Describe the mechanism of action, and adverse effects, of pulmonary vasodilators that are administered via the inhalational route.

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College Answer

Many candidates neglected to include oxygen which is also a drug with significant
pulmonary vasodilating properties. Accurate detail concerning the receptor and
second messenger effects of drugs was expected. The importance of V/Q matching
and reduction in systemic effects via inhalational administration needed to be stated.
Better answers included discussion of serious adverse effects such as methaemoglobinaemia,
acute lung injury, systemic hypotension, rebound phenomena
and heart failure.
Syllabus: B2a, 2b,c,d,e
Recommended sources: Basic and Clinical Pharmacology, Katzung, Chp 18, 19