Table of ContentsView AllTable of ContentsUsesHow They WorkExamplesLimitationsSide EffectsSummary
Table of ContentsView All
View All
Table of Contents
Uses
How They Work
Examples
Limitations
Side Effects
Summary
Paralytic drugs, or neuromuscular blocking agents (NMBAs), are powerful muscle relaxants used to prevent muscle movement during surgical procedures. They’re also used during critical care, such as when a person is intubated and placed on a ventilator due to severe respiratory illness.
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Why and When Paralytics Are Used
Paralyzing drugs are commonly used during:
Surgery
Paralytics are used as part ofgeneral anesthesiato prevent movement during surgery. General anesthesia involves medications that put you to sleep and prevent pain, like ketamine, as well as muscle paralytics to prevent movement.
Because surgery uses sharp instruments and affects delicate areas of the body, even involuntary movements, such as a sneeze or a small muscle twitch, could cause a serious injury. For this reason, muscle movement has to be medically suppressed during surgery, with the exception of the muscle movement that’s necessary for breathing.
Critical Care
Sometimes, neuromuscular blocking agents are used during intensive care for severe respiratory distress syndrome when a person requiresintubation(insertion of a breathing tube in the throat) due to impaired breathing.
However, paralytics aren’t always used for intubation, especially if a patient is being treated outside of a medical facility in an emergency, when these drugs may not be readily available.
Paralytic drugs are also given to stop shivering due to therapeutichypothermia, a type of treatment used to temporarily lower body temperature in certain situations, such ascardiac arrest. This can help reduce brain damage and long-term problems.
When neuromuscular blocking agents are used during critical care, they are usually used for a longer time period than when they are used during surgery. In these situations, muscle paralysis is usually maintained for 12 to 24 hours or longer.
How Paralytic Drugs Work
Paralytic drugs temporarily interfere with the messages that nerves send to the skeletal muscles of the body. The skeletal muscles are those that control movements of the face, arms, legs, back, and trunk.
Paralytic drugs are rapidly distributed throughout the body after they are injected. They quickly bind to and block neuromuscular binding sites on muscles to prevent them from functioning.
Generally, paralytic drugs are administered for the duration of surgery, which can last for less than half an hour or up to several hours, depending on the procedure. If you are having a paralytic drug during critical care for a respiratory condition, you may have it for a longer period of time, such as 12 to 24 hours or longer.
These drugs can affect people differently. For example, they may take longer to work in adults over age 80, or their action can last longer for people who have kidney or liver disease.
Commonly Used Paralytic Drugs
Paralytic drugs are available in hospitals and surgical facilities. Your dose would be carefully selected before it is started, and you need to be closely monitored if you receive any of these medications.
Succinylcholine, a rapid-onset, short-acting depolarizing muscle relaxant, has traditionally been the drug of choice when rapid muscle relaxation is needed. Some patients wonder if propofol is a paralytic drug. It is not; it is a sedative. It is used to put you to sleep during a medical procedure.
Common paralytics used for surgery include:
When surgery is complete, medication is given to reverse the effects of the paralytic drugs. Examples include acetylcholinesterase inhibitors, neostigmine, pyridostigmine, and edrophonium. As with paralytic drugs, the dosage must be carefully selected to avoid negative side effects.
What Paralytics Don’t Do
General anesthesia involves a combination of medications, monitoring, and support. Paralytics are one part of the whole general anesthesia process, and they do not impact pain or memory. Other anesthetic medications provide sedation (put you to sleep) and pain control.
Sedation that’s given for surgery also prevents people from remembering the surgery, as well as aspects of the immediate pre-operative and post-operative period.
Local Anesthesia
Neuromuscular blocking agents are different fromlocal anestheticsthat are injected to prevent pain in a small region of your body. Local anesthetics used for surgery might be injected while you are awake—such as during dermatologic procedures, some types of limb surgeries, and more.
Home Use
Neuromuscular blocking agents are not used at home. Some milder muscle relaxants, like Flexeril (cyclobenzaprine) or Ryanodex (dantrolene), are taken orally or injected for problems like muscle spasms or pain, but they are not as powerful as neuromuscular blocking agents that are used for surgery.
Normally, it can take several minutes to an hour to be able to move again after paralytic drugs are stopped or reversed because these are short-acting medications. You will be monitored as you recover from all of the medications administered for your general anesthesia—including sedation and pain control medications.
Even with appropriate use and careful monitoring, common side effects of neuromuscular blocking agents can cause side effects.
