Using Various Medications to Treat Allergies

Antihistamines are the most widely used medications to treat allergies. They block histamine's attachment to cells, thereby lessening a lot of symptoms, but they have no direct effect on stuffiness. 
 
New “second generation” antihistamines are mostly free of side effects, but you should always be aware of the possibility of drowsiness or slowed reaction time when you take antihistamines.
 
Oral decongestants 
Although safe for many people, oral decongestants have the potential to adversely affect high blood pressure, heart conditions, diabetes, thyroid disorders, glaucoma and prostate problems. They can also cause jitteriness, sleep disturbance and palpitations. 
 
Decongestant nasal sprays and drops 
Patients are advised against using decongestant nasal sprays for longer than three consecutive days because they can cause “rebound congestion,” resulting in ever-worsening nasal stuffiness and dependency upon the medication. The anti-inflammatory steroid nasal sprays are largely free of side effects when used properly and can be very effective if used regularly. There is also an antihistamine spray that includes anti-inflammatory effects, and a nasal spray that has a drying effect that can be use to advantage for excessive runny nose. 
 
Medications used to treat asthma
The most common prescription medications for day-to-day control are:
 
Inhaled anti-inflammatory steroids are presently considered the first choice for patients who experience asthma symptoms more than twice a week. They do for the lungs what the nasal anti-inflammatory sprays do for the nose: they reduce inflammation - which is the underlying cause of allergic and asthmatic reactions - and they do so by working on the inner surface of the lungs, not deep within the body. If begun early enough, they can reverse tissue changes in the lungs known as “remodeling.”
Bronchodilators dilate the bronchioles, or air passageways, by relaxing the strands of smooth muscle that constrict them. Although bronchodilators are mostly used by inhalation, oral and injectable forms are also available.
There are other types of inhalers that can be helpful for some asthma patients.
The most recently developed category of medications for the treatment of asthma are the anti-leukotrienes.
Theophylline has been used to treat asthma for years but has been largely supplanted by newer medications.
 
Asthma exacerbations may require oral or intravenous steroids and/or injected epinephrine.
 
Steroids
Some patients are apprehensive about steroid side effects. But there is little reason to be overly concerned with the modern-day steroid sprays and inhalers being used for allergies and asthma. Some of the newer cortisone-type medications for hay fever and allergic asthma often bring about remarkable improvement and can be safe for long-term use.
 
Mast cell stabilizers
IgE allergic antibodies attach to the surface of “mast cells.” When the allergens corresponding to those antibodies are present, the allergens and IgE antibodies link up, initiating events inside the mast cell that culminate in the release of histamine and other chemicals that diffuse away and exert effects upon susceptible tissues. Mast cell stabilizers, available as inhalers for asthma, a nasal spray, and eye drops, decrease the amount of histamine and other “allergic mediator” chemicals liberated.