excretion of metabolites.
Dosage
Standard Dosage
Adults:
- Standard dose: Cetirizine 5-10 mg once daily combined with Dextromethorphan Hydrobromide 10-20 mg every 4-6 hours as needed for cough.
- Maximum daily dose of Dextromethorphan Hydrobromide should not exceed 120 mg.
Children:
- Pediatric dosing should be carefully determined based on the child’s weight and age. Consult specific pediatric guidelines. Generally, the combination is not recommended for children under 6.
- Pediatric safety considerations: Closely monitor children for side effects like drowsiness and excitability.
Special Cases:
- Elderly Patients: Start with lower doses and adjust according to response and tolerance.
- Patients with Renal Impairment: Dose reduction of Cetirizine may be required.
- Patients with Hepatic Dysfunction: Dose reduction of Dextromethorphan Hydrobromide may be necessary.
- Patients with Comorbid Conditions: Caution in patients with cardiovascular disease, diabetes, and prostatic hypertrophy.
Clinical Use Cases
The combination of Cetirizine and Dextromethorphan Hydrobromide is generally not indicated for use in settings like intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations. Its primary indication is symptomatic relief of cough and cold symptoms in an outpatient setting.
Dosage Adjustments
Dose adjustments may be required based on renal or hepatic function, patient response, and concomitant medications.
Side Effects
Common Side Effects
- Drowsiness
- Dry mouth
- Dizziness
- Nausea
- Fatigue
- Restlessness
Rare but Serious Side Effects
- Allergic reactions (rash, itching, swelling)
- Hallucinations
- Seizures
- Tachycardia
- Difficulty breathing
Long-Term Effects
Limited data on long-term effects. Chronic use of Dextromethorphan Hydrobromide at high doses can lead to neurotoxicity.
Adverse Drug Reactions (ADR)
Severe allergic reactions, cardiac arrhythmias, serotonin syndrome (with concurrent use of MAOIs or other serotonergic drugs).
Contraindications
- Hypersensitivity to cetirizine or dextromethorphan.
- Concurrent use of monoamine oxidase inhibitors (MAOIs).
- Asthma or conditions with excessive mucus production.
- Severe respiratory depression.
Drug Interactions
- Alcohol (increases CNS depression)
- CNS depressants (e.g., sedatives, tranquilizers)
- Anticholinergic drugs
- MAOIs (can cause serotonin syndrome)
- CYP2D6 inhibitors (may increase Dextromethorphan levels)
Pregnancy and Breastfeeding
- Pregnancy: Cetirizine is categorized as Pregnancy Category B, but use only if clearly needed. Dextromethorphan use during pregnancy should be carefully weighed against potential risks.
- Breastfeeding: Cetirizine is excreted in breast milk. The use of this combination while breastfeeding is generally not recommended.
Drug Profile Summary
- Mechanism of Action: Cetirizine: H1 receptor antagonist. Dextromethorphan: Centrally acting cough suppressant.
- Side Effects: Drowsiness, dry mouth, dizziness, nausea.
- Contraindications: Hypersensitivity, MAOI use.
- Drug Interactions: Alcohol, CNS depressants, MAOIs.
- Pregnancy & Breastfeeding: Use with caution if benefits outweigh risks.
- Dosage: Adults: Cetirizine 5-10 mg daily, Dextromethorphan 10-20 mg every 4-6 hours. Pediatric dosing should be weight-based.
- Monitoring Parameters: Respiratory rate, heart rate, mental status.
Popular Combinations
Sometimes combined with other medications like decongestants (e.g., phenylephrine, pseudoephedrine) or analgesics (e.g., paracetamol) for broader symptomatic relief of cold and flu symptoms.
Precautions
- Pre-existing medical conditions (e.g., renal/hepatic dysfunction, cardiovascular disease, diabetes).
- Pregnant/breastfeeding women: Assess potential risks vs. benefits.
- Children and elderly: Age-appropriate dosing and monitoring for side effects.
- Avoid driving or operating machinery if drowsiness occurs.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Cetirizine + Dextromethorphan Hydrobromide?
A: Adults: Cetirizine 5-10mg once daily, Dextromethorphan 10-20 mg every 4-6 hours. Pediatric dosing requires careful calculation according to age and weight.
Q2: Can I take this medication if I am pregnant or breastfeeding?
A: Consult your doctor before taking this medicine if you are pregnant or breastfeeding as there are potential risks to the developing fetus or infant.
Q3: What are the common side effects?
A: The most common side effects include drowsiness, dry mouth, dizziness, and nausea.
Q4: Can I drink alcohol while taking this medication?
A: Alcohol should be avoided as it can exacerbate the sedative effects of the medication.
Q5: What should I do if I miss a dose?
A: Take the missed dose as soon as you remember, unless it is close to the time for your next dose. Do not double the dose to catch up.
Q6: Are there any serious drug interactions I should be aware of?
A: Avoid taking this medication with MAOIs as it can lead to a serious reaction called serotonin syndrome. Inform your doctor about all medications you are taking, including over-the-counter drugs and supplements.
Q7: Can this medication be used in children?
A: While the combination can be used in children over the age of six, consult with a doctor.
Q8: How long can I take this medication?
A: This combination is intended for short-term symptomatic relief. Consult with a physician if symptoms persist beyond a week.
Q9: Can I drive or operate machinery while taking this medication?
A: Avoid such activities until you know how the medicine affects you, as drowsiness may occur.
