Usage
This combination medication is primarily prescribed for the symptomatic relief of influenza and common cold symptoms, including runny or stuffy nose, sneezing, itching, watery eyes, headache, fever, body aches, and sinus congestion. It is particularly useful for patients at high risk of developing complications from these illnesses.
Pharmacological Classification: This is a combination product containing:
- Amantadine: Antiviral, Antiparkinsonian
- Chlorpheniramine Maleate: Antihistamine (first-generation)
- Paracetamol (Acetaminophen): Analgesic, Antipyretic
- Phenylephrine: Decongestant (alpha-adrenergic agonist)
Mechanism of Action: This combination targets multiple pathways to address various symptoms:
- Amantadine inhibits influenza A virus replication and affects dopamine and acetylcholine neurotransmission.
- Chlorpheniramine competes with histamine for H1-receptor sites, mitigating allergic symptoms.
- Paracetamol inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin synthesis, which lowers fever and pain.
- Phenylephrine stimulates alpha-adrenergic receptors, causing vasoconstriction in the nasal mucosa, which relieves congestion.
Alternate Names
This combination is often referred to as Amantadine-Chlorpheniramine-Paracetamol-Phenylephrine. Several brand names exist depending on the region and manufacturer (e.g., Flublast). Rosel, available in Mexico, contains amantadine, chlorpheniramine, and paracetamol.
How It Works
Pharmacodynamics: The combined effects of the individual components provide comprehensive symptom relief. Amantadine targets the influenza A virus, chlorpheniramine addresses allergic responses, paracetamol reduces fever and pain, and phenylephrine alleviates nasal congestion.
Pharmacokinetics:
- Amantadine: Well-absorbed orally, primarily renally excreted unchanged.
- Chlorpheniramine: Hepatically metabolized, renally excreted.
- Paracetamol: Extensively hepatically metabolized, renally excreted.
- Phenylephrine: Metabolized by monoamine oxidase (MAO) in the gastrointestinal tract and liver.
Mode of Action: Each component acts on specific targets: Amantadine blocks the M2 protein of the influenza A virus; Chlorpheniramine antagonizes H1 histamine receptors; Paracetamol inhibits COX enzymes; and Phenylephrine activates alpha-adrenergic receptors.
Elimination Pathways: Primarily renal excretion for amantadine and hepatic metabolism followed by renal excretion for the other components.
Dosage
Standard Dosage
Adults: A common dosage is one tablet containing 500 mg paracetamol, 2 mg chlorpheniramine maleate, 5 mg phenylephrine hydrochloride, and 50 mg amantadine every four to six hours as needed, not exceeding four tablets daily.
Children: Generally not recommended for children under 12. Older children’s dosages should be determined by a physician based on weight and age, with careful monitoring for side effects.
Special Cases:
- Elderly Patients: Dose adjustments may be necessary due to age-related declines in renal and hepatic function. Start with a lower dose and titrate as needed.
- Patients with Renal Impairment: Dosage modification is required; consult specific guidelines.
- Patients with Hepatic Dysfunction: Dosage modification is required; consult specific guidelines.
- Patients with Comorbid Conditions: Careful consideration is needed for patients with cardiovascular disease, glaucoma, hypertension, or other relevant conditions.
Clinical Use Cases
Dosage in specific medical settings should be determined on a case-by-case basis by the treating physician, considering patient-specific factors. This combination is typically not the primary treatment in scenarios like intubation, surgical procedures, mechanical ventilation, or ICU use.
Dosage Adjustments
Adjustments are based on renal/hepatic function, other medical conditions, and potential drug interactions. Always consider individual patient characteristics.
Side Effects
Common Side Effects: Drowsiness, dizziness, dry mouth, blurred vision, constipation, nausea, nervousness, insomnia.
Rare but Serious Side Effects: Allergic reactions (rash, itching, swelling, difficulty breathing), hepatotoxicity, cardiac arrhythmias, hallucinations, seizures, Stevens-Johnson syndrome.
