Understanding What is Another Name for Pancuronium
For many drugs, multiple names can be used, including a generic name, a brand name, and a chemical name. Pancuronium is no exception. While its generic name is simply pancuronium, a more specific form is pancuronium bromide, which is a sterile, isotonic solution. However, the most widely recognized name for this medication in clinical settings is its brand name.
The Brand Name: Pavulon
The most common brand name for pancuronium is Pavulon. This is the name under which it was originally marketed and is still frequently used by clinicians, especially when discussing its historical use. While the brand name is well-known, generic forms of pancuronium bromide are also available from various manufacturers. For healthcare professionals, recognizing both the generic and brand names is crucial for patient safety and accurate communication.
The Pharmacology of Pancuronium
Pancuronium is classified as a non-depolarizing neuromuscular blocking drug (NMBD) and is part of the aminosteroid group. Unlike depolarizing agents like succinylcholine, it does not cause muscle fasciculations (twitching) upon administration. Its mechanism is based on competitive inhibition.
Mechanism of Action
At the neuromuscular junction, pancuronium acts as a competitive antagonist to the nicotinic acetylcholine receptors. It blocks the binding of acetylcholine (ACh), the neurotransmitter responsible for triggering muscle contraction. By occupying these receptors, it prevents ACh from causing depolarization and muscle activation, leading to muscle paralysis. Its poor lipid solubility means it does not cross the blood-brain barrier, so it has no effect on consciousness or pain perception. This is a critical point, as patients must also receive adequate sedation or anesthesia during its use to prevent serious psychic trauma.
Clinical Applications
Pancuronium is used as an adjunct to general anesthesia for several purposes in a hospital or clinic setting:
- Facilitating endotracheal intubation: It provides the necessary muscle relaxation of the larynx to allow for the safe and efficient placement of a breathing tube.
- Providing skeletal muscle relaxation during surgery: Its long duration of action makes it suitable for surgical procedures requiring extensive periods of muscle immobility.
- Assisting with mechanical ventilation: In intensive care units, pancuronium can be used to manage patients who are resisting mechanical ventilation, though this is less common today.
- Treating conditions with severe muscle spasms: In rare cases, it can be used for severe tetanus or status epilepticus to help control muscle activity and ensure adequate ventilation.
Administration and Monitoring
Pancuronium is for intravenous use only and should be administered by or under the supervision of experienced clinicians. Dosage is carefully individualized based on patient weight and the desired duration of action. To ensure effective muscle blockade and avoid overdosage, neuromuscular function is monitored using a peripheral nerve stimulator.
Monitoring neuromuscular blockade
Clinicians use several methods to monitor the degree of paralysis:
- Train-of-four (TOF) stimulation: Four electrical impulses are delivered to a peripheral nerve (e.g., ulnar nerve), and the resulting muscle twitches are measured. The ratio of the fourth twitch to the first helps quantify the degree of blockade.
- Tetanic stimulation: A continuous, high-frequency stimulation is applied. The fade in the muscular response indicates a nondepolarizing block.
Reversal of neuromuscular blockade
To reverse the effects of pancuronium at the end of a procedure, anticholinesterase agents are used. These agents, such as neostigmine, edrophonium, or pyridostigmine, increase the availability of acetylcholine, which outcompetes pancuronium for the receptors at the neuromuscular junction. Adequate ventilatory support must be maintained until the patient can breathe independently.
Comparison with Other Neuromuscular Blockers
While pancuronium was historically very important, its use has declined in favor of intermediate-acting NMBAs that offer more flexibility in duration. The table below compares pancuronium to other common agents.
| Feature | Pancuronium | Vecuronium | Rocuronium |
|---|---|---|---|
| Onset | Relatively slow (3-5 min) | Intermediate | Rapid (1-2 min) |
| Duration | Long (60-90 min) | Intermediate | Intermediate |
| Reversal | Slower reversal than intermediate agents | Faster reversal than pancuronium | Rapid reversal with sugammadex |
| Primary Clearance | Renal (80%) | Hepatic | Hepatic |
| Cardiovascular Effects | Moderate tachycardia, hypertension | Minimal changes | Minimal changes |
| Histamine Release | No significant histamine release | No significant histamine release | Minimal histamine release |
Risks and Side Effects
As with any potent medication, pancuronium carries risks and side effects. Because it blocks the actions of the vagus nerve (vagolytic effect), it can lead to cardiovascular changes, such as tachycardia (increased heart rate) and hypertension (high blood pressure). Other potential side effects include excessive salivation, rash, and bronchospasm.
In patients with pre-existing renal or hepatic disease, caution is needed due to pancuronium's primary renal clearance and potential for active metabolite accumulation. Prolonged paralysis and muscle weakness have been reported after long-term use in intensive care settings. It is also essential to remember that since pancuronium has no effect on consciousness, it must be used with adequate sedation to prevent the patient from experiencing paralysis while awake.
Conclusion
In summary, while the generic name is pancuronium, its most well-known alternative name is the brand name, Pavulon. As a long-acting, non-depolarizing neuromuscular blocker, pancuronium functions by competitively inhibiting acetylcholine at the neuromuscular junction. It has proven valuable in surgical and critical care settings for achieving skeletal muscle relaxation but requires careful monitoring and is associated with specific side effects, particularly cardiovascular effects. Due to its prolonged duration and reliance on renal clearance, newer intermediate-acting agents are often preferred today, but pancuronium remains a significant medication in pharmacology. For comprehensive prescribing information, refer to official drug information sources, such as the prescribing information available on RxList.
