An allergy is a condition where the immune system of the body reacts abnormally against a foreign substance. There are many types of allergies such as food allergy, drug allergy, animal allergy, etc. Most types of allergies are not typically harmful to mankind and can be treated with medicines or drugs specifically curated to treat different types of allergy.
Allergies can be very minor or severe depending upon the type of allergen. The most common symptoms of allergy include but not limited to skin rashes, patches of redness in the skin, inflammation of the skin, watery eyes, itching, sneezing, running nose, etc.
The common symptoms of allergy are generally termed as Allergic Rhinitis. Many drugs are used to treat this condition and the two most common types are – Chlorphenamine or Chlorpheniramine, also known as CPM and Cetirizine.
CPM vs Cetirizine
The difference between CPM and Cetirizine is that CPM is an antihistamine used for treating the allergic conditions, and it takes action within six hours of use. Cetirizine is a second-generation antihistamine also used for treating allergic conditions, and it takes action within an hour of use.
Both CPM and Cetirizine belong to the second generation of Antihistamines and are generally available over-the-counter (OTC) and can be taken by mouth in a tablet form. Antihistamines of the second generation will not cause as much drowsiness as compared to the first generation.
Comparison Table Between CPM and Cetirizine (in Tabular Form)
|Parâmetro de Comparação||Clorfenamina||Cetirizina|
|Química||É uma alquilamina e exibe isomerismo óptico||Consiste em estereoisômeros dos tipos L e D|
|Síntese||A síntese é feita na presença de um composto inorgânico denominado amida de sódio (NaNH2)||A síntese é feita na presença de um composto inorgânico denominado carbonato de sódio (Na2CO3) e um isômero denominado xileno (C8H10)|
|Meia vida||In adults, the half-life of elimination ranges from 13.9 to 43.4 hours||In adults, the half-life of elimination ranges between 6.5 and 10 hours|
|Efeitos colaterais||Os efeitos colaterais incluem, mas não se limitam a boca seca, tontura, constipação, náusea||Os efeitos colaterais incluem, mas não se limitam a dor de cabeça, sonolência, fadiga|
|Administração de Drogas||Pode ser administrado por via oral ou intravenosa ou intramuscular ou como injeções subcutâneas, dependendo da condição e necessidade de um indivíduo||Pode ser administrado apenas por via oral na forma de cápsula ou comprimido ou xarope|
What is Chlorphenamine?
Chlorphenamine is also known as Chlorpheniramine or CPM and it is a type of Antihistamine drug used to treat different types of allergies such as Allergic Rhinitis. It is available as a generic medicine and also over-the-counter.
The use of CPM came into existence for use in the medical field in the year 1949. It does not pose any risk to an individual when administered in prescribed quantities by a physician. Despite this, many common side effects are found to occur.
CPM has a molecular formula of C16H19ClN2 and acts as a powerful inverse agonist of the histamine H1 receptor. It is synthesized using pyridine in the presence of sodium amide by hydrolysis and decarboxylation process.
It is commonly sold under the drug name of Chlortrimeton and Piriton. The general side effects observed after administering CPM in individuals are dry mouth, dizziness, anxiety, constipation, and nausea.
What is Cetirizine?
Cetirizine is a type of Antihistamine drug used to treat Allergic Rhinitis and is predominantly used in the treatment of Hay’s fever and chronic Hives disease. It belongs to the second generation of antihistamines and is available over-the-counter and also as a generic medicine for consumption.
The use of Cetirizine came into existence for use in the medical field in the year 1987. It works by blocking the histamine H1 receptor and acts as a selective antagonist.
Cetirizine has a molecular formula of C21H25ClN2O3 and is synthesized in the presence of sodium carbonate and xylene by the saponification process and yields a product of carboxylic acid.
It is generally sold under the drug name as Zyrtec and Incidal. The most common side effects reported by the individuals after consuming cetirizine are fatigue, drowsiness, headache, and aggression.
We need to store this Cetirizine at room temperature and avoid excessive heat and moisture. Keep it away from children and preserve it in the same tightly closed container it came in.
Main Differences Between CPM and Cetirizine
- Both Chlorphenamine (CPM) and Cetirizine produce effective results in treating allergic rhinitis and other similar conditions. The main difference between Chlorphenamine and Cetirizine is the chemical composition and the process of synthesizing inorganic compounds of both the drugs.
- The bio-availability of Chlorphenamine is 25% to 50% whereas the bio-availability of Cetirizine is well above 70%.
- The onset of action of Chlorphenamine is within 6 hours but Cetirizine begins the onset of action generally within 1 hour. However, the effect of both drugs remains for 24 hours.
- The capacity of binding of protein in Chlorphenamine is 72% whereas the capacity of binding of protein ranges from 88% to 96% in Cetirizine.
- In the case of Chlorphenamine, the half-life of elimination in adults who are found to be healthy ranges from 13.9 hours to 43.4 hours but in the case of Cetirizine, it ranges from 6.5 hours to 10 hours.
Both Chlorphenamine and Cetirizine are found to be very effective in treating the common allergic conditions such as allergic rhinitis, etc in humans and animals. They are easily available in the market and do not require a prescription.
However, it is advised to consume the medicines as directed by a registered physician. The consumption of these drugs is found to induce drowsiness, fatigue, headache, and other such common side effects. But the side effects are not found to sustain for longer durations and are very rarely found to be adverse in certain individuals.
The drugs can be taken by mouth and the onset of action is quick. However, the effects of taking drugs can be seen for 24 hours in an individual. In conclusion, Cetirizine is found to be more effective than CPM.