Physiology and Pharmacology of Pulmonary Arterial Hypertension

Pulmonary Arterial
hypertension

Physiology and homeostasis of
Pulmonary Arterial Hypertension
• Pulmonary arterial hypertension
occurs when the arteries narrow in
diameter throughout the lungs.
• It increases the resistance to the flow
of blood through the lungs. The
increase in pressure of blood
damages the heart (McGoon et al.,
2013).
• The changes in the pulmonary
arteries create problems for the heart
to pump blood which lead to an
increase in the blood pressure.
• Pulmonary arterial hypertension is
being caused by the development of
the scar tissue in the lung’s tiny blood
vessels.
• The scar tissue blocks the flow of
blood through the lungs and it
increases pressure on the blood
vessels.

Pathophysiology
• Obliteration in the pulmonary vascular wall and pathologic vasoconstriction is
mainly responsible for pulmonary vascular resistance.
• Pulmonary hypertension is caused by various factors like pathologic
vasoconstriction endothelial and smooth muscle proliferation, hypertrophy and
chronic inflammation.
• Vascular obstruction is also responsible for activating coagulation, which is
caused by an increase in pulmonary pressure and endothelium injuries.
• Pulmonary hypertension increases pulmonary venous pressure, which harms the
left side of the heart by increasing pressure in the left heart ventricle (Humbert,
2010).
• Pulmonary arteries also gain high pressure due to excessive stress which results
in causing injuries to the alveolar-capillary wall and edema.
• Pulmonary hypertension can be associated with gene mutation encoding bone
morphogenetic protein receptor type II, HIV infection and heart disease.
• In patients with high Pulmonary hypertension, high level of pro-inflammatory
cytokines like interleukin I, interleukin 6 and macrophage inflammatory protein
are found.
• Circulating autoantibodies are also found in the peripheral blood of the
Pulmonary hypertension patient.

Pharmacology
• Iloprost is being used for improving the flow of
blood who faces problems due to bad circulation.
• The drug works by widening the smaller blood
vessels and increases the flow of blood through
them (Heresi, 2010).
• It widens and relaxes the blood vessels in the lungs
and decreases the pulmonary pressure of blood in
order to improve its function.
• The decrease in the pressure of blood in the lungs
results in the ability to become more active.
• I-neb delivery system is a decision which is used for
administrating Iloprost.