Pancuronium bromide, also known by the brand name Pavulon, is a neuromuscular blocking agent (NMBA) used in medicine, primarily in anesthesiology and critical care. It is a powerful medication administered intravenously and requires careful administration by experienced clinicians due to its effects.
The Mechanism of Action
Pancuronium functions as a nondepolarizing neuromuscular blocking agent. It acts as a competitive antagonist to acetylcholine (ACh) at the neuromuscular junction. Acetylcholine is a neurotransmitter responsible for triggering muscle contraction. By binding to the same receptors on the muscle cell, pancuronium prevents acetylcholine from initiating a contraction, leading to muscle weakness and paralysis in a dose-dependent manner. {Link: Drugs.com https://www.drugs.com/pro/pancuronium.html}, {Link: DrugBank https://go.drugbank.com/drugs/DB01337}, {Link: Pfizer https://labeling.pfizer.com/ShowLabeling.aspx?id=4562}
Primary Uses of Pancuronium in Medicine
Pancuronium is used for specific medical procedures and its long duration of action requires careful monitoring.
Use during Anesthesia and Surgery
Pancuronium is commonly used as an adjunct to general anesthesia for tracheal intubation and providing skeletal muscle relaxation. {Link: Drugs.com https://www.drugs.com/pro/pancuronium.html}, {Link: DrugBank https://go.drugbank.com/drugs/DB01337}, {Link: Pfizer https://labeling.pfizer.com/ShowLabeling.aspx?id=4562}
Use in Critical Care
In intensive care units, pancuronium is sometimes used for patients requiring long-term mechanical ventilation. This may be necessary in situations such as patient-ventilator asynchrony or the management of severe spasms. {Link: Drugs.com https://www.drugs.com/pro/pancuronium.html}, {Link: DrugBank https://go.drugbank.com/drugs/DB01337}, {Link: Pfizer https://labeling.pfizer.com/ShowLabeling.aspx?id=4562}
Administration and Reversal
Pancuronium is given intravenously and the dosage is determined based on factors like the patient's weight, the type of anesthetic used, and the purpose of administration. Neuromuscular blockade is monitored using a peripheral nerve stimulator. The effects of pancuronium can be reversed with anticholinesterase agents like neostigmine.
Side Effects and Considerations
Common side effects of pancuronium include cardiovascular effects such as tachycardia and increased blood pressure, primarily due to its vagolytic properties. Prolonged paralysis or muscle weakness can occur, especially with long-term use in the ICU or in patients with kidney or liver problems. Allergic reactions are rare but possible. Pancuronium's effects can be influenced by various other medications and electrolyte imbalances.
Pancuronium vs. Rocuronium: A Comparison
While pancuronium was historically a frequently used NMBA, intermediate-acting agents like rocuronium are now often preferred due to their faster onset and shorter duration.
| Feature | Pancuronium | Rocuronium |
|---|---|---|
| Onset of Action | Slow (3-5 minutes) | Fast (60 seconds for intubation) |
| Duration of Action | Long (60-90 minutes or longer) | Intermediate (around 45 minutes) |
| Elimination | Primarily renal | Primarily hepatic/biliary |
| Cardiovascular Effects | Weak vagolytic effect causing mild tachycardia | Less significant hemodynamic effects |
| Reversibility | Reversible with neostigmine | Reversible with neostigmine or sugammadex |
Conclusion
Pancuronium is a long-acting, nondepolarizing neuromuscular blocking agent used to induce muscle relaxation for surgical procedures and to facilitate mechanical ventilation in critically ill patients. Its administration requires expert medical supervision and full respiratory support. Although intermediate-acting NMBAs are often used instead for routine purposes due to pancuronium's prolonged effect and renal elimination, pancuronium remains a cost-effective and useful option in specific situations where a longer duration of paralysis is needed. Careful patient evaluation and monitoring are crucial for its safe use.
Frequently Asked Questions
Q: What is pancuronium used for in surgery? A: Pancuronium is used during surgery as an adjunct to general anesthesia for skeletal muscle relaxation and tracheal intubation.
Q: How does pancuronium affect a patient on a ventilator? A: For patients on mechanical ventilation, pancuronium is used to relax respiratory muscles, aiding in ventilation, especially for those resisting the ventilator.
Q: How is pancuronium's effect reversed? A: The effects can be reversed using anticholinesterase agents like neostigmine.
Q: Is pancuronium safe for long-term use? A: Long-term use is generally avoided due to the risk of prolonged paralysis and muscle weakness, particularly with kidney issues.
Q: What are the main side effects of pancuronium? A: Main side effects include increased heart rate and blood pressure.
Q: Who cannot use pancuronium? A: It is contraindicated in patients with hypersensitivity to the drug or bromides; use caution with kidney or liver issues, heart disease, or myasthenia gravis.
Q: Does pancuronium relieve pain? A: No, it is a muscle relaxant and requires concurrent anesthesia or sedation. {Link: Drugs.com https://www.drugs.com/pro/pancuronium.html}, {Link: DrugBank https://go.drugbank.com/drugs/DB01337}, {Link: Pfizer https://labeling.pfizer.com/ShowLabeling.aspx?id=4562}
