Breathing difficulty can be a distressing situation to combat and a major diagnostic challenge for the physicians. One of the most prevalent and significant cause of breathing difficulty is asthma.<\/p>\n
Asthma<\/a> is an inflammatory condition of the airway, characterized by hyper-responsiveness of the airway to certain trigger factors. These trigger factors can be anything from dust, pollen, cold air, tobacco smoke to physical activity like exercising. Asthma is also marked by an excessive mucous production by cells of the airway. Swelling, increased bronchial responsiveness and excess mucous production, leads to narrowing of the airways, causing episodes of breathing discomfort.<\/p>\n It is a life-long condition with no particular cure. However, asthma can be effectively managed through medications.<\/p>\n Some classic symptoms of asthma are as follows:<\/p>\n When the symptoms of asthma worsen, the patient is said to suffer an \u201casthma attack\u201d or an \u201casthma flare-up\u201d. Medically, this condition is known as \u201cStatus Asthmaticus\u201d. It is an acute severe condition which is considered a medical emergency. It is a fatal condition requiring immediate medical intervention.<\/p>\n There is no cure for asthma. Prevention and symptomatic relief are the goals of treatment. Treatment depends on the patient’s age, type of asthma<\/a> and severity of the condition. Recognizing the trigger factors and their avoidance is the first step in preventing asthma attacks.<\/p>\n However, drug therapy is required in almost all the patients. Most of these drugs are available on prescription and are dispensed in drug-delivery devices, i.e. inhalers or nebulizers.<\/p>\n Earlier, some over the counter medications were available for asthma. These included combination tablets of ephedrine and guaifenesin, racepinephrine inhaler and CFC containing epinephrine inhalers. However, later it was realized that these drugs may mask symptoms of some debilitating conditions like cardiovascular conditions<\/strong>. Also, FDA has revoked CFC containing inhalers from the market, considering the environmental hazard (i.e. ozone depletion) posed by it. Therefore, doctors strictly condemn the use of over the counter medications for relieving asthma.<\/p>\n Most advocated treatment of asthma include corticosteroids, beta-2 adrenergic agonist, anti-cholinergics, mast cell stabilizers, leukotriene modifiers, theophylline and anti-IgE antibody. Acute onset of asthma necessitates the use of quick-relief medications. Once patient is stabilized, long-term medications are prescribed to prevent onset of future episodes.<\/p>\n The drugs used in asthma are described below.<\/p>\n These are the mainstay in the treatment of asthma. These are taken on a daily basis to prevent the onset of asthma i.e. a patient is supposed to take these medications even after the symptoms have resolved. Various drugs advocated in long-term control therapy are listed below.<\/p>\n Corticosteroids are steroid hormones which are produced by the adrenal glands in our body. This group of steroids is of two types namely mineralocorticoids and glucocorticoids. Both of these types have anti-inflammatory properties due to which these are used to treat various diseases. Mineralocorticoids have no therapeutic benefit in asthma whereas Glucocorticoids are potent anti-inflammatory drugs and are very useful in asthma. They suppress the hyper-responsiveness of the bronchi and reduce the inflammation of the airway, thus providing relief in asthma. For long-term control of chronic asthma, inhalation steroids are used as a first-line drug. Oral steroids are used when patient is not responding to inhaled steroids.