Drugs Used in Allergy

September 28, 2009 by admin  
Filed under Medicine

allergy_drugAlien asked:

The word ‘allergic’ is often used loosely and has become almost a part of our general conversation. In a way it has become synonymous with ‘dislike’. Many ailments which cannot be immediately diagnosed are incorrectly attributed to allergy. Infact, allergy is an unusual response of the body caused by substances like foods, pollens, house dust, feathers, fungus, insecticides, drugs, and chronic infection.

The common allergic diseases are allergic rhinitis and hay fever, and the common cause is pollen. Allergy is due to abnormal antibodies of the IgE type which are formed only in some -susceptible individuals. Normally the antibodies are supposed to be protective. But the abnormal antibodies are fixed on special allergic cells called mast cells and on coming into contact with an allergen such as a pollen, release chemical agents such as histamine, serotonin, and slow-reacting substances. The release of these substances produce symptoms of allergy characterized by a running nose, itching, rash, and breathing difficulty.

Treatment

The management of allergic reactions includes specific treatment aimed at removing the cause, blocking allergic reaction by immuno-therapy, and symptomatic treatment. Some examples of allergen-avoidance are stopping use of such drugs, installation of air filters in air conditioners, keeping pets out of living room and removing dust collecting furniture and carpets.

Specific Treatment

Specific treatment consists of removal of the offending agents. This is done by ‘allergen testing’. Various extracts of possible offending agents are available and these are injected into the skin to detect the causative agent. However, in most cases it is difficult to identify the causative agent, but if it is found, desensitization of the individual can be carried out by injecting its doses. It has been found that through desensitization, the abnormal antibodies, that is, the IgE antibodies, are reduced or completely abolished, and protective antibodies, that is, the IgG anibodies are developed.

Symptomatic Treatment

The aim of symptomatic treatment is to check the release or antagonize the action of released chemical mediators of allergic reactions. The most important of these chemical mediators is believed to be histamine. For this reason antihistaminics are employed in almost all cases of allergy. Sometimes decongestants are combined with antihistaminics to enhance effects. Only in extremely severe cases are corticosteroids used.

Uses of Antihistaminics

Besides their use in allergy, antihistaminics are useful for prophylaxis and treatment of motion (travel) sickness and vomiting during pregnancy or following radiation. They are beneficial in the symptomatic treatment of Parkinsonism but ineffective in bronchial asthma. They are quite often used to treat common cold. In this condition anti-cholinergic effects of these drugs afford symptomatic relief by decreasing secretions of nose and respiratory passages.

Adverse Effects: The most common adverse effects are drowsiness and sedation which interfere with daytime activity, mental alertness, and reflex actions. Other side-effects include giddiness, ringing in the ears, weariness, fatigue, loss of appetite, nausea, vomiting, rapid pulse, a slight fall in BP, constipation, abdominal pain, dryness of mouth, urinary hasitancy and blurring of vision. Very high doses may induce fever. These adverse effects are more common in elderly people.

Precautions

Alcohol is forbidden with these drugs as sedation of a dangerous level may occur.

Driving and operating any kind of machine should be avoided after taking these drugs as they cause drowsiness.

If taken after a meal, the intensity of side-effects can be minimized.

Drugs containing chlorcyclizine and meclizine which are also antihistaminic, should not be self used by a pregnant woman. These may cause some adverse effects on the foetus.

Ointments containing these drugs should not be used for a prolonged period; allergic reactions have been found to be more common on local application of these drugs. (At times these anti-allergic drugs, when taken orally or more commonly, when applied on the skin, may cause allergic reaction. Is this not a paradox?)

Other Drugs for Symptomatic Treatment

Ketotifen (Ketovent, Ketotif)

This drug stabilizes the cell membranes of mast cells and thus prevents the release of histamine. Besides having antihistaminic properties, it is useful in preventing an attack of asthma. It does, however, cause drowsiness, a dry mouth, dizziness, nausea and weight gain.

Cromolyn Sodium (Ifiral, Fintal)

Used as eye drops (2%) in allergic conjunctivitis, nasal spray (2%) in allergic rhinitis and metered dose inhaler (1 to 2 mg/puff) in bronchial asthma.