Long-Term Effects: Chronic, high-dose paracetamol use can cause liver damage. Long-term chlorpheniramine can lead to tolerance and decreased effectiveness.
Contraindications
Hypersensitivity to any component; severe cardiovascular disease; angle-closure glaucoma; urinary retention due to prostatic hyperplasia; pyloroduodenal obstruction; concomitant MAO inhibitor use; severe liver or kidney disease.
Drug Interactions
MAO inhibitors can cause a hypertensive crisis with phenylephrine. Alcohol increases liver damage risk with paracetamol and potentiates chlorpheniramine’s sedative effects. CNS depressants have additive CNS depression with chlorpheniramine. Anticholinergic drugs have additive anticholinergic effects with chlorpheniramine and amantadine. Beta-blockers can interact with phenylephrine. Consult a comprehensive drug interaction resource before co-prescribing.
Pregnancy and Breastfeeding
Pregnancy: Use with caution. The safety profile is not well-established.
Breastfeeding: May be excreted in breast milk and harm the baby. Discuss risks and benefits with the patient.
Drug Profile Summary
- Mechanism of Action: See above.
- Side Effects: See above.
- Contraindications: See above.
- Drug Interactions: See above.
- Pregnancy & Breastfeeding: See above.
- Dosage: See above.
- Monitoring Parameters: Liver function tests, renal function tests, blood pressure, cardiac rhythm, and any signs of allergic reactions or other adverse effects.
Popular Combinations
This combination itself is commonly used. However, individual components may be combined with other drugs depending on the specific symptoms being treated. Always check for potential interactions.
Precautions
Pre-screen for allergies, metabolic disorders, and organ dysfunction. Consider age-specific precautions and lifestyle factors like alcohol and smoking. Exercise caution in patients with renal/hepatic impairment, cardiovascular disease, or glaucoma. Avoid in pregnant/breastfeeding women unless benefits outweigh risks. The drug may cause drowsiness and impair cognitive function, affecting driving ability.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Amantadine + Chlorpheniramine Maleate + Paracetamol + Phenylephrine?
A: Standard adult dosage: One tablet (500 mg paracetamol, 2 mg chlorpheniramine maleate, 5 mg phenylephrine hydrochloride, and 50 mg amantadine) every 4-6 hours as needed, not exceeding 4 tablets per day. Pediatric dosages should be determined by a physician. Elderly patients may require dose adjustments.
Q2: What are the common side effects?
A: Drowsiness, dizziness, dry mouth, blurred vision, constipation, nausea, nervousness, and insomnia.
Q3: What are the serious side effects?
A: Allergic reactions, hepatotoxicity, cardiac arrhythmias, hallucinations, seizures, Stevens-Johnson syndrome.
Q4: Is this combination safe in pregnancy?
A: Use with caution. Consult a physician. Safety profile is not well-established.
Q5: Is this combination safe during breastfeeding?
A: It may be excreted in breast milk and potentially harm the infant. Consult a physician to weigh the risks and benefits.
Q6: Can I take this with alcohol?
A: Alcohol should be avoided as it increases the risk of liver damage with paracetamol and potentiates the sedative effects of chlorpheniramine.
Q7: What conditions should I be cautious about when prescribing this medication?
A: Cardiovascular disease, glaucoma, hypertension, renal impairment, hepatic dysfunction, and prostatic hyperplasia.
Q8: Are there any drug interactions I should be aware of?
A: Yes, clinically significant interactions exist with MAO inhibitors, alcohol, CNS depressants, anticholinergic drugs, and beta-blockers. Consult a drug interaction resource for a comprehensive list.
Q9: What should I monitor in patients taking this combination?
A: Liver function tests, renal function tests, blood pressure, and cardiac rhythm. Monitor for allergic reactions or other adverse events.
