Antihistamines


Antihistamines are a vital subcategory of pharmaceutical Active Pharmaceutical Ingredients (APIs) widely used in the treatment of allergies and allergic reactions. These compounds work by blocking the action of histamines, which are responsible for triggering allergic symptoms such as itching, sneezing, runny nose, and watery eyes.

Antihistamines can be classified into two main categories: first-generation and second-generation antihistamines. First-generation antihistamines, such as diphenhydramine and chlorpheniramine, have been in use for several decades. They are effective in relieving allergy symptoms but are associated with drowsiness and other side effects due to their ability to cross the blood-brain barrier.

On the other hand, second-generation antihistamines, including cetirizine, loratadine, and fexofenadine, offer similar allergy relief with fewer sedative effects. These newer antihistamines are preferred for their improved safety profiles, making them suitable for use during the day without causing significant drowsiness.

Antihistamines are available in various forms, including tablets, capsules, syrups, and topical creams. They are extensively used to manage conditions such as hay fever, hives, allergic rhinitis, and insect bites. Moreover, antihistamines may also be combined with decongestants or other medications to provide relief from nasal congestion and sinus symptoms.

As pharmaceutical APIs, antihistamines are produced through meticulous synthesis and manufacturing processes, adhering to strict quality standards. These APIs serve as the active components in various branded and generic pharmaceutical formulations, making them crucial in the pharmaceutical industry's production of allergy medications.

In conclusion, antihistamines are a significant subcategory of pharmaceutical APIs widely used for alleviating allergy symptoms. Their classification into first- and second-generation antihistamines offers options based on efficacy and sedative effects. By blocking histamines, antihistamines provide relief from common allergic reactions, making them essential in the development of effective allergy medications.

NameCAS numberCategoryAmount of suppliers
AcrivastineAntihistamines3
Alcaftadine147084-10-4Antihistamines8
Antazoline91-75-8Antihistamines2
Bepotastine125602-71-3Antihistamines10
Bilastine202189-78-4Antihistamines13
Brompheniramine86-22-6Antihistamines4
Buclizine82-95-1Antihistamines3
Carbinoxamine486-16-8Antihistamines4
Cetirizine83881-51-0Antihistamines41
Cetirizine HCl83881-52-1Antihistamines3
Chlorcyclizine82-93-9Antihistamines1
Chloropyramine59-32-5Antihistamines1
Chlorphenamine132-22-9Antihistamines19
Clemastine15686-51-8Antihistamines4
Clemastine fumarate610309-89-2Antihistamines1
Cyclizine82-92-8Antihistamines5
Cyproheptadine129-03-3Antihistamines14
Desloratadine100643-71-8Antihistamines37
Dexbrompheniramine132-21-8Antihistamines3
Dexchlorpheniramine maleateAntihistamines8
Dimetindene maleate5636-83-9Antihistamines5
Diphenhydramine58-73-1Antihistamines28
Diphenylpyraline hydrochloride132-18-3Antihistamines1
Domiphen13900-14-6Antihistamines1
Doxylamine469-21-6Antihistamines9
Ebastine90729-43-4Antihistamines15
Emedastine87233-61-2Antihistamines4
Epinastine80012-43-7Antihistamines16
Fexofenadine83799-24-0Antihistamines47
Hydroxyzine68-88-2Antihistamines7
Isothipendyl482-15-5Antihistamines1
Ketotifen34580-13-7Antihistamines10
Ketotifen fumarate34580-14-8Antihistamines1
Levocabastine79516-68-0Antihistamines5
Levocetirizine130018-77-8Antihistamines19
Levocetirizine Dihydrochloride130018-87-0Antihistamines9
Levocetirizine HydrochlorideAntihistamines11
Loratadine79794-75-5Antihistamines37
Mebhydrolin NapadisylateAntihistamines1
Mebhydroline Napadisylate6153-33-9Antihistamines2
Meclizine569-65-3Antihistamines16
Mepyramine91-84-9Antihistamines7
Mequitazine29216-28-2Antihistamines3
Mizolastine108612-45-9Antihistamines2
Olopatadine113806-05-6Antihistamines23
Oxatomide60607-34-3Antihistamines4
Pheniramine86-21-5Antihistamines9
Phenyltoloxamine Citrate3717-88-2Antihistamines1
Promethazine60-87-7Antihistamines21
RupatadineAntihistamines9
Triprolidine486-12-4Antihistamines13