The precise mechanism of action is uncertain, but the opioid is believed to bind to local opioid receptors in the lungs. This may modulate release of substance P and other tachykinins that affect the peripheral airways.
Opioids that have been used successfully:
(1) hydromorphone
(2) morphine sulfate (2 mg preservative-free in 5 mL sterile normal saline)
(3) fentanyl
It may be necessary to try several types of opioids to find one that works best for a particular patient.
The opioid is aerosolized in a nebulizer and then inhaled by the patient.
A patient may be suitable candidate for inhaled opioid if:
(1) the inhaled opioid provides relief
(2) the patient requires rapid relief
(3) the patient can be monitored for adverse effects
(4) any side effects are tolerable
(5) the patient is capable of breathing from a nebulizer