<\/p>\n Available as:<\/strong> Aerosol preparation in metered dose inhalers (MDIs) and dry powder inhalers (DPIs) as well as oral preparations<\/p>\n A. Beclomethasone dipropionate<\/strong> B. Mometasone<\/strong> A. Budesonide<\/strong> A. Prednisolone<\/strong> B. Hydrocortisone<\/strong> C. Dexamethasone<\/strong> Oral Corticosteroids are also used in treatment of other diseases, such as allergic diseases, arthritis, etc.<\/p>\n This group of drugs stimulates the \u03b2-2 adrenergic receptors which are present in the bronchi of the respiratory system. These receptors when stimulated, relax the muscles of the bronchi and cause bronchodilation i.e. dilation or expansion of the airways. These drugs are most effective when inhaled. However, research has shown that regular use of these drugs may worsen asthma. Therefore, it is recommended that patients requiring long-term use of this drug should combine it with inhaled steroids.<\/p>\n Available as:<\/strong> Aerosol preparation in metered dose inhalers (MDIs) and dry powder inhalers (DPIs)<\/p>\n A. Salmeterol<\/strong> A. Formoterol<\/strong> Long-acting \u03b2-2 Adrenergic Agonist are also used in the treatment of other respiratory disorders, such as COPD.<\/p>\n Cysteinyl Leukotrienes (CysLT) are inflammatory mediators which are released by inflammatory cells of the body, such as mast cells, macrophages, eosinophils in response to a trigger factor. These mediators are produced in asthma and are responsible for several biological consequences such as constriction of bronchi, increased secretion of mucous and hyper-responsiveness of bronchi.<\/p>\n Leukotriene modifiers stop the action of CysLT and thus help in dilation of bronchi, reduce mucous secretion and decrease the responsiveness of bronchi, thereby relieving inflammation of airway.<\/p>\n Available as:<\/strong> Oral preparations<\/p>\n A. Montelukast<\/strong> B. Zafirlukast<\/strong> C. Zileuton<\/strong> When the body of an asthma patient is exposed to an allergen or a trigger factor, inflammatory cells such as mast cells activate. These cells release a chemical called histamine which acts as an inflammatory mediator and produces symptoms of asthma. Theophylline and its compounds belong to methylxanthines class of drugs. They reduce the release of histamine from inflammatory cells, thus are beneficial in asthma. They also promote the clearance of excess mucous and causes bronchodilation.<\/p>\n Available as:<\/strong> Oral preparations<\/p>\n A. Theophylline<\/strong> Theophylline is also used in the treatment of bronchitis<\/a>, emphysema<\/a> and other breathing disorders. Injectable preparations of theophylline have been discontinued, as per FDA instructions.<\/p>\n This group of drugs stabilizes the mast cells and prevents their degranulation i.e. it prevents the release of inflammatory mediators from mast cells, thus preventing the onset of asthma.<\/p>\n Available as:<\/strong> Oral preparations and aerosol preparations.<\/p>\n A. Ketotifen Oral<\/strong> However, oral ketotifen is being used for asthma in Canada, Europe and Mexico. Also, FDA approved the use of ocular administration of ketotifen ophthalmic in US for conjunctivitis and it is available as an over the counter formulation, such as eye drop.<\/p>\n A. Sodium Cromoglycate<\/strong> B. Nedocromil Sodium<\/strong> Sodium cromolycate and nedocromil inhalers contain a CFC containing propellant, which is an environmental hazard. Hence, FDA has phased out these inhalers. However, in line with the Montreal Protocol (an international agreement to ban CFC), new inhalers containing HFA propellant were developed. But, these are available in UK and Australia only, and are not sold in US.<\/p>\n Hence, nedocromil formulations are completely discontinued and nebulized solutions of cromolyn are the only remaining formulations, which can be used.