Pharmacological Management of Asthma

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Pharmacological Management of Asthma

Asthma is a long-term disease of lungs caused by inflammation and narrowing of the airways. The symptoms of asthma include recurrent wheezing, breathlessness, chest tightness, and coughing. The number of people having the condition has been increasing all over the world, with the United States recording more than 30 million patients, both children, and adults. Asthma symptoms can be mild or severe, during exacerbation. The two types of medicine used in treating asthma are categorized as long-term and quick-relief medications. Before making a choice on the type of medication to be prescribed, various factors must be considered.

Albuterol inhaler is one of the preferred medications for asthma patients. It is a selective beta-2 adrenergic receptor agonist. Liquid Albuterol is inhaled by mouth using a jet nebulizer while an inhaler is used in case of powder or aerosol forms. However, it must be noted that Albuterol inhalation may cause some side effects. The recommended dose is between 90 and 180 mg; however, if the appropriate dosage regime is not followed, then the outcomes may be deleterious. Therefore, caregivers play a critical role in ensuring that patients administer the correct dosage.

Albuterol Inhalers and Its Correlation with Inadequate Dosing and Nursing Implications

Asthma is a long-term lung disease that results from inflammation and narrowing of the airways. Usually, the disease is characterized by recurrent wheezing, breathlessness, chest tightness, and coughing (National Health Services, 2016). Asthmatic patients cough mostly at night and early in the morning. Asthma is known to affect people of all ages; however, the disease usually starts during childhood. In the United States, for instance, the total number of people having asthma is estimated at over 25 million, with children accounting for nearly 7 million (National Institutes of Health, 2014). Therefore, it is vital to study pharmacological management of asthma using Albuterol inhalers, its association with inadequate dosing, and nursing implications.

Overview of Asthma

Asthma is an incurable chronic disease; therefore, the aim of treatment is often to control the disease. An appropriate control strategy results in the following: prevention of troublesome symptoms such as breathlessness and coughing, reduction of the need for quick-relief medications, and maintenance of lung function. Apart from that, asthma treatment is aimed to help the patient maintain normal sleep and activity and reduce the chances of attacks, which may hospitalization or prolonged treatment (National Institutes of Health, 2014).

The airways tubes that transport air from and to the lungs are inflamed in asthmatic individuals. Whenever inflammation occurs, the airways become swollen and very sensitive. Besides, they can react strongly whenever certain substances are inhaled. Such reactions lead to the tightening of the muscles around the airways, which eventually become narrower and thus reduce airflow to the lungs. Whenever the swelling worsens, the airways become narrower. Moreover, the airways’ cells can produce more mucus than normal, which further narrows the airways (National Institutes of Health, 2014).

Asthma symptoms can be mild and end on their own or after a course of treatment using appropriate medication. However, in some instances, asthma symptoms can worsen. Exacerbations occur when the symptoms of asthma intensify or attacks become more frequent (National Institutes of Health, 2014). Normally, it is important to treat symptoms when they first occur because this can prevent the worsening of the situation resulting in a severe attack. The latter may warrant emergency care or lead to fatality.

The diagnosis of asthma is made based on medical and family histories, physical exams as well as test results. Medical and family history of asthma and allergies focuses on whether a patient has asthma symptoms as well as the time and frequency of their occurrence. The doctor may also ask about the health conditions that can interfere with the management of the condition, such as reflux disease, psychological stress, runny nose or sinus infections. Physical exams include listening to the breath or checking for the signs of allergies, such as eczema (National Institutes of Health, 2014). Common allergens include dust mites, pollens, and animal fur. Other triggers may include cigarette smoke, gases, strong smells, cold air, and exercise (National Health Services, 2016). A caregiver rates asthma as intermittent, mild, moderate, or severe depending on the outcome of the test results. The level of severity determines the kind of treatment that a patient is prescribed.

There are two types of medicine are used in the treatment of asthma, namely medications for long-term control and quick-relief medicines. Normally, any caregiver considers many factors before prescribing asthma medicines for a given patient. Although asthma medicines can be in the form of pills, they are mostly taken using an inhaler. The inhaler helps take the medicine directly to the lungs (National Institutes of Health, 2014). Most asthma patients may require long-term medicines that prevent the onset of symptoms but may not provide quick relief. The preferred long-term control medicines for asthma are inhaled corticosteroids. The medicines provide long-term relief for the swelling and inflammation that causes the sensitivity of the airways.

