Usage
- Chlorpheniramine Maleate + Paracetamol is prescribed for the symptomatic relief of the common cold, flu, and allergies. It addresses symptoms such as fever, headache, body aches, runny or stuffy nose, sneezing, itching, and watery eyes. Some formulations may also provide relief from sinus congestion and toothache.
- Pharmacological Classification: This drug is a combination product containing a first-generation antihistamine (chlorpheniramine maleate) and an analgesic/antipyretic (paracetamol). It may also be combined with other active ingredients like phenylpropanolamine, phenylephrine hydrochloride, caffeine, or vitamin C, depending on the specific formulation.
- Mechanism of Action: Chlorpheniramine maleate competes with histamine for H1-receptor sites, reducing the effects of histamine release associated with allergic reactions. Paracetamol inhibits prostaglandin synthesis, primarily in the central nervous system, which reduces fever and pain.
Alternate Names
- This combination medication doesn’t have a specific international nonproprietary name (INN). It is often referred to by the names of its constituents.
- Brand Names: A wide variety of brand names exist depending upon the region and specific added ingredients like Apflu, Febrilex, Sinarest Plus, Royalkel, Snip, Basecold, and KOLQ. This is not an exhaustive list.
How It Works
- Pharmacodynamics: Chlorpheniramine provides antihistaminic action, reducing allergy symptoms. Paracetamol exerts its analgesic and antipyretic effects through central inhibition of prostaglandin synthesis. Depending on the formulation, additional ingredients can offer decongestant, antitussive, and other effects.
- Pharmacokinetics: Both chlorpheniramine and paracetamol are well-absorbed orally. Chlorpheniramine is metabolized in the liver, primarily by CYP450 enzymes, and its metabolites are excreted in the urine. Paracetamol is also metabolized in the liver, with most being conjugated and excreted in the urine; a small amount is metabolized via CYP2E1 to a hepatotoxic metabolite, which is normally detoxified by glutathione.
- Mode of Action: Chlorpheniramine binds competitively to H1 receptors, antagonizing the actions of histamine. Paracetamol’s precise mechanism of action is not fully understood but is thought to involve central inhibition of COX enzymes, with minimal effects on peripheral COX activity.
- Receptor Binding, Enzyme Inhibition, or Neurotransmitter Modulation: Chlorpheniramine binds to histamine H1 receptors. Paracetamol may have an effect on COX activity and also may interact with the endocannabinoid system.
- Elimination Pathways: Both chlorpheniramine and paracetamol are predominantly metabolized in the liver and excreted by the kidneys.
Dosage
Standard Dosage
Adults:
- The typical adult dose of paracetamol is 500-1000 mg every 4-6 hours as needed, not exceeding 4000 mg in 24 hours. Chlorpheniramine dosages vary, generally 4 mg every 4-6 hours, not to exceed 24 mg daily. Doses should be adjusted based on the specific product formulation. Always check the product labeling.
Children:
- Pediatric dosages are weight- or age-based and should be carefully determined. For paracetamol, the usual dose is 10-15 mg/kg every 4-6 hours, not to exceed 5 doses in 24 hours. Pediatric doses of chlorpheniramine should follow product labeling or a medical professional’s advice.
Special Cases:
- Elderly Patients: Dose reductions may be necessary due to age-related declines in hepatic and renal function.
- Patients with Renal Impairment: Paracetamol dosage should be adjusted based on creatinine clearance. Chlorpheniramine should be used with caution.
- Patients with Hepatic Dysfunction: Paracetamol dosages should be reduced, and chlorpheniramine should be used with caution.
- Patients with Comorbid Conditions: Use with caution in patients with hypertension, cardiovascular disease, diabetes, glaucoma, hyperthyroidism, prostatic hypertrophy, or other relevant conditions.
Clinical Use Cases
Chlorpheniramine + Paracetamol is primarily indicated for outpatient management of cold and flu symptoms. Its use in specific clinical settings like intubation, surgical procedures, mechanical ventilation, ICU use, and emergency situations is typically not recommended. Other targeted therapies are preferred in those settings.
Dosage Adjustments
Dose modifications are based on age, weight, renal function, and hepatic function. Consider genetic polymorphisms affecting drug metabolism, especially for paracetamol, as some individuals might have reduced capacity to metabolize the drug, increasing the risk of hepatotoxicity even at standard doses.
