Viral Infection: Influenza Virus

This presentation provides an overview of the physiology, pathophysiology, pharmacology, and clinical practice for treating Influenza A virus. It covers topics such as the normal physiology of the virus, its pathophysiology, the use of antiviral medicines, and relevant clinical practices. The presentation aims to educate and inform about the nature of Influenza A and how it can be managed and treated.

Viral Infection: Influenza Virus

INTRODUCTION
 Influenza is a type of Flu or viral infection which is life threatening as it attacks, throat, lungs and nose.
 Patient suffering from viral infection experiences muscle ache and fever which weakens immune system of
body.
 The presentation is based on Influenza A which is highly contagious respiratory illness. The presentation
will outline physiology, pathophysiology, pharmacology and clinical practice to treat disease.

NORMAL PHYSIOLOGY
 Influenza A viruses are the most harmful ones and the reasons behind causing of a variety
of diseases. The host of the virus is wild aquatic birds.
 These viruses are transmitted from a bird to the human being and tends to cause devastating
outbreaks which are hard to recover.
 In human body, the infection attacks the human body by first impacting the respiratory
system and later the nose, throat and lungs. In some cases, its resolves on its own but
sometimes its complications become deadly for a human being.

PATHOPHYSIOLOGY
 Influenza A is an acute illness which targets upper respiratory tract can causes redness of trachea and upper respiratory
tree.
 The acute symptoms of illness continue for 10 days and the illness is self-limited to healthy individuals.
 The immune response to interferon response a flu is responsible for viral syndrome which comprise body aches, high
fever and coryza.
 The groups who are at high risk of flu are the individuals who have suffered or suffering from cardiac and chronic
lung diseases.
 The high-risk group of flu are pregnant woman who are prone to severe complications like secondary bacteria
pneumonia, primary viral pneumonia and hemorrhagic bronchitis. These complications increase within 48 hours from
symptoms and the impact of virus replicates in lower and upper respiratory passages which starts from time of
inoculation and peaks after 48 hours.

PHARMACOLOGY
 There are 3 antiviral medicines which are given in Australia to treat Virus Influenza A that is Tamiflu, Relenza and Symmetrel.
 Tamiflu which is Oseltamivir and Relenza which is Zanamivir are chemical drugs which are known as neuraminidase whereas
Symmetrel is a class of drug which is called as amantadine.
 The antiviral medicines are only available on prescription and helps in limits impact of Influenza if taken after onsets of 48
hours. Also, if the service user takes the medication within 48 hours of viral, it can reduce the risk of severity and duration of
illness.
 The common side effects of antivirals are sinusitis, runny or stuffy nose, nausea, cough, headache or throat infection.

CONTINUE
Oseltamivir
Mechanism of action
 The active metabolite is selective inhibitor and potent of influenza virus A neuraminidase enzymes which are normally
found in glycoproteins on virion surface.
 The activity of viral neuraminidase enzyme activity is relevant for entry of viral in uninfected cells which releases particles
of formed virus from infected cells and limits spread of flu.
Side effects
 The common side effects of Oseltamivir are vomiting and nausea which are experienced by patient during first two days of
action.

CONTINUE
Pharmacodynamics
 Oseltamivir is a prodrug which is administered by phosphate and when given to service user it hydrolyzes by esterase
which are located in live for active metabolite which is free carboxylate of medicine.
Pharmacokinetic
 These specified properties of drug that is low protein binding and independent metabolism of CYP450 and
glucuronidase system.
Routes of administration
 Oral: substance is taken through mouth and Intravenous: into the vein

RELEVANT CLINICAL PRACTICE
 Encouraging patient to intake adequate and balanced diet which is rich in
vitamin D, calcium and Phosphorus.
 Encouraging service user to involve in relaxing activities such as deep breathing.

CONCLUSION
 The presentation outline physiology, pathophysiology, Pharmacology and
clinical practice for treating influenza virus A.

REFERENCES
 Fielding, J. E., Regan, A. K., Dalton, C. B., Chilver, M. B., & Sullivan, S. G. (2016). How severe was the 2015
influenza season in Australia. Med J Aust. 204(2). 60-61.
 Mitchell, A. B., Mourad, B., Buddle, L., Peters, M. J., Oliver, B. G., & Morgan, L. C. (2018). Viruses in
bronchiectasis: a pilot study to explore the presence of community acquired respiratory viruses in stable patients
and during acute exacerbations. BMC pulmonary medicine. 18(1). 84.
 Marty, F. M., Vidal-Puigserver, J., Clark, C., Gupta, S. K., Merino, E., Garot, D., ... & Shortino, D. (2017).
Intravenous zanamivir or oral oseltamivir for hospitalised patients with influenza: an international, randomised,
double-blind, double-dummy, phase 3 trial. The Lancet Respiratory Medicine. 5(2). 135-146.