An allergy is an adverse response of the immune system to a hypersensitive trigger. These triggers can be anything from onions to pollen. At the same time, allergies can be chronic nasal congestion or sinus infections, and the time period of these allergies vary from person to person. Over-the-counter medicine for allergies may not work well for many cases such as asthma, rhinitis (hay fever) skin allergies, and  anaphylaxis. Prescription for an allergy medication is given by doctors after examining the patient and the symptoms.

Antihistamines and decongestants
The best prescription allergy medicines include antihistamines and decongestants. Some of the common names here include Allegra (fexofenadine) and Clarinex (desloratadine), which are known to be effective in reducing certain allergies such as congestion of the nose and stiffness in the chest.

Corticosteroids
Any list of the best prescription allergy medications includes corticosteroids, which are anti-inflammatory medicines. They come in several for such as nasal sprays like Flonase (fluticasone). These sprays, unlike OTC nose sprays, do not worsen the allergy symptoms with prolonged use. Corticosteroids come in various forms such as inhalers, pills, and injections. Inhalers are the prescribed allergy medicine for long-term symptoms of allergy such as asthma. Certain creams, lotions, and ointments are commonly prescribed allergy medication for skin-related allergy symptoms.

Anti leukotrienes
A popular anti leukotriene to treat allergies is Singulair (montelukast sodium), which is used to treat allergic rhinitis, asthma etc. These medicines work by fighting against chemicals called leukotriene that increase the inflammation.

Bronchodilators
This allergy medication is available in the form of inhalers, pills, liquid injections etc. All these medicines are generally used in the treatment of asthma.

Anti immunoglobulin
Anti-immunoglobulin antibodies are given to patients suffering from severe, persistent asthma caused by allergies.

Immunomodulators
Immunomodulators are topical medications that are used to treat skin allergies. These are used if other medications are not effective in reducing the symptoms.

Auto-injectable epinephrine
Auto-injectable epinephrine is used to treat the life-threatening allergic symptom known as anaphylaxis. This is caused due to severe allergic reaction to certain foods products or insect stings.

Preventive measures
Some preventive measures for allergies are to avoid foods and environmental conditions that cause an allergy. By careful observation, one can know the allergy triggers that cause the allergy and make sure to avoid those in the future. It is also important to see that the allergy medication you take does not have side effects that otherwise can lead to some other reactions in the body.

There is no particular medicine for all kinds of allergies and the medication is changed based on the symptoms. If the severity of the allergy is more then skin or blood tests are conducted and allergy shots are given to the patient if needed. The prescription allergy medicines mentioned above are the best solutions available for those suffering from allergies.