Inhaled corticosteroids remain safe when taken according to the prescription. The medicines are not the same as illegal anabolic steroids, which some athletes take. Besides, inhaled corticosteroids are not habit-forming even when taken daily for a long time (National Institutes of Health, 2014). Even though inhaled corticosteroids have some side effects, their benefits outweigh them. A notable side effect of the medicines is mouth infection, also known as thrush. However, it can be prevented using a holding chamber or spacer, which cannot allow the medicine to land in the mouth or go down past the threat.

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Albuterol Oral Inhalation

Bronchodilators play a critical role when treating airways disorders. Indeed, these medications form the basis of current management of conditions such as COPD and are important in the management of symptomatic asthma. Bronchodilators cause direct relaxation of smooth muscle cells. The main classes of bronchodilators are beta-2 adrenoceptor agonists, xanthines, and muscarinic-receptor agonists. The inhaled route remains preferred because it reduces systemic effects. Inhaled short-acting beta-2 agonists, such as salbutamol (albuterol), levalbuterol, and terbutaline, are effective bronchodilators, which are considered most effective in treating asthma, irrespective of the patient’s age (Berbecaru-Iovan, Popescu & Berbecaru-Iovan, 2013).

Albuterol is helpful in preventing and treating wheezing, difficulty breathing, breathlessness, chest tightness, and coughing that result from lung infections such as chronic obstructive pulmonary disease (COPD) and asthma. Albuterol inhalation aerosol also prevents breathlessness when performing the exercise. The aerosol form of the inhalant is used by adults and children from the age of 4 years and above while the powder form can be used by children aged 12 months or more (U.S. National Library of Medicine, 2016). Albuterol belongs to bronchodilators, a group of medications that cause relaxation and opening of air passages to the lungs, thereby easing breathing.

Liquid albuterol is inhaled by the mouth using a jet nebulizer while an inhaler is used in the case of powder or aerosol forms. The aerosol and powdered forms of albuterol are administered every four to six hours and a maximum of 30 minutes before exercising (U.S. National Library of Medicine, 2016). By contrast, the nebulizer is administered 3 to 4 times each day. Each aerosol inhaler delivers between 60 and 200 inhalations according to the size, whereas each powdered form provides approximately 200 inhalations (U.S. National Library of Medicine, 2016).

There are special considerations that must be observed before using albuterol inhalation.

1. Firstly, a patient must inform the caregiver about his/her allergy to albuterol, its ingredients, or any other medication (U.S. National Library of Medicine, 2016). Besides, the patient needs to tell the caregiver about being allergic to milk proteins.
2. Secondly, a patient should tell the caregiver the prescription medicines, nutritional supplements, herbal products as well as vitamins that he/she is taking or plans to take (U.S. National Library of Medicine, 2016). Specifically, it is crucial to mention beta-blockers, inhaled medications for relaxing air passages, colds medications, antidepressants, and monoamine oxidase inhibitors. Information regarding such medications is necessary for determining the dose or keen monitoring of side effects.
3. Thirdly, a patient needs to tell the caregiver about an irregular heartbeat, increased blood pressure, heart disease, hypothyroidism, seizures, or diabetes. Information about pregnancy or plans to get pregnant and breastfeeding is also critical (U.S. National Library of Medicine, 2016).

Albuterol inhalation may lead to side effects such as nervousness, uncontrollable shaking of the body, headache, nausea, vomiting, cough, throat irritation, and back, bone, or muscle pain. Some side effects can become serious, namely chest pain, irregular, pounding or fast heartbeat, rash, itching, hives, and difficulty swallowing. Therefore, if a patent experiences them, he or she has to call a physician immediately. Other side effects are increased breathlessness, swelling on various parts of the body, and hoarseness (U.S. National Library of Medicine, 2016). Likewise, a patient should inform a poison center should there be a case of overdose because it can lead to seizures, nervousness, fast heartbeat, dry mouth, nausea, dizziness, loss of energy, excessive tiredness, and problems falling asleep (U.S. National Library of Medicine, 2016).

Mechanisms of Action

Albuterol is a selective beta-2 adrenergic receptor agonist (Cazzola, Calzetta & Matera, 2011). This class of drugs acts on 2 adrenergic receptors, causing relaxation of airway muscles and bronchodilation. Even though the smooth muscle of the bronchial three receives very little or no sympathetic innervations, they contain numerous 2-adrenergic receptors (U.S. Department of Health & Human Services, 2014). Once the receptors are stimulated, they activate the Gs adenylyl cyclic adenosine monophosphate pathway. thereby reducing the tone of smooth muscles. Similarly, 2-adrenergic receptor agonists increase the conductance of calcium ion (Ca2+) sensitive potassium ion (K+) through ion channels found in smooth airway muscles (U.S. Department of Health & Human Services, 2014). As a consequence, the membrane becomes hyperpolarized and relaxes.