Nedocromil

This drug is used 2 puffs, twice a day, in place of cromolyn.

Topical steroids like flunisolide (SYNTARIS) and budesonide (BUDECORT) are nasal spray.

Non-Sedative Antihistaminics for Symptomatic Treatment

These new generation anti-allergic drugs do not reach the brain and do not produce sedation (cetirizine causes some sedation) which is common adverse effects of all the drugs available in this group. These are therefore used more widely. They do not impair psychomotor activities such as driving and do not enhance effects of alcohol or diazepam. They are useful in allergic rhinitis, allergic conjunctivitis, urticaria, drug allergies and atopic eczema. They are not effective in motion sickness, vertigo and should not be used in pregnancy. These agents are less effective than older drugs in common cold.

Decongestants Used in Symptomatic Treatment

These agents reduce the swelling of mucous membranes (shrinking effect) in allergic diseases by constricting small blood vessels. Some drugs are used by mouth such as pseudoephedrine (PSEUDAFED 60 mg tab) and phenylpropanolamine. The latter is rarely used alone.

Allergic Colds

August 12, 2009 by admin  
Filed under Medicine

coldallery
Nikhil Abraham asked:

Allergic rhinitis

Also known as hay fever , this condition refers to an allergy to pollen , dust , pets etc. which results in sneezing / running nose , nasal stuffiness , watery and itchy eyes.

In most cases, symptoms are mild and at the most are inconvenient . But if its severe and persists for extended periods of time , it is a cause of concern and needs to be treated.

If the allergy is due to pollen , symptoms are seen in particular seasons depending on when the plant in question flowers. Allergies to other things could be throughout the year.

Diagnosis is by clinical symptoms. Skin/ blood allergen testing can also be done to pinpoint the cause for the allergy.

Though the obvious preventive step is to avoid exposure to the offending agent , in most cases since its environmental, it just cannot be avoided. Regular cleaning of living spaces and personal effects minimizes exposure to allergens.

Medicines for treatment fall into the following categories :

Antihistamines – these control symptoms such as sneezing , watering and itchiness of eyes etc. Though the older ones are cause drowsiness , the newer generation antihistamines have minimal sedative effects and are safe. There are even antihistamine nasal sprays which take effect fairly quickly.

Decongestants – are often combined with antihistamines in tablet form or are available as nasal sprays. Though these provide instant relief from nasal stuffiness, it is wise not to use them for more than a couple of days since long term administration is known to cause adverse changes in the nasal skin lining. This is also due to preservatives added to the solution. Also, with repeated use , the response decreases till there is no effect ultimately.

Intra nasal steroids are very effective in the treatment of symptoms that are present for long periods.. It is administered locally and hence is safe for long term use.

Other drugs that influence the allergic reaction cascade such as cromolyn and leukotriene receptor antagonists are also useful but need to be taken on a regular basis.

Oral/ injectable steroids are rarely given keeping in mind their long term effects and are only prescribed for short periods when symptoms are very severe.

Immunotherapy is also an option for those whose symptoms are severe, uncontrolled by medication , or if other allergic conditions (eg. asthma, eczema ) begin to develop.

What Is Immunotherapy For Allergies? Part 1/2

July 26, 2009 by admin  
Filed under Medicine

immunotherapyEric Morgan asked:

Here are some basic answers to questions you may have regarding allergen immunotherapy, also known as “allergy shots.”

Allergen immunotherapy is a treatment designed to decrease nasal allergies (also known as allergic rhinitis), allergic asthma and reactions caused by insect stings. Specific allergens are identified through allergy testing, so the allergist first knows what is causing the allergy symptoms, in order to effectively treat them. After the culprit has been identified, allergen immunotherapy involves getting injections of increasing amounts of specific allergens over the course of several months.

Does Immunology Work?

Aside from decreasing allergy symptoms like sneezing, runny nose and congestion, Immunotherapy can help prevent the development of new allergies. In children, Immunotherapy can help prevent allergic rhinitis from progressing into asthma. Even after the treatments have stopped, allergen immunotherapy often leads to long-lasting relief of allergy symptoms.