<\/p>\n When the body is exposed to an allergen, immunoglobulin E (IgE) binds to the surface of mast cells and facilitates the release of inflammatory mediators which aggravate asthma. Anti-IgE antibodies are monoclonal antibodies, which do not act on any inflammatory cell, instead neutralize the free circulating IgE, thus preventing the onset of asthma.<\/p>\n Available as:<\/strong> Subcutaneous injection<\/p>\n A. Omalizumab<\/strong> Omalizumab is being tried in other allergic diseases as well.<\/p>\n Bronchial smooth muscles consist of a particular receptor, called as muscarinic receptors, which cause constriction of bronchi. Anti-cholinergic used in asthma inhibits these receptors, thus cause dilation of bronchi.<\/p>\n Available as:<\/strong> Aerosol preparation in metered dose inhalers and in inhalation sprays<\/p>\n A. Ipratropium bromide<\/strong> B. Tiotropium bromide<\/strong> Anticholinergics are chief bronchodilators used in the treatment of COPD.<\/p>\n These are also known as rescue medications. These are used in an acute episode of asthma, medically known as Status Asthmaticus. Various drugs which effectively relieve bronchospasm in an acute asthma attack are listed below.<\/p>\n The mechanism of action is similar to long-acting \u03b2-2 Adrenergic Agonist. These act for a shorter period of time and are taken through inhalation route in acute attacks of asthma.<\/p>\n Available as:<\/strong> Oral preparations and Aerosol preparations in metered device (inhaler or nebulizer)<\/p>\n A. Terbutaline<\/strong> B. Albuterol<\/strong> A. Albuterol<\/strong> B. Terbutaline<\/strong> Earlier, terbutaline was available over the counter and was used by many pregnant women to prevent recurrent preterm labor. It was found that terbutaline lead to major cardiovascular events and maternal deaths. Hence, FDA has disapproved the off-label use of terbutaline for acute obstetric cases, including treatment of uterine hyperstimulation and preterm labor.<\/p>\n The mechanism of action of steroids in asthma has already been mentioned in the previous section. However, in an acute attack, injections in the veins are administered as it relieves the bronchoconstriction in lesser time. Once the patient is stabilized, oral steroid therapy is started.<\/p>\n Available as:<\/strong> Injectable preparations<\/p>\n A. Hydrocortisone<\/strong> B. Triamcinolone<\/strong> The acting mechanism of anti-cholinergic and \u03b2-2 Adrenergic Agonist has already been stated previously. In an acute attack of asthma, both these group of drugs are combined to produce effective results.<\/p>\n Available as:<\/strong> Aerosol preparations<\/p>\n Albuterol sulfate\/Ipratropium bromide<\/strong> The above-mentioned drugs are the chief drugs used in the treatment of asthma. However, there are certain other drugs, which may be added to the conventional treatment. These are described below.<\/p>\n It is a pressor agent, belonging to a class of drugs, known as adrenergic drugs. It is an alkaloid, derived from Ephedra vulgaris. It acts on certain receptors, called as alpha and beta-adrenergic receptors, present in various organs of our body, including bronchi. By stimulating these receptors, ephedrine causes bronchodilation, thus preventing the onset of asthma attacks and providing symptomatic relief.Symptoms<\/h2>\n
\n
Treatment<\/h2>\n
1. Long-term Control Medications<\/h2>\n
I. Oral and Inhalation Corticosteroids<\/h3>\n
Aerosol preparation in MDIs<\/h4>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> beclomethasone dipropionate
\nBrand name:<\/strong> Qvar inhaler
\nCommon side-effects:<\/strong> Nausea, stomach upset, vomiting, sore throat, headache, cough, unpleasant taste in mouth, dryness in mouth\/throat\/nose after use, deepened voice, hoarseness.