Apart from the smooth bronchial muscle, beta2-adrenergic receptors are also found on other cell types of the airways. When beta2 adrenergic receptors are stimulated, they inhibit the function of inflammatory cells, such as basophils, neutrophils, mast cells, eosinophils as well as lymphocytes (U.S. Department of Health & Human Services, 2014). Cyclic intracellular adenosine monophosphate occurs following the stimulation of beta2-adrenergic receptors in the cells of the airways. In the end, a signaling cascade is activated, which obstructs the release of cytokines and inflammatory mediators.

Albuterol has a small alpha-adrenoceptor (AR) activity at correct doses and tends to be selective between beta-2 and beta-1 adrenoceptors (Cazzola, Page, Calzetta & Matera, 2012). Usually, albuterol is selective for beta-2 adrenoceptors. Therefore, it is not surprising that the potency of albuterol is almost equivalent to bronchi isolated from relaxing human and bronchodilator potency for individuals with asthma when compared with epinephrine from histamine-promoted contraction. Albuterol does not lead to a maximum response to histamine while epinephrine causes a significant reduction in vitro (Cazzola et al., 2012).

Albuterol is a bronchodilator is characterized by a longer duration of action and a smaller influence on heart rate and blood pressure compared with isoproterenol. Furthermore, while isoproterenol causes tachycardia that is comparable with bronchodilation, albuterol reportedly causes similar bronchodilation but with insignificant cardiovascular responses. The maximum time for the start of bronchodilation after inhalation is 15 minutes. However, it binds weakly to receptors and then quickly diffuses into microcirculation, which is responsible for the short-time action of 4-6 hours (Cazzola et al., 2012).

Pharmacodynamic Profiles of Albuterol

The pharmacological activity of albuterol is based on stimulation through beta-adrenergic receptors of the adenyl cyclase, which is the enzyme responsible for catalyzing the conversion of adenosine triphosphate (ATP) to cyclic adenosine monophosphate. As the level of cyclic adenosine monophosphate increases, the relaxation of smooth bronchial muscle and the inhibition of release of mediators of immediate hypersensitivity from cells, particularly mast cells, occur. Albuterol also stimulates the secretion of mucous and mucociliary transport that takes place in the respiratory tract. The effectiveness of the inhaled albuterol is felt only a few minutes after inhalation while the duration of action is often between four and six hours (U.S. Department of Health & Human Services, 2014).

Albuterol is associated with cardiovascular effects, which can be determined based on the changes in blood pressure, pulse rate, and symptoms changes. The effects can be reduced by the administration of the medication. Similarly, oral albuterol causes tonicity reduction, which is associated with pain relief, especially during pregnancy (U.S. Department of Health & Human Services, 2014). Metabolic effects, for instance, decreased concentrations of potassium in serum, are felt after taking nebulized albuterol; however, the effects are usually mild and temporary. Albuterol also has lipolytic effects and may lead to increased insulin and blood glucose through the stimulation of glycogenolysis as well as stimulatory activity of receptors found in pancreas cells (U.S. Department of Health & Human Services, 2014).

Summary of Clinical Studies on Pharmacodynamics Activities of Albuterol

Ratnayake, Taveras, Iverson, and Shore (2016) conducted an investigation comparing pharmacokinetics, pharmacodynamics, and tolerability of two types of albuterol inhaler drugs in children suffering from asthma. In this single-center randomized study conducted in children, the dosage for the two inhalers was set at 180 mg, with albuterol concentrations measured before and after the medicine intake to determine the primary pharmacokinetics value. Besides, blood pressure and heart rate were both monitored before and after the administration of the dose for pharmacodynamic effect. Notably, the two treatments had comparable pharmacodynamic parameters without serious adverse effects, mortality, or withdrawals. Therefore, the investigators concluded that a single dose of 180 mg was adequate in children (Ratnayake et al., 2016).

In another study, Kerwin et al. (2016) compared pharmacokinetics, pharmacodynamics, efficacy, safety, and extrapulmonary pharmacodynamics of albuterol delivered through a hydrofluoroalkane (HFA) with the trademark name of ProAir®, a metered-dose inhaler as well as a multi-dose dry-powder inhaler (MDI) (Kerwin et al., 2016). The randomized double-blind multicenter and placebo studies were conducted in persistent asthma patients, with adult patients in the first study and patients aged 12 years and above in the second one. The study participants received albuterol dosages between 90 and 180 mg (Kerwin et al., 2016). Importantly, the investigators concluded that the two medications had similar efficacy, pharmacodynamic and pharmacokinetic profiles, and were well tolerated at doses between 90 and 180 mg.

