Allergy - How Antihistamines Work

For millions of us allergy sufferers, antihistamines ease the annoying discomfort accompanying allergic reactions. Being an allergy sufferer myself, through the decades I have taken both over-the-counter and prescription antihistamines, some of which have been discontinued. Allergic reaction symptoms include nasal congestion, sneezing, coughing, headache, and itching indicating sensitization to certain allergens such as pollen, mold, dust, or insect venom. Repeated exposure results in allergic reactions due to antigen-antibody interactions. First, antigens come into contact with lung, gastrointestinal tract, and/or skin tissue, and enter into the bloodstream. Next, mast cells and white blood cells misidentify these as invaders and inappropriately respond by releasing histamines causing tissue injury. The severity of the allergic reaction is directly proportional to the amount of histamine released. Histamines dilate small blood vessels and capillaries, but contract smooth muscles. Responses include decreased blood pressure, increased heart rate, difficulty breathing, constipation or diarrhea, heartburn and nausea, and proteins and fluids leaking from capillaries. Nasal mucous membrane capillaries leaking, result in nasal congestion. Skin capillaries leaking produce hives and swelling resulting in pain and itching. Thankfully all antihistamines block most of histamines effects by competing at histamine receptor sites thereby preventing them from producing an effect on the tissues. Antihistamine drugs prevent, but can't reverse, histamine responses. Some of the general uses of antihistamines include relief from nausea and vomiting, relief from motion sickness, and relief from coughs. Usually antihistamines are administered orally since they are well absorbed in the intestinal tract, or topically, although a few can be given intravenously. To maintain a therapeutic dose, these medicines are given two to four times per day because the liver rapidly metabolizes them. First generation antihistamines, which can be used interchangeably, include chloropheniramine (Chlortrimeton?), diphenhydramine (Benadryl?), and promethazine (Phenergan?). Some of the side effects include nose and mouth dryness, and drowsiness. Some antihistamines are also used as local anesthetics because they depress sensor nerve activity. When taking these antihistamines, it is advisable to not drive or perform hazardous tasks, and not to use alcohol or other drugs. Second generation antihistamines include cetirizine (Zyrtec?), and Loratidine (Claritin?), and third generation antihistamines include fexofenadine (Allegra?), claim to be more selective for histamine receptors and cause less drying or sedating. However, these are contraindicated in patients with hepatic dysfunction, and when taking certain antifungal, antibiotic, and serotonin release inhibitors due to unfortunate deaths. My personal experience with these antihistamines is I did not find the relief I needed. Because of the sedative effect, antihistamines are used in sleep aids like Nytol?, or Tylenol PM?. Because of the drying effect, antihistamines are found in over?the?counter skin ointments/sprays/creams, cold remedies, and cough syrups. However, people with hypertension, cardiovascular disease, urinary retention, increased intraocular pressure, narrow-angular glaucoma, peptic ulcer, or prostatic hypertrophy should not use antihistamines. They are also contraindicated in dehydrated children, nursing mothers, newborn or premature infants. Nonetheless, antihistamines are widely used successfully by millions. In conclusion, antihistamines work by providing us allergy sufferers much needed: relief. ? Debby Bolen I educate the public about a preventative-based healthy lifestyle and operate my own online business offering the best in whole food health and wellness products. The best method of achieving wellness and optimal weight is by eating healthy and exercising. I am a Registered Nurse. Your Health Issues Decrease Your Weight Article Source:http://EzineArticles.com/?expert=Debby_Bolen Allergy - Factors to Consider When Purchasing an Air-Purifier So you've taken the first step in the decision making process. You've decided to buy an air purifier for your home or office. That was the easy part. Now comes the more difficult chore of actually sifting through all the plethora of product information available on the scores of air purifiers available to you. There are many factors to consider when purchasing an air-purifier. This list of tips will perhaps make it easier for you make your final choice. Which technology? There are multiple technologies in air-purifiers available in the market. There are the mechanical HEPA filers, electronic ionizers, ozone filters, UV filters and gas phase filtration purifiers. No single technology purifier will be effective in removing all the pollutants. Your choice would depend on which type of pollutant you wish to eliminate from your environment. Your best bet would be to invest in a hybrid type air-purifier which is one which combines two or more technologies into a single unit. Consider the noise factor Some air purifiers, like the HEPA filter, due to a motorized fan make a fair amount of noise. Others are completely silent. How much noise are you willing to put up with? This is a personal preference. Do request a demonstration of the model you are purchasing to get an indication of the noise level. Individual air purifiers for each room? Which room would you like to place the purifier in? Or it the whole house that you would like to cover. You can choose between a central air-purifying unit or a portable (one room) unit. The former, as the name suggests cleans all the air in your home through that single unit. This is attached to a central heating or cooling unit of your home. Portable unit, on the other hand services a single room at a time and the main advantage is that is can be moved to another room as the need arises. These are generally found to be more effective. However, depending on the size of the room this may mean buying one or more units for each room. Replacement and maintenance costs Do consider the costs of running and maintaining the product you finally purchase. An expensive air-purifier may actually work out more economical in the long run as it may require less maintenance, like filer changes and servicing, and running costs. Some purifiers have expensive filters but they do not need to be changed that frequently. Filter change intervals vary and depend on the extent of use of the air-purifier and the level of pollution in the air. Do remember to include electricity consumption as part of the running costs!