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Present (As Ethanol in propellant)<\/p>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> mometasone inhalation
\nBrand name:<\/strong> Asmanex HFA
\nCommon side-effects:<\/strong> cough, body aches, congestion, cold or flu-like symptoms, dryness or soreness of the throat
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Present (As Ethanol in propellant)<\/p>\nDry Powder Inhalation in DPIs<\/h4>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> budesonide inhalation powder
\nBrand name:<\/strong> Pulmicort Turbuhaler
\nCommon side-effects:<\/strong> Ear ache, fever, diarrhea, pain while urinating, lower abdominal pain, nausea, redness or discharge from the eye, eyelid or lining of eye, trouble swallowing, sore throat, shortness of breath, vomiting, vaginal itching and discharge
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Absent<\/p>\nOral steroids<\/h4>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> prednisolone
\nBrand name:<\/strong> Prelone
\nSide-effects:<\/strong> Heartburn infections, insomnia, dizziness, headache, nausea
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Absent<\/p>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> hydrocortisone
\nBrand name:<\/strong> Cortef
\nSide-effects:<\/strong> Blurred vision, anxiety, aggression, dry mouth, dizziness, decrease amount of urine, irritability, pounding irregular heartbeat, headache, mood changes, mental depression, trembling, restlessness, weight gain, trouble sleeping
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Absent<\/p>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> dexamethasone
\nBrand name:<\/strong> Baycadron
\nSide-effects:<\/strong> Agitation, aggression, blurred vision, anxiety, irritability, headache, mood changes, shortness of breath, weight gain, trouble thinking, walking, sleeping
\nIndicated in Pregnancy:<\/strong> Indicated only for short-term use
\nAlcohol Content:<\/strong> Absent<\/p>\nII. Long-acting \u03b2-2 Adrenergic Agonist<\/h3>\n
Aerosol preparation in MDIs<\/h4>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> salmeterol xinafoate
\nBrand name:<\/strong> Serevent
\nSide-effects:<\/strong> Headache, cough with mucous, throat irritation, difficulty with breathing, runny nose, stuffy nose, sneezing, wheezing, chest tightness
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Absent<\/p>\nDry Powder Inhalation in DPIs<\/h4>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> formoterol inhalation powder
\nBrand name:<\/strong> Foradil Aerolizer
\nSide-effects:<\/strong> Cold or flu-like symptoms, chills, body aches, headache, ear congestion, fever, cough, hoarseness, difficulty in breathing, nasal congestion, sore throat, loss of voice, runny nose, sneezing
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Absent<\/p>\nIII. Leukotriene Modifiers<\/h3>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> montelukast sodium
\nBrand name:<\/strong> Singulair
\nSide-effects:<\/strong> Headache, flu-like symptoms, bloody nose, stomach pain, breathing discomfort, sweating, joint pain, tenderness or pain around cheekbones and eyes, chest tightness, trouble with swallowing
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Absent<\/p>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> zafirlukast
\nBrand name:<\/strong> Accolate
\nSide-effects:<\/strong> Fever, chils, hoarseness of voice, cough, lower back or side pain, painful urination
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Absent<\/p>\n
\nUS-FDA Status<\/strong>: Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> zileuton
\nBrand name:<\/strong> Zyflo
\nSide-effects:<\/strong> Nausea, fever, headache, cough, runny or stuffy nose, upset stomach, pain around cheekbones and eyes, wheezing, chest tightness, troubled breathing
\nIndicated in Pregnancy:<\/strong> Use only when absolutely indicated
\nAlcohol Content:<\/strong> Absent<\/p>\nIV. Methylxanthines<\/h3>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> theophylline oral
\nBrand name:<\/strong> Theo-24
\nSide-effects:<\/strong> Fainting, chest pain, slow, paving or irregular heartbeat, persistent vomiting, increase in urine volume, seizures, light-headedness, trembling, rapid pulse
\nIndicated in Pregnancy:<\/strong> Safe during second and third trimester. However, risk during first trimester has not been completely ruled out
\nAlcohol Content:<\/strong> Absent<\/p>\nV. Mast Cell Stabilizers<\/h3>\n
Oral Preparation<\/h4>\n
\nUS-FDA Status:<\/strong> Not Approved for Asthma
\nGeneric name:<\/strong> ketotifen
\nBrand name:<\/strong> Asthafen
\nSide-effects:<\/strong> Dizziness, blurred vision, severe drowsiness
\nIndicated in Pregnancy:<\/strong> No
\nAlcohol Content:<\/strong> Absent<\/p>\nAerosol preparation (inhaler or nebulizer)<\/h4>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> cromolyn Inhalation Solution (nebulizer)
\nBrand name:<\/strong> Intal Nebulizer solution
\nSide-effects:<\/strong> Diarrhea, headache, muscle pain, irritability, nausea. Abdominal pain.