Common Side Effects
Some common side effects of neuromuscular blocking agents include:
During surgery, you would be monitored so that your anesthesiologist would be able to detect these side effects quickly. Treatment would be initiated right away so that your surgery can proceed safely.
Severe Side Effects
Serious side effects of neuromuscular blocking agents can include:
Severe complications are more common among people who are at high risk due to heart disease, lung disease, obesity, or neuromuscular disease.Part of yourpre-surgical testinginvolves identifying potential predisposing factors that could put you at an increased risk of anesthesia side effects and potentially adjusting your anesthesia dosing in advance to avoid adverse effects.
After surgery, your healthcare providers will monitor you in the recovery area to determine whether you are having any side effects as the medication wears off. If you develop any side effects, treatment would be initiated right away. This can include interventions such as oxygen or medication for your heart or lungs.
Paralytic drugs are commonly used to keep the body immobile during surgery. These medications are used alongside general anesthesia, which prevents pain and keeps you asleep during the procedure.
Paralytic drugs, also called neuromuscular blocking agents, can also be used in certain critical care procedures, such as during the insertion of a breathing tube.
Paralytic drugs are short-acting medications, so their effects wear off quickly after surgery. If you have concerns about the use of these medications during a procedure, discuss them with your healthcare provider. Your provider can give you more information about the specific medication being used, potential side effects, and possible alternatives.
13 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Adeyinka A, Layer DA.Neuromuscular blocking agents. In:StatPearls. StatPearls Publishing; 2024.Elsevier. Drug Class Overview.Neuromuscular Blocking Agents.Hadique S, Badami V, Forte M.The implementation of protocol-based utilization of neuromuscular blocking agent using clinical variables in acute respiratory distress syndrome patients.Crit Care Explor. 2021;3(3):e0371. doi:10.1097/CCE.0000000000000371Roantree RAG, Furtado CS, Goldstein S.EMS Facilitated Intubation Without Paralytics. [Updated 2022 Oct 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-.Renew JR, Ratzlaff R, Hernandez-Torres V, Brull SJ, Prielipp RC.Neuromuscular blockade management in the critically Ill patient.J Intensive Care. 2020;8(1):37. doi:10.1186/s40560-020-00455-2Tezcan B, Turan S, Özgök A.Current use of neuromuscular blocking agents in intensive care units.Turk J Anaesthesiol Reanim. 2019;47(4):273-281. doi:10.5152/TJAR.2019.33269Boon M, Martini C, Dahan A.Recent advances in neuromuscular block during anesthesia.F1000Res. 2018;7:167. doi:10.12688/f1000research.13169.1Bjerring C, Vested M, Arleth T, Eriksen K, Albrechtsen C, Rasmussen LS.Onset time and duration of action of rocuronium 0.6 mg/kg in patients above 80 years of age: A comparison with young adults.Acta Anaesthesiol Scand.2020;64(8):1082-1088. doi:10.1111/aas.13645Althoff FC, Xu X, Wachtendorf LJ, Shay D, Patrocinio M, Schaefer MS, Houle TT, Fassbender P, Eikermann M, Wongtangman K.Provider variability in the intraoperative use of neuromuscular blocking agents: a retrospective multicentre cohort study.BMJ Open. 2021;11(4):e048509. doi:10.1136/bmjopen-2020-048509Shay D, Wongtangman K, Eikermann M, Schaefer MS.The effects of acetylcholinesterase inhibitors on morbidity after general anesthesia and surgery.Neuropharmacology. 2020;173:108134. doi:10.1016/j.neuropharm.2020.108134Peck J, Urits I, Crane J, McNally A, Noor N, Patel M, Berger AA, Cornett EM, Kassem H, Kaye AD, Viswanath O.Oral Muscle Relaxants for the Treatment of Chronic Pain Associated with Cerebral Palsy.Psychopharmacol Bull. 2020 Oct 15;50(4 Suppl 1):142-162.DeFalco AP, Buol C.Neuromuscular blocking agents and skeletal muscle relaxants. In:Side Effects of Drugs Annual. Vol 44. Elsevier; 2022:199-211. doi:10.1016/bs.seda.2022.08.004Niu L, Wang Y, Yao C, Sun Y, Yao S, Lin Y.Efficacy and safety of neuromuscular blockade in overweight patients undergoing nasopharyngeal surgery.Med Sci Monit.2020;26:e926452. doi:10.12659/MSM.926452