Side Effects
Common Side Effects
- Drowsiness
- Dizziness
- Blurred vision
- Dry mouth, nose, and throat
- Constipation
- Upset stomach
Rare but Serious Side Effects
- Severe allergic reactions (e.g., skin rash, itching/swelling, severe dizziness, trouble breathing)
- Hepatotoxicity (with paracetamol overdose)
Long-Term Effects
- Chronic paracetamol use at high doses can lead to liver damage and renal complications. Long-term use of chlorpheniramine is not recommended due to potential tolerance and other adverse effects.
Adverse Drug Reactions (ADR)
- Any signs of hypersensitivity or hepatotoxicity should prompt immediate discontinuation of the medication and supportive care.
Contraindications
- Hypersensitivity to chlorpheniramine or paracetamol.
- Severe hepatic impairment.
- Concurrent or recent use of MAOIs (for chlorpheniramine).
- Certain formulations may have specific contraindications related to additional components like phenylpropanolamine or phenylephrine (e.g., severe hypertension, coronary artery disease).
Drug Interactions
- Alcohol (increases risk of liver damage with paracetamol).
- MAOIs (intensify anticholinergic effects of chlorpheniramine).
- Other CNS depressants (additive sedative effects).
- Anticholinergic medications (additive anticholinergic effects).
- Medications metabolized by CYP450 enzymes (potential for interactions).
Pregnancy and Breastfeeding
- Pregnancy: Safety not well-established. Consult a doctor before use.
- Breastfeeding: Small, occasional doses of chlorpheniramine may be acceptable. Safer alternatives are preferred. Paracetamol is generally considered safe during breastfeeding in recommended doses.
Drug Profile Summary
- Mechanism of Action: Chlorpheniramine: H1 receptor antagonist. Paracetamol: Inhibits prostaglandin synthesis.
- Side Effects: Drowsiness, dizziness, dry mouth, constipation, blurred vision, upset stomach. Serious side effects: hepatotoxicity, hypersensitivity.
- Contraindications: Hypersensitivity, severe hepatic impairment, MAOI use, certain conditions depending on formulation components.
- Drug Interactions: Alcohol, MAOIs, CNS depressants, anticholinergics, CYP450 substrates.
- Pregnancy & Breastfeeding: Use with caution during pregnancy; consult a doctor. Small, occasional doses of chlorpheniramine may be acceptable during breastfeeding.
- Dosage: Varies depending on formulation and age. See specific product labeling.
- Monitoring Parameters: Liver function tests with prolonged or high-dose paracetamol use.
Popular Combinations
- Chlorpheniramine + Paracetamol often combined with decongestants (e.g., phenylephrine, phenylpropanolamine, pseudoephedrine), antitussives (e.g., dextromethorphan), caffeine, and Vitamin C.
Precautions
- Assess for pre-existing conditions (hepatic/renal impairment, hypertension, cardiovascular disease, etc.).
- Caution in elderly patients, pregnant/breastfeeding women, and children.
- Avoid alcohol.
- Monitor for side effects.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Chlorpheniramine Maleate + Paracetamol?
A: Dosage varies depending on age, formulation, and indication. Consult the specific product labeling or a healthcare professional for accurate guidance.
Q2: Can this medication be used in children?
A: Yes, but pediatric dosages are lower and should be calculated based on weight or age. Not all formulations are suitable for all pediatric age groups.
Q3: What are the common side effects?
A: Drowsiness, dizziness, dry mouth, blurred vision, and constipation are common side effects.
Q4: Are there any serious side effects to be aware of?
A: Paracetamol overdose can cause liver damage. Allergic reactions can also occur.
Q5: Can I take this medication if I am pregnant or breastfeeding?
A: Consult a doctor before use during pregnancy or breastfeeding.
Q6: Can I drink alcohol while taking this medication?
A: Alcohol should be avoided, as it can increase the risk of liver damage with paracetamol.
Q7: What should I do if I miss a dose?
A: Take the missed dose as soon as you remember, unless it is almost time for your next dose. Do not double the dose.
Q8: Can I take this medication with other over-the-counter medications?
A: Consult a doctor or pharmacist before taking this medication with other medications, including over-the-counter drugs and supplements, to avoid potential drug interactions. Be especially mindful of other products containing paracetamol.
Q9: How long should I take this medication?
A: This medicine is intended for short-term use to relieve symptoms. Consult a doctor if symptoms persist beyond a few days.
Q10: Can this drug be used in patients with liver or kidney problems?
A: Use with caution in patients with liver or kidney disease. Dosage adjustments might be necessary. Consult a doctor before use.
