Core pharmacology

Class Group

PULMONARY VASODILATORS

Legacy Cicm Level

Level 3

Introduction

Epoprostenol (Inhaled or continuous infusion)
Iloprost (inhaled)

PGI2 is a the main arachidonic acid metabolite in vascular endothelium

Indications Uses

1. Pulmonary hypertension
2. Refractory hypoxia
3. Anticoagulation including CRRT and limb ischaemia
4. Pre-eclampsia

Chemical Pharmaceutics

Epoprostenol:
PGI2 is reconstituted in a highly viscous and basic glycine diluent (causes tracheitis)

Presentation

Can be delivered as a continuous IV infusion or continuous nebulizer

Main Action

pulmonary vasodilation

Mechanism of action

Agonist at IP receptor
- GsPCR receptor
- → Increased cAMP via adenylyl cyclase
- → Smooth muscle relaxation and inhibits smooth muscle growth

Physiological effects

- Pulmonary vasodilation by agents given via inhalational route → vasodilation of
ventilated blood vessels → increased perfusion → improved V/Q matching
- Improved V/Q matching → increased paO2
- Pulmonary vasodilation → decreased PVR → Decreased RVSP and improves RV
funcion

Adverse Effects Toxicity

Flushing
Headache
Nausea
Hypotension
Diarrhoea

Absorption

Highly lipid soluble and rapidly absorbed through alveoli

Distribution

Little Systemic distribution after inhalation

Metabolism

Rapidly removed from circulation by hydrolysis to 6-oxo-PGF1 alpha in blood

Half-life

Plasma half life is 30sec-3min

Special Points

Benefits of inhalational route
- Reduced systemic effects
Delivery of drug to ventilated areas → selective vasodilation → improved V/Q

Route And Dose

Inh