13 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Adeyinka A, Layer DA.Neuromuscular blocking agents. In:StatPearls. StatPearls Publishing; 2024.Elsevier. Drug Class Overview.Neuromuscular Blocking Agents.Hadique S, Badami V, Forte M.The implementation of protocol-based utilization of neuromuscular blocking agent using clinical variables in acute respiratory distress syndrome patients.Crit Care Explor. 2021;3(3):e0371. doi:10.1097/CCE.0000000000000371Roantree RAG, Furtado CS, Goldstein S.EMS Facilitated Intubation Without Paralytics. [Updated 2022 Oct 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-.Renew JR, Ratzlaff R, Hernandez-Torres V, Brull SJ, Prielipp RC.Neuromuscular blockade management in the critically Ill patient.J Intensive Care. 2020;8(1):37. doi:10.1186/s40560-020-00455-2Tezcan B, Turan S, Özgök A.Current use of neuromuscular blocking agents in intensive care units.Turk J Anaesthesiol Reanim. 2019;47(4):273-281. doi:10.5152/TJAR.2019.33269Boon M, Martini C, Dahan A.Recent advances in neuromuscular block during anesthesia.F1000Res. 2018;7:167. doi:10.12688/f1000research.13169.1Bjerring C, Vested M, Arleth T, Eriksen K, Albrechtsen C, Rasmussen LS.Onset time and duration of action of rocuronium 0.6 mg/kg in patients above 80 years of age: A comparison with young adults.Acta Anaesthesiol Scand.2020;64(8):1082-1088. doi:10.1111/aas.13645Althoff FC, Xu X, Wachtendorf LJ, Shay D, Patrocinio M, Schaefer MS, Houle TT, Fassbender P, Eikermann M, Wongtangman K.Provider variability in the intraoperative use of neuromuscular blocking agents: a retrospective multicentre cohort study.BMJ Open. 2021;11(4):e048509. doi:10.1136/bmjopen-2020-048509Shay D, Wongtangman K, Eikermann M, Schaefer MS.The effects of acetylcholinesterase inhibitors on morbidity after general anesthesia and surgery.Neuropharmacology. 2020;173:108134. doi:10.1016/j.neuropharm.2020.108134Peck J, Urits I, Crane J, McNally A, Noor N, Patel M, Berger AA, Cornett EM, Kassem H, Kaye AD, Viswanath O.Oral Muscle Relaxants for the Treatment of Chronic Pain Associated with Cerebral Palsy.Psychopharmacol Bull. 2020 Oct 15;50(4 Suppl 1):142-162.DeFalco AP, Buol C.Neuromuscular blocking agents and skeletal muscle relaxants. In:Side Effects of Drugs Annual. Vol 44. Elsevier; 2022:199-211. doi:10.1016/bs.seda.2022.08.004Niu L, Wang Y, Yao C, Sun Y, Yao S, Lin Y.Efficacy and safety of neuromuscular blockade in overweight patients undergoing nasopharyngeal surgery.Med Sci Monit.2020;26:e926452. doi:10.12659/MSM.926452
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Adeyinka A, Layer DA.Neuromuscular blocking agents. In:StatPearls. StatPearls Publishing; 2024.Elsevier. Drug Class Overview.Neuromuscular Blocking Agents.Hadique S, Badami V, Forte M.The implementation of protocol-based utilization of neuromuscular blocking agent using clinical variables in acute respiratory distress syndrome patients.Crit Care Explor. 2021;3(3):e0371. doi:10.1097/CCE.0000000000000371Roantree RAG, Furtado CS, Goldstein S.EMS Facilitated Intubation Without Paralytics. [Updated 2022 Oct 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-.Renew JR, Ratzlaff R, Hernandez-Torres V, Brull SJ, Prielipp RC.Neuromuscular blockade management in the critically Ill patient.J Intensive Care. 2020;8(1):37. doi:10.1186/s40560-020-00455-2Tezcan B, Turan S, Özgök A.Current use of neuromuscular blocking agents in intensive care units.Turk J Anaesthesiol Reanim. 