First Launch Of GW's Nimbex Muscle Relaxant

Glaxo Wellcome's new neuromuscular blocking agent Nimbex (cisatracurium besylate) has been launched in the UK, its first market. The product is indicated for use in general anesthesia to facilitate tracheal intubation and to provide muscle relaxation during surgery or mechanical ventilation. The drug is suitable for use all types of procedures and in all types of patient, owing to its unique characteristics.

Cisatracurium is a single-isomer form of GW's established neuromuscular blocker Tracrium (atracurium), and like its parent is a non-depolarizing agent, competing with acetylcholine for receptor sites at the level of the post-junctional membrane.

Before the introduction of atracurium and a related compound, vecuronium, in 1982 neuromuscular blockade was achieved using either depolarizing agents, ie suxamethonium, which offered rapid induction and a short duration of action, or older non-depolarizing drugs with a long duration of action and more side effects. Atracurium was well-received as it had an intermediate duration of action, so that patients would regain muscle and breathing control fairly quickly, but more importantly was metabolized independently of the liver or kidneys (a phenomenon known as Hofmann or spontaneous elimination). This meant that there was no need for dosage adjustment if the patient had impaired renal or hepatic function.