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Nishika Patel
Critical care pharmacist with a fondness for cats, wine, and all things vintage. Also an insta-nerd who likes to teach ICU tidbits on her IG page @dr.scriptsndrips.
The Pre-brief
Epoprostenol (epo) (U.S. brand names: Flolan®, Veletri®) is a prostacyclin and potent vasodilator indicated for pulmonary arterial hypertension (WHO Group 1 PH). It is also used off-label for refractory acute respiratory distress syndrome (ARDS) and patients post CT surgery with complications of pulmonary hypertension, RV dysfunction, or refractory hypoxemia. Other medications in the prostacyclin class include iloprost, treprostinil, and selexipag.
Routes of administration:
Epo can be given in 2 ways – IV and inhaled (nebulized)
- The IV route leads to pulmonary vasodilation AND systemic vasodilation which causes hypotension. Furthermore, this route causes nonspecific vasodilation in the lungs which can redistribute pulmonary blood flow to poorly ventilated lung regions. This leads to worsening of VQ mismatch and hypoxemia.
- The benefit of the inhaled route is selective dilation of the pulmonary capillaries in alveoli which are well ventilated. This results in a reduction in pulmonary artery pressure and an improvement in oxygenation.
Dosing:
Check to see if your institution has an existing epo protocol in place as most institutions do.
Adverse effects:
Hypotension
- Epo is a potent vasodilator so IV administration will cause hypotension. Inhaled epo may result in minimal systemic absorption when compared to IV epo, but patients should still be monitored for hypotension.
Rebound pulmonary hypertension
- The half-life of epo is short (~6 minutes) so coordination with pharmacy is important to ensure therapy is not interrupted due to the risk of rebound pulmonary hypertension. Large sudden reductions in dosage can also cause rebound pulmonary hypertension so epo must be tapered slowly every 30 mins – 4 hrs to the lowest effective dose based on response and tolerability.
Bleeding
- Epo activates adenylate cyclase thereby increasing cAMP concentrations in platelets. This reduces platelet aggregation and can cause bleeding. While this is true for IV epo, there is insufficient evidence to suggest that inhaled epo increases bleeding. However, patients should still be monitored for this effect.
Pharmacy pearls:
- Flolan® (epo) should only be prepared with the glycine diluent provided.
- Veletri® (epo) can be prepared with NS or sterile water for injection.
- For inhaled epo with fixed dosing, preparation instructions should be followed carefully to ensure that a solution of the right concentration is produced.
The Debrief
- Utilize institution-specific epo dosing protocols to ensure consistent and safe care with this medication.
- Coordination with all specialties (intensivists, pharmacists, respiratory therapists, and nurses) is important to ensure treatment goals are understood and therapy is not interrupted prematurely.
- Taper epo slowly to avoid rebound pulmonary hypertension. Monitor patients for hypotension and bleeding.
- For inhaled epo with fixed dosing, the solution concentration should be halved each time tapering is indicated, but the nebulized rate should consistently remain at 8mL/hr.
References
- Epoprostenol. Lexi-Drugs. Lexicomp. Wolters Kluwer Health, Inc. Riverwoods, IL. Available at: http://online.lexi.com.
- Siobal M. Pulmonary Vasodilators. Respir Care. 2007; 52(7):885– 899.
