The Role of Albuterol in Emergency Medicine

Commonly known as Ventolin or albuterol, Salbutamol is a common short-acting beta-agonist used in the treatment of common pulmonary diseases. It is also applicable in the management of elevated blood potassium. Although commonly used in inhaler and nebulizer form, the drugs are also available in pills and intravenous form. While Ventolin is the common trade name for the drug, Proventil is also used. The chemical name for the drug is 1-(-4-hydroxy-3-hydroxmethylphenyl)-2-(t-butylamino)-ethanol sulfate ((C13H21NO3)2H2SO4) (Mojtaba et al. 2016). Salbutamol and albuterol are the generic names. The Salbutamol is my very first drug to know as one of my cousin who suffered recurrent obstructive lungs diseases used it when I was a child. I had also seen many people use it when they had severe asthma attacks and I think it is a life-saving drug. It is usually prescribed on as needed basis when there are acute attacks mainly to relieve symptoms before full medical attention is provided to a patient. The drug was first made in the UK in 1967 and commercialized in 1969, and its use spread across the world from this point (Hautmann et al., 2013). However, its use did not become significant until in the 1980’s.

Relevance to a Paramedic

Ventolin is one of the most important drugs that a paramedics should familiarize themselves with. The drug is fast acting and used to relieve acute symptoms of attack quickly. It’s availability in many forms also allows usage with alternative methods of administration in case one route is compromised. For example, if there is extreme shortness of breath or the airway is completely blocked, the drug can be administered intravenous (Li, Xie, Li & Yu, 2014). Finally, the drug can also be used for other areas involving relaxation of smooth muscles such as relaxing uterine muscles to delay premature labor in case other drugs are absent. The drugs are also highly correlated and hence safe dosage can easily be given.

Classification of the Drug

Salbutamol is plant-based drug with the active component derived from the bark of some trees. Salbutamol is absorbed differently depending on the method used in administration. Inhaled drug enters directly into smooth muscle cells of the lungs through active diffusion where it exerts action. On the other hand, that injected into the blood is transported to the smooth muscles then gets into muscles by facilitated diffusion. The ingested drug is absorbed into the blood stream though facilitated diffusion then carried through blood. The active component of the drug is albuterol sulfate, a beta 2-adrenergic bronchodilator which is highly selective (McCabe, Koppenhagen, Blair & Zeng, 2012). Consequently, it is used primarily in the treatment of pulmonary system-related complication. However, it has also been used for relaxation of uterine muscles to delay premature delivery before calcium blockers were applied. The drug belongs to the beta 2 adrenergic agonist group that can mimic the activity of normal body catecholamines like dopamine, epinephrine, and norepinephrine (Li et al., 2014). These beta 2-adrenergic agonists act on smooth muscles of the uterus, intestines and bronchial trees vasculature. When taken for the purpose of pulmonary system treatment, albuterol stimulates the beta 2-androgenic receptors in lungs hence activating the enzyme adenylate cyclase. The activated enzyme catalyzes the conversion of adenosine triphosphate (ATP) to cyclic-3’,5’-adenosine monophosphate (cAMP) (Mojtaba et al. 2016). The increase in the amount of cAMP leads to relaxation of bronchial smooth muscles and relive bronchospasms. Salbutamol is a quick action drug whose peak blood concentration occurs for approximately 3 hours and is completely excreted in three days. The drug is broken down in the liver and excreted in the form of salbutamol 4’-phosphate through blood and faeces. The drug can be administered in the body through inhalation, intravenous, intramuscular and oral routes. The oral route can be in the tablet or syrup form. Dosages of the drug depend on the manner in which it is being administered.

Target Population

Salbutamol is a drug used by the general population from the age of four years. However, recent studies show that the drug can be used for children above the age of two years. The target population for this drug is hence all individuals of the age of 4 years and above who have recurrent pulmonary disease problems such as asthma, chronic obstructive pulmonary disease, and exercise-induced bronchoconstriction. However, the drug is contraindicated for pregnant and nursing mothers. In pregnancy, it should only be used only when it is absolutely necessary. This is due to recent studies that show that 10% of salbutamol in mother’s blood gets into the fetus (Li et al., 2014). Also, it has been suspected that unknown concentration of the drug is excreted in milk. Although adverse effects on babies have not been reported, the risk is mitigated. Also, recommendations require the drug to be cautiously used among geriatric patients.

Mechanism of Action

Generally, Ventolin is a common muscle relaxant that only acts on smooth muscles. One in the bloodstream, Ventolin gets into the cells of muscles that are inflamed and stimulate the release of an enzyme that converts the high-energy molecule, ATP to CAMP (Price, Rigazio, Small & Ferro, 2016). This action is caused by the stimulation of beta-2 adrenergic receptors and hence activate the enzyme adenylate cyclase. The enzyme causes the energy rich molecule ATP in the cell to be converted to Camp hence reducing the amount of energy available to the smooth muscle cells (McCabe et al., 2012). The lack of energy causes the smooth muscle cells not to stretch due to lack of relaxing. The muscle tissue hence becomes flaccid, and the whole muscle relaxes causing the airways to open. Ones open, air can freely move in and out of the lungs, and the patient is recovering. However, the effect of the drug can only be felt for a limited amount of time, and hence the patient should not predispose himself to factors that may cause recurrence.

Effectiveness of the Drug

Most clinical control trials have shown Ventolin to have a significant effect on respiratory tract in the form of relation than other drugs. However, inhalation is the most effective method of administering the drug (McCabe et al., 2012). There are two reasons for this conclusion; the effect is fast and results in minimum systemic levels. The average response time for bronchial unblocking using the inhalation route of administration is 1.2minutes (Price, Rigazio, Small & Ferro, 2016). The most ineffective method for administration of the drug is oral in the form of tablets which take more than five minutes for the effects to be seen. The mean difference between inhaled and oral Ventolin administration is 15% (Mojtaba et al. 2016). This makes it the most valuable lifesaver for among the other decongestant.

Conclusion

Ventolin is one of the drugs a paramedic should not leave behind in all his escapades. With the high number of uses, its proven effective and life-saving capacity, the drug is one of the best developed.

References

Hautmann, J., Godoy, S. E., Marshik, P., Chand, R., McConville, J., Krishna, S. & Muttil, P. (2013). Effect of time between actuation on the dose variability for three metered dose inhalers. Respir Drug Deliv Eur, 2, 429-434.
Li, J. S., Xie, Y., Li, S. Y., & Yu, X. Q. (2014). Comparison of conventional medicine, TCM treatment, and combination of both conventional medicine and TCM treatment for patients with chronic obstructive pulmonary disease: study protocol of a randomized comparative effectiveness research trial. Trials, 15(1), 153.
McCabe, J. C., Koppenhagen, F., Blair, J., & Zeng, X. M. (2012). ProAir® HFA delivers warmer, lower-impact, longer-duration plumes containing higher fine particle dose than Ventolin® HFA. Journal of aerosol medicine and pulmonary drug delivery, 25(2), 104-109.
Mojtaba, K. A., Fardin, A., Naghi, K. S. A., Koorosh, K., & Elham, E. (2016). The priority of using hypertonic saline over ventolin in the treatment of bronchiolitis. Journal of Health Research and Reviews, 3(3), 98.
Price, D. B., Rigazio, A., Small, M. B., & Ferro, T. J. (2016). Historical cohort study examining comparative effectiveness of albuterol inhalers with and without integrated dose counter for patients with asthma or chronic obstructive pulmonary disease. Journal of asthma and allergy, 9, 145.