Cetirizine dihydrochloride is the active component of certain medications used to alleviate the symptoms produced in allergic processes. Its mechanism of action is aimed at inhibiting the action of histamine. Because it is a second-generation antihistamine, it causes fewer adverse reactions; for example, just like the first-generation ones, it does not cause drowsiness.
The effects of Cetirizine are long-lasting, allowing for more flexible dosing. At FastlyHealwe, tell you more about Cetirizine: what it is for, dosage, side effects, and contraindications.
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Cetirizine: what is it for?
Cetirizine is a molecule that works by blocking the action of histamine. This is why it is classified as an antihistamine. Histamine has a double role: it can act as a hormone or a neurotransmitter depending on the tissue in which it is released. It is recognized as the main involved in allergic reactions when it binds to the H1 receptor. Antihistamines, such as Cetirizine, act on this same receptor, inhibiting the effect of histamine.
Usually, when histamine acts on the H1 receptor, it activates a chain of reactions that will produce type 1 hypersensitization, better known as allergy. The action of Cetirizine will prevent the appearance of symptoms associated with allergic processes. According to the Spanish Agency for Medicines and Health Products , Cetirizine is indicated to relieve nasal and ocular symptoms of seasonal and perennial allergic rhinitis. In other words, this medicine serves to reduce the following symptoms temporarily:
- Runny nose.
- Itchy nose and throat.
- Irritation of the eyes.
- Redness and itching of the skin (chronic idiopathic urticaria).
These symptoms usually occur as a reaction to a foreign agent that enters the body, called allergens. Some examples are pollen, house dust, mites, molds, and other substances in the air. In children, Cetirizine is used to treat seasonal and perennial allergic rhinitis and chronic idiopathic urticaria that causes itching, redness, and hives on the skin.
Cetirizine: dose and routes of administration
Cetirizine is marketed in different forms that are all administered orally. It can be in the form of:
- Soft capsules.
- Pediatric drops.
You should follow your doctor’s instructions when taking Cetirizine without increasing or decreasing the indicated doses. Also, take the time to read the leaflet and the medicine label. If in doubt, consult your doctor or pharmacist.
The usual doses vary according to the age of the patient:
- For children 1 to 2 years old weighing less than 20 kg, a dose of 2.5 mg per day is recommended.
- For children from 2 to 6 years of age over 20 kg, a dose of 5 mg or divided into two doses is recommended.
- For children 6 to 12 years of age, a dose of 5 mg daily is recommended, which can be administered as an oral solution or half a tablet.
- For children over 12 years of age and adults, a daily 10 mg tablet or half a tablet twice a day is recommended to reduce adverse effects.
It is not good to exceed the indicated doses. As it is a medicine ingested orally, it is advisable to take it with a sufficient amount of liquid, preferably water. Food intake does not affect the absorption of Cetirizine, so if it is taken once a day, you can do it at dinner and if you take it twice, take medicine with breakfast and then with dinner, trying to do it all every day at the same time.
If you need to undergo an allergy test, do not take Cetirizine for three days before the test, and remember to discuss this with your doctor. If you suffer from kidney or liver diseases, the doctor should adjust the dose.
Cetirizine: side effects
Many medications cause adverse effects, and Cetirizine is no exception, although not all patients suffer from them. It is considered a second-generation antihistamine, which indicates that it produces fewer side effects than the first-generation ones. It usually doesn’t cause drowsiness.
In addition, due to its prolonged action, it allows adjusting the dosage. If the adverse effects are powerful, the daily dose can be divided into two doses. This strategy works very well in patients with drowsiness and agitation, symptoms that disappear when the amount is lowered. Mild and transient effects have been observed specifically with Cetirizine. Among the most frequent are:
- Drowsiness and fatigue
- Headache, dizziness, and agitation (especially in children).
- Dry mouth and gastrointestinal upset (stomach pain, diarrhea, or vomiting)
Some side effects can be severe, so it is essential to pay attention to them. Stop treatment and go to the emergency room if you have severe symptoms such as:
- Swelling of the eyelids, lips, or face.
- Difficulty breathing.
- Swelling of the hands, feet, or ankles.
For some patients, taking Cetirizine is contraindicated, for example, if they are allergic to Cetirizine, hydroxyzine, or other medications. As we have mentioned before, Cetirizine comes in different commercial presentations containing various excipients. People can be allergic to both Cetirizine itself and some of the excipients. In such cases, it is recommended to look closely at the medicine label to verify if you are not allergic to any of its components. If it is, it is recommended not to take it.
In the case of tablets, they contain lactose, so if you suffer from galactose intolerance, you should not take them. On the other hand, the oral solution and the drops have methyl parahydroxybenzoate and propyl parahydroxybenzoate, both of which cause allergic reactions in some people, with symptoms such as headache, gastric upset, and diarrhea.
The allergy symptoms of Cetirizine include:
- Shortness of breath and asthma attack.
- Difficulty speaking due to swelling of the vocal cords, throat, tongue, lips, and face.
- Rash on the skin.
- Anaphylactic shock.
It is also essential to inform your doctor before using this medicine, if:
- You have liver or kidney disease.
- You have acute asthma attacks.
- You are pregnant or planning to be. If you become pregnant and are taking Cetirizine, consult your doctor. Also, if you are breastfeeding, Cetirizine passes into breast milk.
- Operates heavy machinery or drives vehicles regularly.
- You use other medications that depress the Central Nervous System, such as sedatives, tranquilizers, antidepressants, medicines for seizures, or drugs to sleep. Neither the antiasthmatic theophylline nor oral anticoagulants, such as acenocoumarol.
- If you drink alcoholic beverages frequently.
In all the cases mentioned above, the doctor will advise you not to take this medicine or adjust the dose so that it does not cause adverse effects.
This article is merely informative, at FastlyHeal .com we do not have the power to prescribe medical treatments or make any type of diagnosis. We invite you to see a doctor in the case of presenting any type of condition or discomfort.
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I am a Surgeon with a diploma in comprehensive ultrasound and surgical care residency, an area I am specializing in. During the exercise of my profession, I have realized the need for patients to know the diseases they suffer, and I can tell you that a large part of their complications is due to a lack of information. Being a health web writer allows me to transmit my experience, without borders, to all those readers eager for knowledge, educate them in the prevention of diseases and promote a healthy lifestyle.