Rocuronium (Zemuron)

Rocuronium (Zemuron)

Non-depolarizing intermediate acting paralytic

February 10, 2023

Dear Colleagues,

Welcome! In this edition of the UH EMS-I Pharmacy Phriday, the focus is the recent change within UH’s Rapid Sequence Intubation (RSI) protocol for adult patients and the use of Rocuronium. Rocuronium has replaced Succinylcholine as the preferred paralytic agent (Succinylcholine now becomes the backup medication if Rocuronium is unavailable). 

RSI is a two-part pharmacological process, including a sedative, or induction agent, followed by a paralytic.  (It is worth noting that the preferred sedative also changed with the new 2023 protocols and is now Ketamine). RSI should always follow basic airway management and maneuvers, including oxygenation. (See UH’s “Rapid Sequence Intubation (RSI)” protocol.) 


In RSI, two types of neuromuscular blocking agents (NMBA’s) can be used as a paralytic.  One is a depolarizing agent, and the other is a non-depolarizing agent.  The previous agent used under UH protocols was Succinylcholine, a depolarizing agent.  With a depolarizing agent, the neuromuscular block is created by depolarizing the membrane and not allowing for repolarization.  As the depolarization persists, the mechanism can cause a common side effect of the medication, fasciculations, or uncoordinated contractions of the muscle fibers. 

Rocuronium, now the first-line paralytic under UH protocols, is a non-depolarizing agent.  Rocuronium and other non-depolarizing agents are effective by competing with and blocking acetylcholine’s neurotransmitter action, preventing the muscle fibers from depolarizing (this mechanism eliminates the common side effect of fasciculations associated with Succinylcholine).  The effect quickly results in skeletal muscle paralysis to allow the intubation.  Non-depolarizing agents such as Rocuronium are known to cause muscle relaxation for longer periods than the depolarizing agent but typically have fewer contraindications and side effects. 

Like other NMBAs, a patient’s level of consciousness or perception of pain is not affected by Rocuronium.  A sedative must be used in the RSI procedure.  In fact, due to the longer lasting duration of Rocuronium (30-60 minutes), additional doses of a sedative may be needed. The paralysis will most likely outlast the sedation.  UH protocol recommends an additional dose of a sedative at 20 minutes or sooner. Watch for signs and symptoms of the sedative wearing off, such as tearing, wakefulness, facial grimacing, hypertension, or tachycardia, and have a lower threshold for additional sedation in these cases. 

Dosing for Rocuronium under the RSI protocol is 1 mg/kg IV/IO, with the usual dose being 100 mg.  The medication can be repeated if additional paralysis is needed.  For safety purposes, the medication and dosing must be verified by a second crew member.  And remember! Once the paralytic is administered, the airway must be managed! The only contraindication to Rocuronium is a sensitivity to the medication or other NMBAs. 

Rocuronium has been shown to have little effect on heart rate or blood pressure.   Literature indicates the possibility of hypo or hypertension in 1-2% of cases.  Literature also suggests that following Rocuronium administration, any patient who develops sudden cardiovascular collapse, especially with a rash, should be suspected of developing anaphylaxis. As mentioned above, an increase in heart rate or hypertension may suggest the need for additional sedation.

As a reminder, the use of Rocuronium and the UH RSI protocol is limited to departments and agencies approved by their medical director to do so.  Agencies interested in receiving permission to use the skill need to contact their medical director for approval and additional training. Agencies currently approved to perform RSI can expect new RSI boxes and in-service training if not having already received such.  Coordinate with your local medical director, EMS coordinator, or supplying pharmacy if there are questions.


Till next time, stay safe!!


The UH EMS-I Team

University Hospitals