Many studies have shown that immunotherapy is effective for the treatment of nasal allergies, for both adults and children. A review of 18 published studies involving nearly 800 patients concluded that immunotherapy is highly effective in the treatment of allergic rhinitis. An extensive review of immunotherapy as a treatment for allergic rhinitis in children, showed that the only treatment able to affect the natural cause of the disease is immunotherapy. Studies showing the effectiveness of immunotherapy suggest that roughly 8 out of 10 allergy patients benefit significantly from immunotherapy.

Immunotherapy may also prevent the onset of asthma, and a review of multiple studies showed that allergen immunotherapy is also an effective treatment for asthma. These studies have indicated that treatment with immunotherapy results in reduced symptoms of asthma and improved pulmonary functions, and at the same time, reduces the need for asthma medications.

For individuals with a previously demonstrated allergic susceptibility to insect stings, immunization with insect venom is an extremely effective treatment for preventing future allergic reactions. A review of nine published studies indicates that a course of immunotherapy is highly effective in the management of insect sting allergy. Immunology can be a great alternative if you have any of the following concerns:

Poor response to medications

Impractical or impossible to avoid the offending allergens

Negative medication side effects

Wanting to avoid long-term medications or reduce the cost of medications

Coexisting allergic rhinitis and asthma

Possible prevention of asthma in children

Individuals with allergic asthma

If Immunotherapy Works Why Doesn’t Everyone Do It?

People who have very light symptoms or have found an effective medication that eliminates symptoms, may not need immunotherapy. For others, the time and commitment involved in starting and undergoing immunotherapy can be seen as an obstacle, especially when looking for a “quick fix”. In time however, more and more patients are realizing that the long-term benefits of immunotherapy are much better than having to be on medications for the rest of their life.

Who Is a Good Candidate for Receiving Immunotherapy?

Immunotherapy is recommended for those with allergic asthma, allergic rhinitis (involving various nasal symptoms) and conjunctivitis, or stinging insect allergy. It may be the best option for those who have difficulty controlling symptoms through avoidance or medication. Other considerations are that you do not like the side effects of allergy medication, the allergy medications are inconvenient, or having to take multiple medications in order to control symptoms. Immunotherapy is not recommended for those with food allergies. The best treatment for severe food allergies is to strictly avoid the offending food. The decision to begin immunotherapy will be based on several factors including:

Length of allergy season and how severe symptoms are.

How well medications and/or environmental controls take care of the allergy symptoms.

Wanting to avoid long-term reliance on medication.

Immunotherapy will require a significant time commitment-are you willing to make the commitment to the therapy?

Cost: may vary depending on insurance coverage.

Will Insurance Pay For Immunology?

Most insurance companies and HMOs will pay for immunotherapy, especially if your primary care doctor refers you to an allergist and the allergist recommends immunotherapy as part of your treatment. Even patients with milder symptoms may be recommended immunotherapy to avoid worsening of symptoms, particularly if they cannot always avoid the things they are allergic to, such as a family pet, bee stings, or specific native plants.

Who Is a Good Candidate for receiving immunotherapy?

Immunotherapy is recommended for those with allergic asthma, allergic rhinitis (involving various nasal symptoms) and conjunctivitis, or stinging insect allergy. It may be the best option for those who have difficulty controlling symptoms through avoidance or medication. Other considerations are that you do not like the side effects of allergy medication, the allergy medications are inconvenient, or having to take multiple medications in order to control symptoms. Immunotherapy is not recommended for those with food allergies. The best treatment for severe food allergies is to strictly avoid the offending food. The decision to begin immunotherapy will be based on several factors including:

Length of allergy season and how severe symptoms are.

How well medications and/or environmental controls take care of the allergy symptoms.

Wanting to avoid long-term reliance on medication.

Immunotherapy will require a significant time commitment-are you willing to make the commitment to the therapy?

Cost: may vary depending on insurance coverage.

How Is the Treatment Administered?

A very small hypodermic syringe is used to inject commercial allergen extracts. The injections are usually at the site of the loose tissue over the back of the upper arm, between the shoulder and elbow. This area is the least painful site for injection as there are very few nerve endings. Injections are given under the skin (”subcutaneous”). When administered correctly, the injections should only be slightly uncomfortable. They are not usually painful, and are well tolerated by adults, teenagers and most children. You may be advised to take an antihistamine a few hours before each injection to reduce the likelihood of any local allergic reaction and other side effects.

