dexchlorpheniramine and pseudoephedrine

Action and Spectrum

Actions and Spectrum: 

Action: 

dexchlorpheniramine: 

dexchlorpheniramine is an antihistamine that works by blocking the effects of histamine, a chemical released during an allergic reaction. It specifically targets the H1 histamine receptors, inhibiting their activation. This action helps reduce or prevent the symptoms associated with allergies, such as sneezing, itching, runny nose, and watery eyes. dexchlorpheniramine also possesses mild sedative properties, which can cause drowsiness in some individuals. 

Spectrum:  

dexchlorpheniramine is primarily indicated for the relief of symptoms associated with allergic rhinitis (hay fever), including seasonal and perennial allergies. It can also be used to alleviate symptoms caused by other allergic conditions, such as allergic conjunctivitis (eye inflammation due to allergies) and allergic skin reactions (e.g., hives). Due to its sedative effects, dexchlorpheniramine is sometimes included in nighttime formulations of cold and allergy medications to aid with sleep. 

Pseudoephedrine:  

Action: 

pseudoephedrine is a sympathomimetic decongestant that works by constricting the blood vessels in the nasal passages, thereby reducing swelling and congestion. It activates alpha-adrenergic receptors, leading to vasoconstriction and decreased nasal blood flow. This action helps alleviate nasal congestion and sinus pressure associated with conditions like the common cold, hay fever, and sinusitis. 

Spectrum: pseudoephedrine is primarily used to temporarily relieve nasal congestion caused by various upper respiratory tract infections, allergic rhinitis, and sinus congestion. It is commonly included in over-the-counter cold and allergy medications, usually in combination with antihistamines like dexchlorpheniramine or other active ingredients to provide comprehensive symptom relief. 

Drug Interaction

Adverse Reaction

Frequency not defined  

shortness of breath 

severe headache 

dangerously high blood pressure 

anxiety 

unusual weakness 

easy bruising or bleeding 

fast or uneven heart rate 

rapid pulse 

chest pain 

little or no urinating 

seizure (convulsions) 

tremor 

severe nervousness 

hallucinations 

confusion 

Black Box Warning

Black Box Warning:  

It is essential to avoid the combination of dexchlorpheniramine and pseudoephedrine
If you have consumed a MAO inhibitor in the past two weeks.This combination can lead to a potentially hazardous drug interaction. 

Contraindication / Caution

Contraindication/Caution:  

dexchlorpheniramine: 

Hypersensitivity: Individuals with a known hypersensitivity or allergy to dexchlorpheniramine or any of its components should avoid using this medication. 

Severe liver disease: dexchlorpheniramine should be used with caution in individuals with severe liver disease as it may worsen the condition or lead to complications. 

Glaucoma: dexchlorpheniramine can increase intraocular pressure and should be used cautiously in individuals with glaucoma. 

Urinary retention: The medication may exacerbate urinary retention in individuals with bladder obstruction or urinary retention issues. 

Asthma or chronic obstructive pulmonary disease (COPD): dexchlorpheniramine may thicken respiratory secretions and impair lung function, so caution should be exercised in individuals with these conditions. 

pseudoephedrine: 

Hypersensitivity: Individuals with a known hypersensitivity or allergy to pseudoephedrine or any of its components should avoid using this medication. 

Severe hypertension: pseudoephedrine can increase blood pressure, so it should be used with caution or avoided altogether in individuals with severe hypertension. 

Cardiovascular disease: pseudoephedrine may exacerbate certain heart conditions, including coronary artery disease, arrhythmias, and heart failure. It should be used cautiously in individuals with these conditions. 

Hyperthyroidism: pseudoephedrine can stimulate the release of thyroid hormones, potentially worsening the symptoms of hyperthyroidism. Caution should be exercised in individuals with this condition. 

Prostate enlargement: pseudoephedrine can worsen urinary symptoms in individuals with benign prostatic hyperplasia (enlarged prostate) by causing urinary retention. It should be used cautiously in such individuals. 