The use of inhaler devices is straightforward and not likely to cause medication errors, patient dissatisfaction, or lack of adherence. However, incorrect use of these devices incurs the risk of adverse clinical outcomes (Welch, 2016). Therefore, it is important that asthma patients use inhaler devices according to prescription.

Potential Adverse Effects of Albuterol Inhalation Use in Patients

Albuterol remains the preferred therapy for individuals suffering from acute asthma exacerbations. Some of the mild adverse effects that have been associated with increased dosing of albuterol include tremor, headache, and tachycardia (Adams, Sutter & Albertson, 2011). Tremors have been reported in cases where albuterol is administered at high doses using a nebulizer. Other side effects include hypokalemia, which is associated with intracellular shifting of potassium, arrhythmias due to high dosing, and lactic acidosis in rare cases (Adams et al., 2011).

Additionally, Takotsubo cardiomyopathy (TCM) is a cardiac condition caused by acute stress (Patel, Assad, Wiemann & Zughaib, 2014). TCM is characterized by apical ballooning and broken heart syndromes. Individuals suffering from this condition present with chest pain that mimics acute myocardial infarction. Beta-2 agonists such as albuterol lose their selectivity when applied at higher doses and may contribute to TCM. Specifically, patients with asthma exacerbations are likely to develop TCM due to the overuse of beta-2 agonists (Patel et al., 2014).

Inadequate Dosing and Nursing Implications

The adequate dosing for albuterol is usually between 90 and 180 mg (Ratnayake et al., 2016; Kerwin et al., 2016). When asthma exacerbation is mild, albuterol can be administered using a spacer. The number of puffs would range between four and eight that will be delivered every 20 minutes with up to 3 doses given in the first hour in children while in adults the puffs would be delivered every 20 minutes for up to four hours (Adams et al., 2011). However, a number of factors can cause inadequate dosing and subsequent adverse effects of medicine.

1. Firstly, the type of nebulizer used can affect dosing (Ari, Fink & Dhand, 2012). The variability of aerosol output in jet nebulizers decreases efficiency. Thus, output characteristics vary significantly in terms of drugs delivered and nebulization time.
2. Secondly, the quantity of medication that remains in the nebulizer when the end of treatment will always vary, with jet nebulizers having more residual volume (Ari et al., 2012). The higher the residual volume the less nebulization of medication occurs and the higher the chance of delivering inadequate medication dosage.
3. Thirdly, alteration of the flow of gas is likely to increase particle size and reduce drug delivery to the pulmonary (Ari et al., 2012). Reducing gas flow leads to a corresponding increase in the time of nebulization to the lungs. Consequently, there is a need for careful attention when performing nebulization to ensure that medication is delivered appropriately and inadequate doses are avoided.

Inadequate dosing will increase the exact cost of nursing practice in terms of human suffering as well as the added cost of healthcare. Asthma patients will continue to suffer if they are administrated the wrong dosage. Similarly, healthcare costs increase, particularly if adverse effects are resulting from inadequate dosage (Cheragi, Manoocheri, Mohammadnejad & Ehsani, 2013).

Nurses may have to deal with the emotional impact that follows inadequate dosing. Apparently, there are numerous psychological outcomes that may occur due to inadequate dosing. Some of the psychological effects include self-blame, doubt, anxiety, loss of confidence, guilt, embarrassment, and remorse. Such outcomes may hinder the healing process or lead to hospital admission (Cheragi et al., 2013).

Finally, inadequate dosing may expose nursing providers to legal consequences, such as criminal prosecution, probation, suspension, or even termination. Nursing professionals may be liable for prosecution, which further lowers morale in care providers who could be feeling overworked already (Cheragi et al., 2013).

Conclusion

Asthma is a chronic disease that is associated with the inflammation and narrowing of the airways. Symptoms of asthma include recurrent wheezing, breathlessness, chest tightness, and coughing. Since a growing number of people continue to suffer from the condition all over the world, there is a need for novel medications for alleviating the condition. It is important to recognize that there is no cure for this condition; however, there are medications that can relieve its symptoms.

Inhaled Albuterol, which is currently the preferred medication for asthma, has many disadvantages, namely, it is characterized by various side effects and the possibility of inadequate dosing. However, the condition can be resolved if the medication is applied appropriately. Importantly, the correct dosage of Albuterol varies between 90 and 180 mg. Inadequate dosing may cause adverse health consequences to patients and have practical implications for nursing caregivers. Therefore, it is vital to consider the correct dosage and the right way to deliver medicine.