Muscle Rigidity after Rapid Fentanyl Administration

From Susan's patient case presentation:

Fentanyl, 50-100 x's more potent than morphine, may produce muscle rigidity in particular chest wall rigidity. High doses and/or too rapid administration have been implicated as causal factors. This has also been seen with morphine.

Reversal with naloxone has shown to be effective....but use caution with cardiac patients b/c naloxone can cause changes in cardiovascular hemodynamics. Also, giving too much naloxone or giving it too fast can cause pulmonary edema.

Usual rate of administration of fentanyl IV push is over 5 minutes, diluted 1:1 with normal saline.