Which of the following muscle relaxant has the maximum duration of action
**Core Concept**
Non-depolarizing muscle relaxants (NDMRs) are a class of medications used to induce muscle relaxation during surgical procedures. They work by competing with acetylcholine for receptor sites at the neuromuscular junction, thereby inhibiting the transmission of nerve impulses to muscles.
**Why the Correct Answer is Right**
The correct answer is Rocuronium, which has a rapid onset and intermediate duration of action, typically lasting around 45-60 minutes. This duration is due to its rapid hydrolysis by plasma cholinesterase, resulting in a quick recovery of neuromuscular function. Rocuronium's efficacy and pharmacokinetics make it a popular choice for anesthesia.
**Why Each Wrong Option is Incorrect**
**Option A:** Vecuronium has a relatively short duration of action, typically lasting around 30-40 minutes, making it less suitable for long procedures.
**Option B:** Cisatracurium has a moderate duration of action, typically lasting around 60-90 minutes, but its onset is slower compared to rocuronium.
**Option C:** Pancuronium has a long duration of action, typically lasting around 60-120 minutes, but its onset is slower and it has a higher incidence of cardiovascular side effects.
**Clinical Pearl / High-Yield Fact**
It's essential to note that the duration of action of muscle relaxants can be affected by various factors, including patient age, renal function, and concurrent use of other medications. Always consider these factors when selecting a muscle relaxant for a patient.
**Correct Answer:** C. Pancuronium, 60-120 minutes.