Allergy Treatment

Allergies make us fell “unwell” and miserable.  Fortunately there are various allergy medications that can give allergy relief and make us feel well.  Allergy avoidance measures are sometimes impractical or impossible thus necessitating the need for allergy medications.  Your allergist can help determine the appropriate medications to treat your allergy problem.


Antihistamines are also called histamine receptor blockers, histamine receptor antagonists or histamine blockers.  These allergy medications work by blocking the effect of histamine and help relieve or prevent the development of itching, sneezing, runny nose, watery eyes and other allergy-related discomfort. Histamine is a natural occurring chemical in our body that gets released during an allergic reaction.  These drugs, classified as first generation and second generation antihistamines, work by preventing histamine from binding histamine receptors in our body.  First generation antihistamines effectively treat allergy symptoms however typically cause side-effects such as severe drowsiness, dryness and fatigue while second generation histamine blockers are equally effective for allergy treatment with much less or no side-effects.  Antihistamines can be taken orally, as capsule, liquid or tablet; or topically for the skin, eyes or nose, as creams, eye drops or nasal sprays. Your allergy doctor recommend the appropriate allergy treatment for your condition.

Oral Antihistamine Preparations available in the USA

First-Generation Antihistamines

  • Alkylamines-Bromphenireamine, Chlorphenireamine, Triprolidine
  • Piperazines-Buclizine, Cyclizine, Hydroxyzine, Meclizine
  • Piperidines-Azatidine, Cyproheptadine, Diphenylpyraline
  • Ethanolamines-Carbinoxamine, Clemastine, Dimenhydrinate, Diphenhydramine, Doxylamine
  • Ethylenediamines-Antazoline, pyrilamine, tripelennamine
  • Phenothiazines-Methdilazine, Promethazine
  • Others-Doxepin

Second-Generation Antihistamines

  • Alkylamines-Acrivastine
  • Piperazines-Cetirizine, Levocetirizine
  • Piperidines-Desloratidine, Fexofenadine, Loratidine

Topical Antihistamine Allergy Nasal Spray Preparations

  • Azelastine
  • Olapatidine

Topical Antihistamine Allergy Eye Drop Preparations

  • Azelastine
  • Epinastine
  • Ketotifen
  • Levocobastine
  • Olopatidine
  • Phenireamine

Topical Antihistamine Allergy Skin Creams

  • Diphenhydramine
  • Doxepin
  • Dimethinedine


Decongestants are allergy medications that work by constricting or shrinking blood vessels around a congested area, like your nose or your sinuses. Allergy symptoms of nasal and sinus pressure or congestion, and eye redness are commonly seen in allergic rhinitis or conjunctivitis.  Decongestants help relieve allergy symptoms such as the sensation of sinus swelling, sinus pressure, and nasal blockage or stuffiness when given orally or as a nasal spray. They are also effective in relieving eye redness when given as eye drops.  Caution however must be taken since they have known side-effects.  Oral decongestants can cause side-effects such as tremors, insomnia, palpitations, irregular heartbeat, and elevated blood pressure.  The topical decongestants such as nasal sprays and eye drops should be used sparingly since rebound effects may occur resulting on dependence on the drug.  Make sure to see your allergy doctor to discuss appropriate allergy treatment for your condition.

  • Oral decongestants: Oral decongestant are useful in relieving nasal and sinus congestion in upper respiratory illnesses including allergic rhinitis.  They are available in capsule, tablet or liquid form, and can be obtained in combination with antihistamines or as decongestants only. The two oral decongestants commercially available in the US include Phenylephrine hydrochloride and Pseudoephedrine hydrochloride.
  • Nasal sprays: Decongestant nasal sprays are effective in quickly relieving nasal stuffiness or blockage from upper respiratory illnesses such as allergic rhinitis, sinusitis or the common cold.  However, one must be cautious since the nasal membranes may become “dependent” causing rebound congestion if not used as directed.  The nasal decongestant sprays should not be used more than 3 consecutive days.  The decongestant nasal sprays available over the counter include Phenylephrine HCL and Oxymetazoline HCl.

Nasal Steroid Sprays

Topical nasal steroid sprays are the most effective drugs for treating allergic rhinitis because they block multiple aspects of allergic inflammation.  A few of the reasons topical nasal steroids work is because they decrease the amount and prevent the migration of inflammatory cells, suppress chemicals that cause allergic inflammation, decrease the effect of the allergic reaction and help heal the affected area.

The advantage to using nasal steroid sprays is it delivers a concentrated amount of the drug into the nasal area and with very limited amount being absorbed and distributed to other parts of the body.  This is really important since side effects seen when taking systemic steroids are thus avoided.

Leukotriene Receptor Blockers

Leukotrienes are one of the chemicals produced by our body during an allergic reaction.  They have been identified in contributing to allergic inflammation in patients with allergies, and bronchial constriction in patients with allergic asthma. Leukotriene blockers prevent leukotrienes from binding with leukotriene receptors in the body thus preventing another chemical from causing an allergic reaction.   Although initially approved for the treatment of allergic asthma, clinical studies have shown that leukotriene blockers are effective in treating allergic rhinitis. Leukotriene blockers, also called leukotriene antagonists, can be obtained by prescription from your allergy doctor and should be taken as a maintenance drug.