Pregnancy / Lactation

Pregnancy warnings:     

Pregnancy category: N/A 

Lactation: Excreted into human milk is unknown 

Pregnancy Categories:         

Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester. 

Category B: There were a lack of studies on pregnant women and no evidence of risk to the fetus in animal experiments.   

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.   

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: There is no data available for the drug under this category

Pharmacology

Pharmacology:  

dexchlorpheniramine and pseudoephedrine are two active ingredients commonly found in combination medications used to relieve symptoms associated with allergies and the common cold 

Pharmacodynamics:  

dexchlorpheniramine: 

dexchlorpheniramine is a first-generation antihistamine, which means it blocks the effects of histamine, a substance released during an allergic reaction. 

It acts as a selective antagonist at the histamine H1 receptor, preventing the binding of histamine to these receptors and thereby reducing or preventing allergic symptoms. 

pseudoephedrine: 

pseudoephedrine is a sympathomimetic agent and a decongestant, which means it acts by stimulating the sympathetic nervous system and reducing nasal congestion. 

It works by indirectly stimulating the adrenergic receptors, leading to vasoconstriction of nasal blood vessels, and reducing the production of nasal secretions. 

Pharmacokinetics: 

Absorption: 

dexchlorpheniramine: dexchlorpheniramine is well-absorbed after oral administration. It is rapidly and extensively absorbed from the gastrointestinal tract. 

pseudoephedrine: pseudoephedrine is also well-absorbed orally. It is readily absorbed from the gastrointestinal tract. 

Distribution: 

dexchlorpheniramine: dexchlorpheniramine is distributed throughout the body, including the central nervous system (CNS). It readily crosses the blood-brain barrier. 

pseudoephedrine: pseudoephedrine is distributed throughout the body, including the CNS. It can also cross the blood-brain barrier. 

Metabolism 

dexchlorpheniramine: dexchlorpheniramine is extensively metabolized in the liver through oxidation and conjugation reactions. The primary metabolic pathway is N-demethylation. 

pseudoephedrine: pseudoephedrine undergoes hepatic metabolism, primarily through N-demethylation and aromatic hydroxylation. The major metabolite is norpseudoephedrine. 

Excretion and Elimination 

dexchlorpheniramine: dexchlorpheniramine and its metabolites are excreted primarily in the urine. The elimination half-life is approximately 16-21 hours. 

pseudoephedrine: pseudoephedrine and its metabolites are excreted mainly in the urine. The elimination half-life is around 5-8 hours. 

Adminstartion

Administration:  

Timing: Take the medication as directed. It is usually recommended to take dexchlorpheniramine and pseudoephedrine every 4 to 6 hours, depending on the formulation and strength of the product. Do not exceed the maximum daily dosage.  

Oral administration: 

 If using tablets or capsules, swallow them whole with a glass of water. 

If using a syrup, use the provided measuring device to ensure an accurate dose. 

Shake the bottle well before use. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: dexchlorpheniramine and pseudoephedrine 

Why do we use dexchlorpheniramine and pseudoephedrine?  

Allergic rhinitis: dexchlorpheniramine and pseudoephedrine are often used together to alleviate the symptoms of allergic rhinitis, commonly known as hay fever. They can help relieve nasal congestion, sneezing, itching, and runny nose caused by allergies. 

Sinus congestion: pseudoephedrine, a decongestant, is particularly effective in reducing nasal congestion caused by sinusitis or the common cold.  

Common cold symptoms: Both dexchlorpheniramine and pseudoephedrine can alleviate a range of symptoms commonly linked to the common cold, such as nasal congestion, a runny nose, sneezing, and post-nasal drip. 

Nasal allergies: dexchlorpheniramine, an antihistamine, blocks the action of histamine in the body, reducing symptoms such as itching, watery eyes, and nasal itching associated with allergic reactions. 

Seasonal allergies: dexchlorpheniramine and pseudoephedrine are often used together to manage symptoms caused by seasonal allergies. These medications can help alleviate symptoms like sneezing, itchy and watery eyes, and congestion.