2019;47(4):273-281. doi:10.5152/TJAR.2019.33269Boon M, Martini C, Dahan A.Recent advances in neuromuscular block during anesthesia.F1000Res. 2018;7:167. doi:10.12688/f1000research.13169.1Bjerring C, Vested M, Arleth T, Eriksen K, Albrechtsen C, Rasmussen LS.Onset time and duration of action of rocuronium 0.6 mg/kg in patients above 80 years of age: A comparison with young adults.Acta Anaesthesiol Scand.2020;64(8):1082-1088. doi:10.1111/aas.13645Althoff FC, Xu X, Wachtendorf LJ, Shay D, Patrocinio M, Schaefer MS, Houle TT, Fassbender P, Eikermann M, Wongtangman K.Provider variability in the intraoperative use of neuromuscular blocking agents: a retrospective multicentre cohort study.BMJ Open. 2021;11(4):e048509. doi:10.1136/bmjopen-2020-048509Shay D, Wongtangman K, Eikermann M, Schaefer MS.The effects of acetylcholinesterase inhibitors on morbidity after general anesthesia and surgery.Neuropharmacology. 2020;173:108134. doi:10.1016/j.neuropharm.2020.108134Peck J, Urits I, Crane J, McNally A, Noor N, Patel M, Berger AA, Cornett EM, Kassem H, Kaye AD, Viswanath O.Oral Muscle Relaxants for the Treatment of Chronic Pain Associated with Cerebral Palsy.Psychopharmacol Bull. 2020 Oct 15;50(4 Suppl 1):142-162.DeFalco AP, Buol C.Neuromuscular blocking agents and skeletal muscle relaxants. In:Side Effects of Drugs Annual. Vol 44. Elsevier; 2022:199-211. doi:10.1016/bs.seda.2022.08.004Niu L, Wang Y, Yao C, Sun Y, Yao S, Lin Y.Efficacy and safety of neuromuscular blockade in overweight patients undergoing nasopharyngeal surgery.Med Sci Monit.2020;26:e926452. doi:10.12659/MSM.926452
Adeyinka A, Layer DA.Neuromuscular blocking agents. In:StatPearls. StatPearls Publishing; 2024.
Elsevier. Drug Class Overview.Neuromuscular Blocking Agents.
Hadique S, Badami V, Forte M.The implementation of protocol-based utilization of neuromuscular blocking agent using clinical variables in acute respiratory distress syndrome patients.Crit Care Explor. 2021;3(3):e0371. doi:10.1097/CCE.0000000000000371
Roantree RAG, Furtado CS, Goldstein S.EMS Facilitated Intubation Without Paralytics. [Updated 2022 Oct 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-.
Renew JR, Ratzlaff R, Hernandez-Torres V, Brull SJ, Prielipp RC.Neuromuscular blockade management in the critically Ill patient.J Intensive Care. 2020;8(1):37. doi:10.1186/s40560-020-00455-2
Tezcan B, Turan S, Özgök A.Current use of neuromuscular blocking agents in intensive care units.Turk J Anaesthesiol Reanim. 2019;47(4):273-281. doi:10.5152/TJAR.2019.33269
Boon M, Martini C, Dahan A.Recent advances in neuromuscular block during anesthesia.F1000Res. 2018;7:167. doi:10.12688/f1000research.13169.1
Bjerring C, Vested M, Arleth T, Eriksen K, Albrechtsen C, Rasmussen LS.Onset time and duration of action of rocuronium 0.6 mg/kg in patients above 80 years of age: A comparison with young adults.Acta Anaesthesiol Scand.2020;64(8):1082-1088. doi:10.1111/aas.13645
Althoff FC, Xu X, Wachtendorf LJ, Shay D, Patrocinio M, Schaefer MS, Houle TT, Fassbender P, Eikermann M, Wongtangman K.Provider variability in the intraoperative use of neuromuscular blocking agents: a retrospective multicentre cohort study.BMJ Open. 2021;11(4):e048509. doi:10.1136/bmjopen-2020-048509
Shay D, Wongtangman K, Eikermann M, Schaefer MS.The effects of acetylcholinesterase inhibitors on morbidity after general anesthesia and surgery.Neuropharmacology. 2020;173:108134. doi:10.1016/j.neuropharm.2020.108134
Peck J, Urits I, Crane J, McNally A, Noor N, Patel M, Berger AA, Cornett EM, Kassem H, Kaye AD, Viswanath O.Oral Muscle Relaxants for the Treatment of Chronic Pain Associated with Cerebral Palsy.Psychopharmacol Bull. 2020 Oct 15;50(4 Suppl 1):142-162.
DeFalco AP, Buol C.Neuromuscular blocking agents and skeletal muscle relaxants. In:Side Effects of Drugs Annual. Vol 44. Elsevier; 2022:199-211. doi:10.1016/bs.seda.2022.08.004
Niu L, Wang Y, Yao C, Sun Y, Yao S, Lin Y.Efficacy and safety of neuromuscular blockade in overweight patients undergoing nasopharyngeal surgery.Med Sci Monit.2020;26:e926452. doi:10.12659/MSM.926452
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