|Trade names||Norcuron, others|
|Onset of action||< 1 min|
|Elimination half-life||51–80 minutes (longer with renal failure)|
|Duration of action||15 - 30 min|
|Excretion||Fecal (40–75%) and kidney (30% as unchanged drug and metabolites)|
|CompTox Dashboard (EPA)|
|Chemical and physical data|
|Molar mass||637.73 g/mol g·mol−1|
|3D model (JSmol)|
|(what is this?)|
Vecuronium bromide, sold under the brand name Norcuron among others, is a medication used as part of general anesthesia to provide skeletal muscle relaxation during surgery or mechanical ventilation. It is also used to help with endotracheal intubation; however, suxamethonium (succinylcholine) is generally preferred if this needs to be done quickly. It is given by injection into a vein. Effects are greatest at about 4 minutes and last for up to an hour.
Side effects may include low blood pressure and prolonged paralysis. Allergic reactions are rare. It is unclear if use in pregnancy is safe for the baby. Vecuronium is in the aminosteroid neuromuscular-blocker family of medications and is of the non-depolarizing type. It works by blocking the action of acetylcholine on skeletal muscles.
Vecuronium was approved for medical use in the United States in 1984. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Vecuronium is available as a generic medication. In the United States it is less than US$25 a dose. The effects may be reversed with a combination of neostigmine and atropine.
Vecuronium operates by competing for the cholinoceptors at the motor end plate, thereby exerting its muscle-relaxing properties, which are used adjunctively to general anesthesia. Under balanced anesthesia, the time to recovery to 25% of control (clinical duration) is approximately 25 to 40 minutes after injection and recovery is usually 95% complete approximately 45 to 65 minutes after injection of an intubating dose. The neuromuscular blocking action of vecuronium is slightly enhanced in the presence of potent inhalation anesthetics. If vecuronium is first administered more than 5 minutes after the start of the inhalation of enflurane, isoflurane, or halothane, or when a steady state has been achieved, the intubating dose of vecuronium may be decreased by approximately 15%.
Vecuronium has an active metabolite, 3-desacetyl-vecuronium, that has 80% of the effect of vecuronium. Accumulation of this metabolite which is cleared by the kidneys can prolong the duration of action of the drug, particularly when an infusion is used in a person with renal failure.
As long ago as 1862, adventurer Don Ramon Paez described a Venezuelan poison, guachamaca, which the indigenous peoples used to lace sardines as bait for herons and cranes. If the head and neck of a bird so killed was cut off, the remainder of the flesh could be eaten safely. Paez also described the attempt of a Llanero woman to murder a rival to her lover's affections with guachamaca and unintentionally killed 10 other people when her husband shared his food with their guests. It is probable that the plant was Malouetia nitida or Malouetia schomburgki.
The genus Malouetia (Family Apocynaceae) is found in both South America and Africa. The botanist Robert E. Woodson Jr comprehensively classified the American species of Malouetia in 1935. At that time, only one African species of Malouetia was recognised, but the following year Woodson described a second: Malouetia bequaertiana, from the Belgian Congo.
It was in 1960 that scientists reported the isolation of malouetine from the roots and bark of Malouetia bequaertiana Woodson by means of an ion exchange technique. A pure form of the substance was first synthesised in 1964, and was named pancuronium bromide. The name was derived from p(iperidino)an(drostane)cur(arising)-onium.
A paper published in 1973 discussed the structure-activity relationships of a series of aminosteroid muscle relaxants, including the mono-quaternary analogue of pancuronium, later called vecuronium.
It is commercially available as ampoules containing 4 or 10 mg of the drug in powder form which needs to be dissolved in distilled water prior to being given.
Vecuronium bromide has been used as part of a drug cocktail that prisons in the United States use as a means to put a condemned prisoner to death. Vecuronium is used to paralyze the prisoner and stop his or her breathing, in conjunction with a sedative and potassium chloride to stop the prisoner's heart. Injections of vecuronium bromide without proper sedation allow the person to be fully awake but unable to move in response to pain.
A dreadful case of poisoning by means of this plant had just occurred at Nutrias soon after our arrival on the Apure which created for a time great excitement even amidst that scattered population