Nearly one in three French people suffers from an allergy and this figure is increasing from year to year. Antihistamines are leading drugs for relieving allergy symptoms. Which to take? H1? H2? For pollen? Without a prescription?
What is an antihistamine drug?
An antihistamine is a medicine that opposes the effects of histamine, an inflammatory substance released in large quantities by the cells in the event of an allergic reaction. Antihistamine medications come in different forms (capsules, nasal spray, tablet, eye drops…) and are effective in reducing many allergic symptoms such as sneezing, runny nose, watery or itchy eyes.
H1 antihistamines
H1 antihistamines target H1 receptors and help fight allergic phenomena. These are generally the antihistamines based on cetirizine, loratadine and desloratadine. “H1 antihistamines are effective in various allergy symptoms and in particular on rhinitis, conjunctivitis (in the form of eye drops), urticaria and eczema. They are, however, quite not very effective on asthma” explains Dr. Madiha Ellaffi, pulmonologist and allergist. “It can happen that after a few times of use, a molecule becomes less effective on a patient, this is called the escape effect. It is then wise to try another molecule to find a efficiency.” H1 antihistamines only improve symptoms but do not treat the cause. They can be prescribed for both adults and children, and are offered for the latter in the form of syrup.
H2 antihistamines
H2 antihistamines act on H2 receptors located mainly in the gastric mucosa, responsible for gastric acidity. They are therefore effective in reducing the acid secretion of the stomach occurring during a gastroesophageal reflux, but have a limited effect on the treatment of allergic reactions.
List of antihistamines sold without a prescription
Many antihistamines are sold in pharmacies without a prescription. They are not less effective but more expensive and not
List of prescription antihistamines
The most commonly prescribed are Xysall®, Clarityne®, Zyrtec®, Kestin®, Aerius®, Virlix® or Bilaska®.
Contraindications
Pay attention to current treatments and associated pathologies. Always read the leaflet that is in the box containing the medication.
Side effects
Antihistamine medications can have side effects, the best known of which is drowsiness. “If second-generation antihistamines cause fewer side effects, some allergic people remain sensitive to them. This is particularly the case in people of small build, since the dosage of antihistamines is the same for everyone” recalls Dr. Madiha Ellaffi.
Pregnancy and breast feeding
“As a precautionary principle, antihistamines are stopped during the first trimester even if they are not teratogenic, explains the specialist. In the second and third trimester, desloratadine (Aérius®) may be authorized for the most severe allergies.
Thanks to Dr Madiha Ellaffi, pulmonologist and allergist.