Can Young Children Receive Immunotherapy?

Children over the age of 5 may be good candidates for the therapy. Very young child will likely have difficulty cooperating with the immunotherapy regimen. However, immunotherapy can be a good option for children in general. Studies suggest that immunotherapy treatments may prevent the development of new allergies in children, and may help prevent the development of asthma in children who have rhinitis.

Is There an Age Limit to Receiving Immunotherapy?

Not really. Anyone from age 5 on up may benefit from receiving immunotherapy. With elderly persons, consideration should be given to the overall health and chronic medical conditions (such as cardiac disease), which could potentially cause problems. However most healthy children and adults can benefit from Immunotherapy treatments.

Where Does the Immunotherapy Take Place?

Ideally, immunotherapy should always be given in the prescribing allergist/immunologist’s office/clinic. If this is not possible for some extenuating circumstance, your allergist/immunologist should provide the supervising physician with all needed information about your specific treatment. Either way, you must always be in the care of an appropriate medical professional, who is qualified to administer Immunotherapy.

Allergies And Snoring

June 20, 2009 by admin  
Filed under Medicine

Michael Brown asked:


The woman who divorced her noisy partner told her friends that she was allergic to his snoring. What she didn’t realize is that his snoring was due to allergies.

The trumpeting noise associated with snoring is generated by airflow trying to push its way through an obstructed airway. While snoring is not an illness, it can be symptomatic of other health conditions, even an allergic reaction.

Allergic rhinitis is a health condition in which the membrane lining the throat and nose become inflamed. The inflamed membrane lining creates an obstruction in the airway, which in turn causes snoring. This condition is usually triggered by an allergic reaction to an inhaled substance. Seasonal allergic rhinitis is also known as hay fever.

Seasonal allergic rhinitis is usually due to trees, grass and other plant pollens, and occurs mainly in spring and summer when pollen counts are high. Perennial allergic rhinitis lasts yearlong, and is generally caused by an allergy to mold spores, animal fur, feathers, dust mites or house dust.

The symptoms of allergic rhinitis are quite clear:

* Sneezing

* Blocked or runny nose

* Red, watery, itchy eyes

* Itchy, irritated nose

* Headache

* Nosebleeds (not common)

* Snoring

If you believe that you are suffering from an allergic reaction, but you’re not sure of the cause, your doctor can perform a skin ***** allergy test. However, such tests are not fully conclusive, as some allergens will avoid identification.

In the event that you’ve pinpointed the cause of your reaction and taken steps to avoid it, your symptoms should subside very rapidly without further treatment. Some allergens, like pollen, are virtually impossible to avoid. In this case it may be necessary to take an anti-allergy drug to find relief.

Anti-allergy drugs in the form of nasal spray often contain sodium cromoglicate, a substance that blocks the allergy. Nasal sprays can be used as decongestants, but long-term use is not recommended. Corticosteroid drugs are often prescribed for hay fever, although their effectiveness is not instantaneous. Oral antihistamines may be used along with a decongestant to relieve inflammation and itching.

If allergic rhinitis is a persistent problem, your doctor might suggest immunotherapy, a procedure that desensitizes the immune system. Immunotherapy patients are injected with a series of gradually increasing doses of the allergen, to encourage the body to accept the substance without reacting. While immunotherapy can be an effective treatment for some allergy sufferers, it can take as many as four years for the treatment to be completed, and it is not always successful.

If you feel your snoring problem is caused by allergic rhinitis, there are several treatments available to help alleviate the problem. Try avoiding obvious allergens like furry animals. Use pillows and quilts with synthetic stuffing rather than feathers or down. Cover your mattress with a mite proof membrane. Remove soft furnishings and clean regularly to prevent dust collecting. Avoid visiting areas with long or newly cut grass. Purchase a pollen filter for your car and a HEPA filter for your home.

By avoiding the causes, you allergic reactions should diminish, and your allergy-induced snoring can disappear altogether.