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Absent<\/p>\n
\nUS-FDA Status:<\/strong> Not approved
\nGeneric name:<\/strong> nedocromil sodium
\nBrand name:<\/strong> Tilade inhaler
\nSide-effects:<\/strong> Body ache, cough, abdominal pain
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Absent<\/p>\nVI. Anti-IgE Antibody<\/h3>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> omalizumab
\nBrand name:<\/strong> Xolair injection
\nSide-effects:<\/strong> Chills, blistering, body aches, fever, bleeding, congestion, leg pain, hoarseness, itching, lumps, muscle or joint pain, numbness, sore throat, runny nose, redness, tenderness in cheekbones and eyes
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Absent<\/p>\nVII. Anticholinergics<\/h3>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> ipratropium bromide
\nBrand name:<\/strong> Atrovent HFA
\nSide-effects:<\/strong> Bloody or cloudy urine, cough with mucous, bladder pain, increased urge to urinate, painful urination, shortness of breath, chest tightness.
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Present (In propellant)<\/p>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> tiotropium inhalation spray
\nBrand name:<\/strong> spiriva respimat
\nSide-effects:<\/strong> chest heaviness, sweating, nausea, irregular or fast heartbeat, breathing discomfort, pain in arm, jaw or back.
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Absent<\/p>\n2. Quick Relief Medications<\/h2>\n
I. Short-acting \u03b2-2 Adrenergic Agonist<\/h3>\n
Oral preparations<\/h4>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> terbutaline oral
\nBrand name:<\/strong> Brethine
\nSide-effects:<\/strong> Trembling in hands, feet, arms and leg, headache, sweating, light headedness
\nIndicated in Pregnancy:<\/strong> No
\nAlcohol Content:<\/strong> Absent<\/p>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> albuterol sulfate
\nBrand name:<\/strong> Vospire ER
\nSide-effects:<\/strong> Trembling in hands, arms, feet, legs and pounding heartbeat and pulse
\nIndicated in Pregnancy:<\/strong> No
\nAlcohol Content:<\/strong> Absent<\/p>\nAerosol preparations<\/h4>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> albuterol
\nBrand name:<\/strong> Proventil-HFA
\nSide-effects:<\/strong> Trembling in hands, arms, feet, legs and pounding heartbeat and pulse
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Present (As ethanol in propellant)<\/p>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> terbutaline nebulizer
\nBrand name:<\/strong> Bricanyl
\nSide-effects:<\/strong> Trembling in hands, feet, arms and leg, headache, sweating, light headedness.
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Absent<\/p>\nII. Intravenous Corticosteroids<\/h3>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> hydrocortisone sodium succinate
\nBrand name:<\/strong> Solu-Cortef
\nSide-effects:<\/strong> Blurred vision, anxiety, aggression, dry mouth, dizziness, headache, irritability, depression, mood changes, dizziness, decreased amount of urine
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Absent<\/p>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> triamcinolone hexacetonide
\nBrand name:<\/strong> Aristospan
\nSide-effects:<\/strong> Anxiety, blurred vision, aggression, noisy rattling breathing, irritability, shortness of breath, headache, mental depression, dizziness
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Absent<\/p>\nIII. Combination of Anti-cholinergic and \u03b2-2 Adrenergic Agonist<\/h3>\n
\nUS-FDA Status:<\/strong> Approved for Asthma
\nAvailability:<\/strong> Prescription only
\nGeneric name:<\/strong> ipratropium bromide and albuterol sulfate
\nBrand name:<\/strong> Combivent respimat inhalation spray
\nSide-effects:<\/strong> Cough with mucous, body aches, chills, headache, fever, loss of voice, sore throat, runny or stuffy nose, sneezing, chest tightness, breathing difficulty.
\nIndicated in Pregnancy:<\/strong> Yes
\nAlcohol Content:<\/strong> Absent<\/p>\nOther Drugs Used<\/h2>\n
1. Ephedrine<\/h3>\n